Academic literature on the topic 'Cement grades'
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Journal articles on the topic "Cement grades"
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Maruthachalam, D., S. C. Boobalan, and M. Kaarthik. "Experimental Investigation on Grades of Cement in the Nominal and Design Concrete Mixes." Journal of Physics: Conference Series 2070, no. 1 (2021): 012169. http://dx.doi.org/10.1088/1742-6596/2070/1/012169.
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Abstract In India, the experience in the use of concrete in housing is more than seven decades old. Concrete mix is a combination of cement, water and aggregates of sand and stone. The relative merits of using 33, 43 & 53 grades of cement in the nominal and design concrete mixes are studied, by testing to destruction hundreds of cubes, cylinders and prisms made using these three grades of cement, the concrete mix having been designed as per the relevant Indian Standard code of practice. The objective of this paper is to make awareness among researchers, engineers and the public about the latest scientific and technical developments in cement, and how to achieve economy in concrete. The foremost objective of concrete mix design is to hand-pick the optimum proportions of various ingredients of the concrete to satisfy the required properties in its fresh and hardened state. As per the investigation, if concrete mixes are designed for different grades adopting separately 33, 43, & 53 grades of cements, grade 53 gives the highest 28 days cube strength, whereas 33 grade cement gives the lowest value. The relative cost of using these three grades is also discussed in the paper.
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Khan, Abdul Azeez, Sharath Babu Khedagi, and Santosh R. "Influence of Grades of Cement on Strength of Concrete as per IS 10262-2019." International Journal for Research in Applied Science and Engineering Technology 10, no. 9 (2022): 1550–59. http://dx.doi.org/10.22214/ijraset.2022.46879.
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Abstract: Concrete is the most used material in the world for construction. As we know Cement is the major constituent of concrete which is produced by natural raw materials like limestone rock, clay and chalk etc. Cement is produced in various grades and types used for construction according to the requirement. According to various grades used the strength of the concrete is influenced. The present investigation deals with the development of mix design of concrete using the IS 10262 - 2019. The study mainly focuses on the discussion of strength characteristics of concrete when various grades of cements used with reduction of 5% & 10% to understand if the concrete reaches the required target strength. It also focuses on understanding as to which grade of cement would be able to reach the required strength with less cement content. Compression test and Split Tensile test were conducted for strength analysis. The research evaluates the variation in Mix Design Guidelines between IS 10262-2009 & IS 10262-2019; strength factors of hardened concrete, by using various grades of cement at different percentages for M30 grade concrete at different ages. From this study it can be concluded that, 53 grade gives the better compressive strength with lesser amount of cement content, hence it is suggested that 53 grade cement can be used wherever bulk or mass concreting is done or concrete is produced
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Malak, Irshad Ali, Tulsi Das Narwani, Bashir Ahmed Memon, Jan Muhammad Wato, Naeem Ahmed Jokhio, and Sajid Ali Mallah. "Effect of Coarse Aggregate Gradation on the Strength Properties of Bagasse Ash Concrete." Engineering, Technology & Applied Science Research 13, no. 3 (2023): 10820–27. http://dx.doi.org/10.48084/etasr.5807.
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This study investigated the coarse aggregate grades and the use of sugarcane bagasse ash as a replacement for cement to examine their effect on concrete strength. Ten concrete mixes were prepared in two groups using a 1:2:4 mix ratio and a 0.48 water-to-binder ratio. Sugarcane bagasse ash was used in 0 and 10% dosages by weight of cement. Five grades of aggregates were used: 4.75-7, 7-10, 10-13, 13-20, and 4.75-20mm. Six 6"/12" concrete cylinders were prepared for each group and cured for 28 days to test their compressive and split tensile strengths. The results showed that bagasse ash caused a reduction in strength properties in both well- and specific-graded concrete. It was also observed that 10-13mm aggregate concrete with and without bagasse ash had more strength than the respective well-graded. Although a minimum decrease in strength was observed, a 10% dosage of sugarcane bagasse ash was optimal to save cement content in both specific and well-graded aggregate concrete. This study provides a new framework for using graded coarse aggregates and replacing cement with bagasse ash.
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Fapohunda, C. A., B. I. Famodimu, B. C. Adigo, and A. S. Jeje. "Effect of Changing Cement Grade on the Properties of Structural Concrete." Nigerian Journal of Technological Development 17, no. 3 (2020): 197–204. http://dx.doi.org/10.4314/njtd.v17i3.6.
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Many research efforts have been carried out, in a quest to produce mix design information that will guide the concrete and construction industry on how to achieve different concrete strengths, using the different grades of cement available. This is with a view to arresting the rampant collapse of buildings in Nigeria. The work presented in this paper is the result of investigation carried out to determine effects of changing cement grade, while casting a structural member, on the strength behaviour of the concrete. Two types of cement grades: 32.5 R and 42. 5 R were used for this research. In this investigation, the chemical and physical properties of the cement were determined. Consistency and setting times of mortar specimens from the two cement grades were also determined. Concrete samples made from the two cement grades 32.5 R and 42.5 R were evaluated for workability, density, compressive and tensile strengths at water/cement ratios of 0.40, 0.50 and 0.60. The results showed that the cement grade 42.5 consistently developed higher densities at all the water/cement ratios considered. This may be as a result of unforeseen additional dead load at the design stage, which would now amount to underestimation of dead load and thus design load. The results also showed that at higher water/cement ratios, the cement grade 42.5 R has densities exceeding the 2400 kg/m3 recommended by BS 8110. Furthermore, the concretes produced with cement grades of 32.5 R and 42.5 R have different strength development pattern and developed different 28-day compressive strength. Thus, it can be concluded that the action of changing the cement grade during concreting, for the same structural member is not supported by the national code, and will not result in safe and durable concrete.
 Keywords: Cement grades, Compressive strength, Density, Portland limestone cement, Tensile strength, Workability
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Makarenko, S. V. "Cements with low water demand as an alternative type of binding mixture used in ready-mixed concrete." Izvestiya vuzov. Investitsii. Stroitelstvo. Nedvizhimost 13, no. 1 (2023): 58–63. http://dx.doi.org/10.21285/2227-2917-2023-1-58-63.
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The paper compares Portland cement and cement with low water demand. The aim of the study was to estimate the possibility of reducing the cost of a binder and the cost of the resulting readymixed concrete, along with achieving its improved physical and mechanical properties over a short time frame. This is undoubtedly a relevant indicator, especially in winter construction, since the kinetics of concrete strength gain is one of the key factors limiting the pace of construction. The study assesses the feasibility of introducing technogenic waste and local minerals into concrete composition, as well as effectively selected structural chemistry based on polycarboxylates. Cements with low water demand of various grades were produced by grinding Portland cement and silica or carbonate filler, in the presence of the required dosage of superplasticizer and depending on the type of cement with low water demand under investigation. Based on the results of the study, the efficiency of obtaining cements with low water demand of carbonate and silica type was estimated. Kinetics of strength gain and normal density of cement-water paste of various compositions were considered. Optimal value of the specific surface area of the cement with low water demand was established. The strength dependencies of the concrete produced on the basis of low water demand cement of different grades were analyzed. The conclusions enable the effectiveness of using the binders under development to be assessed.
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Jamjoom, B., S. Patel, R. Bommireddy, and Z. Klezl. "Impact of the quantity of intradiscal cement leak on the progression of intervertebral disc degeneration." Annals of The Royal College of Surgeons of England 99, no. 7 (2017): 529–33. http://dx.doi.org/10.1308/rcsann.2017.0083.
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Introduction We aim to assess the impact of the quantity of intradiscal cement leak during kyphoplasty on the rate of progression of degenerative changes in the affected disc. Methods Of 316 kyphoplasty procedures, we identified 32 episodes of intradiscal cement leak in 26 patients. The quantity of cement leaked was graded from I to IV. Disc degenerative changes were assessed at presentation and follow-up using radiographical scoring and magnetic resonance imaging (MRI) grading systems. Data for low-grade leaks (grade I) were compared with the medium- and high-grade leaks (grades II–IV) using a chi-squared test. Results Median follow-up radiographic and MRI assessments were made at 18 and 21 months, respectively. Medium- and high-grade leaks were associated with a significantly higher radiographic disc degeneration scores compared with low-grade leaks (P = 0.04295) but no difference was found in MRI disc degeneration grades and in adjacent vertebral fracture rates. Conclusions Our findings indicate that the quantity of cement leaking into the disc space significantly influences the rate of progression of disc degeneration.
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Sanduo, T. "The Special Features of Cement Standards in China." Cement, Concrete, and Aggregates 15, no. 2 (1993): 165–69. http://dx.doi.org/10.1520/cca10604j.
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Abstract A large amount of blended cement, special cement, and shaft kiln manufactured cement is produced in China. These cements form the basis for China's cement standards. These standards have many special features and constitute a unique cement standard system. The standard cements are divided into three groups: common cement, special performance cement, and special purpose cement. As common cements, which include ordinary portland cement, portland blast-furnace cement, portland pozzolana cement, and portland composite slag cement, etc., the required and allowable blended materials incorporated in their specifications are somewhat like those in the European cement standard EN V 197, but some kinds of metallurgical slags are allowed into composite portland cement to make good use of industrial wastes, and a series of strength grades (including type R, which have higher early strength criteria) are stipulated for satisfying the various technical level of cement production and the different construction requirements. As to the special performance cement group, there are several series of cements such as portland cement, aluminatc cement, sulfo-aluminate cement, and ferro-aluminate cement, etc. The specifications for these cements are characteristic of their performance requirements: moderate-heat portland cement stipulates the criteria for heat of hydration; rapid-hardening aluminate cement defines criteria for strength within three days; expansive sulfo-aluminate cement requires criteria for rate of expansion; and self-stressing ferro-aluminate cements need criteria for self-stressing values, etc. In addition, oil well cement and masonry cement, etc., belong in the special purpose cement group. A graphical standards system is presented which includes fundamental standards, product standards, and test method standards. Owing to the different strength of the test methods, the cement strength value cannot be compared between different countries. The author suggests an international cooperative test program be organized for establishing the interrelation of mortar strength between different testing methods and the ISO method to facilitate international trade and to exchange information.
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Al-Jumaily, Mohammed Hasan. "Adapting of Performance Grading System for Local Asphalt Cement." Kufa Journal of Engineering 2, no. 1 (2014): 1–16. http://dx.doi.org/10.30572/2018/kje/211293.
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The General Specifications for Roads and Bridges (SCRB) don't adopt the performance grading (PG) based system suggested by Superpave program to evaluate the currently used asphalt cements for paving works. The air temperature data used in this study covers approximately 20 years time period (1982-2002) for seven Iraqi cities (Kirkuk, Mosul , Rutba , Baghdad , Kut , Najaf , and Basrah) which represent climatically unique regions in Iraq. The currently used asphalt cements with penetration grades (40-50) and (60-70) were tested by both of conventional test methods and Superpave methods to determine the equivalent performance grade for each type of the penetration graded asphalt and to evaluate the capability for these two types of asphalt cement to satisfy the required performance of pavement for each region of country. The paper results indicate the following for the required PG asphalt binders: Region Performance Graded (PG) Asphalt Binder North governorates 70-16 Middle governorates 70-10 West governorates 64-10 South governorates 76-4 The Daurah asphalt cements with penetration grade (40-50) are equivalent to PG 70-16, PG70-10 and PG76-4 while asphalt with penetration grade (60-70) is equivalent to PG 64-10. The rotational viscosity , dynamic shear rheometer and creep stiffness versus penetration relationships have been developed to estimate the some Superpave asphalt binder tests based on penetration values.
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Xing, Wanli. "Design of concrete mix ratio and the influence of high water absorption resin and water reducer on strength and working performance." Highlights in Science, Engineering and Technology 5 (July 7, 2022): 250–56. http://dx.doi.org/10.54097/hset.v5i.750.
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The performance of concrete and water cement ratio, water ratio and unit water consumption has a close relationship, concrete mix ratio design is actually to determine the proportion between the three, correctly determine the proportion relationship, can make concrete meet the design requirements. This paper systematically studies the working performance of concrete with different strength grades, and then compares the experimental results with the four concrete strength grades designed. High water absorption resin process increases the tightness of the slurry, to improve the working characteristics of cement, and then improve the durability of cement function. The influence of the high absorption resin curing agent and water reducing agent on different concrete strength and working performance is studied. The test data between high water absorption resin and absorbent are used to form the change curve of various strength grades, the interaction mechanism between high water absorbent resin and absorbent is analyzed, and puts forward an important scientific basis for the study of cement mix ratio.
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Sudharsan, C. Praneeth, Sayantan Gosh, and Dr Hemant Sood. "Development of Self-Compacting Concrete of Grades M25, M30 and M35 Using Composite Cement." International Journal for Research in Applied Science and Engineering Technology 10, no. 3 (2022): 2010–13. http://dx.doi.org/10.22214/ijraset.2022.41047.
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Abstract: Both fly ash and slag are industrial by-products and their disposal has become a serious environmental problem. Considering their excellent cementitious properties, their utilization in the cement industry becomes crucial. Because of the significant contribution to the environmental pollution, over dependency on cement has to be reduced. There is a need to economize the use of cement, thus, the concept of composite cement becomes necessary. In this study, Fly Ash (FA) and Ground Granulated Blast Furnace Slag (GGBFS) were used as partial replacement of cement to improve the properties of selfcompacting concrete (SCC). Three SCC grades viz., M25, M30 and M35 were made in the laboratory. For all the three grades, two variations were considered. Case 1 included 65% Ordinary Portland Cement (OPC), 15% FA and 20% GGBFS while case 2 included 85% OPC and 15% FA. In order to improve the workability of SCC, certain amount of super-plasticizer was added in the design mix. Vfunnel, L-box and slump flow tests were conducted on fresh SCC whereas compressive strength, flexural strength and split tensile tests were performed on hardened SCC. The results showed that the optimum admixture content was used their respective grades and cases leading to negligible segregation. Moreover, all the design mixes satisfied the SCC workability conditions comfortably. It was concluded that by replacing cement partially with fly ash and GGBFS in percentages mentioned in cases 1 and 2, the tensile strength of SCC could improve. From the 28 days results obtained from the compressive strength test, it was inferred that 15% fly ash and 20% GGBFS could be partially replaced with cement for all the grades i.e., M25, M30 and M35. This, could help in reducing the reliance on cement, and utilizing the industrial by-products in a better way. Keywords: Self-Compacting Concrete (SCC); Ordinary Portland cement (OPC); Fly Ash (FA); Ground Granulated Blast Furnace Slag (GGBFS); Workability; V-funnel; L-box; slump flow; compressive strength test; split tensile strength; flexural strength
Dissertations / Theses on the topic "Cement grades"
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Hatton, Drew C. "Evaluation of PCC Pavements with Cement-treated Permeable Bases and Dense-graded Aggregate Bases." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1307112876.
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Li, Yujie. "Adhesion of bituminous and cementitious materials using Particle-Probe Scanning Force Microscopy." ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1014.
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As the most important materials in civil engineering, bituminous and cementitious materials have been used widely in pavements and constructions for many years. Accurate determination of adhesion is important to the bonding properties of bituminous and cementitious materials. In this work, we presented a novel approach to measure the adhesion between binders and aggregate mineral particles at microscopic scale.
Particle probe scanning force microscopes (SFM) were used to study the adhesion between mineral microspheres representing the primary aggregate constituents (Al2O3, SiO2 and CaCO3) and various control (PG 64-22 and PG 58-22) and modified binders. Results showed that these modified SFM probes could effectively measure the adhesion between binders and aggregate minerals. Consistent adhesion measurements were obtained between different asphalt binders and aggregate mineral particles. Statistical analyses were performed to evaluate effects of different factors on the aggregate-modified binder adhesion, including aggregate constituents, binder types, modifier types and cantilever properties. Due to the stronger polarity of alumina particles, stronger interactions occur within alumina-binder pairs than within silica- and calcium carbonate-binder pairs. Meanwhile, morphologies of different modified binders clearly demonstrated microstructural variations in these binders.
The adhesion between steel and different cement hydrated products was measured using particle probe SFM. Adhesive forces are collected between steel microspheres and new (four-week old) and old (six-month old) cement in air and saturated lime water. Mixed Gaussian models were applied to predict phase distributions in the cement paste, i.e., low density C-S-H, high density C-S-H, CH, other hydrated products and the unreacted components. For new cement in saturated lime water, adhesive forces between steel and low density C-S-H, high density C-S-H and other hydrated products are intermediate among all groups selected. The adhesive forces between steel and calcium hydroxide are smallest, whereas the adhesive forces between steel and the unreacted phases are largest. For the six-month old cement, the interweaving of calcium carbonate crystals and C-S-H during the carbonation produces greater adhesive forces to steel, consistent with the adhesive forces between steel and the control calcium carbonate specimen. CH turned into calcium carbonate by reacting with carbon dioxide in air. An increase in adhesive forces was found between steel and calcium carbonate in the old cement than those between steel and CH in the new cement.
Particle probe SFM is able to measure the adhesion in bimaterials. For bituminous materials, this methodology provides opportunities to evaluate the effects of different processing methods and to generate quantitative information for the development of multi- scale asphalt mixture cracking models. For cementitious materials, these studies opened new avenues to study the interactions between steel and cement at microscale under a variety of environmental conditions and can be formulated as crack initiation and propagation criteria incorporated in multiscale models for reinforced concrete structures.
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Abbas, Abbas Musa. "Stiffness and deformation properties of asphalt open graded friction course containing cement coated natural aggregates." Thesis, Liverpool John Moores University, 2010. http://researchonline.ljmu.ac.uk/5982/.
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The primary objective of this research study was to observe the changes in the physical properties of cement coated secondary aggregates, namely surface roughness and angle of internal friction and how these properties are related to the performance of Open Graded Friction Course asphalt mixtures, OGFC made from these materials under laboratory Uniaxial, deformation and rutting testing simulating the traffic loading and temperature of the materials in service. The secondary aggregates, namely Croxden natural gravel aggregates, which is rejected by road engineers for use in road surfacing was upgraded with a specifically designed cement coating. Asphalt mixtures mechanical properties in terms of stiffness modulus, deformations and rutting were determined and analyzed using state-of-the-art laboratory test equipment and supported by technical literature from different information and resources. Three aggregate types were considered in this study; Arcow rock crushed aggregates( as a control aggregate), Croxden aggregate (as a secondary or low quality aggregates) and cement coated Croxden aggregate (as an upgraded material). One aggregate gradation was designed for all mixture types and the adopted aggregate gradation had a nominal maximum aggregate size (NMAS) of 14mm. Two binder types were selected, 100/150 pen binder and 40/60 pen binder to represent the soft and hard binders respectively that are commonly used by road engineers. This research also documents a survey of literature review that led to the design of a novel machine that is eagerly needed by the pavement industry to boost the knowledge and understanding of real tyre-road interaction. Computer software, SOLIDWORKS, was used to create a 3-dimentional model of the machine that was jointly named by the Highway Agency and Tarmac ltd., as Low Cost Asphalt Tasting Equipment (LoCATE). The machine was designed for use and for the first time to investigate the performance of the said mixtures under real traffic loading and environmental conditions and to correlate its results with those obtained using Repeated Load Indirect Tensile Test (RLIT) and Repeated Load Axial Test (RLAT), which were carried out at 10°C, 20°C, 30°C and 45°C. At an advanced stage of this research work and when the cost of fabricating LoCATE was found impossible to be met by LJMU, wheel tracking tests were done on the materials studied as a replacement of LoCATE and this part of the research program was achieved at Wolverhampton's bituminous testing laboratories in collaboration with Tarmac Ltd. In general, the results of this research investigation indicate that the introduction of cement coated aggregates to OGFC led to an outstanding improvement in the chemical properties of the coated natural aggregates and the stiffness and deformation properties/resistance of the road mixtures containing them. This was in comparison with that made from the uncoated aggregates in all the tests that have been carried out within this research study. Also, the effects of elevated temperature were investigated and it was found to have significant influence on the engineering properties, Indirect Tensile Stiffness Moduli (ITSM) and permanent deformation/rutting characteristic of the mixtures were also investigated. Outstanding new results were achieved, using LJMU cement coating paste for coating the waste natural aggregate and as thus this will hopefully eliminate the restriction imposed by road engineers on the use of natural gravel aggregates in road pavement surfacing layers. This is an outstanding knowledge extension in this field and marks a starting point for more research in this ever growing industry i. e. the use of waste and recycled aggregates in construction industry.
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Tixier, Raphaël. "Etude mineralogique et mecanique de la phase liante de graves routieres." Toulouse 3, 1987. http://www.theses.fr/1987TOU30133.
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Comparaison des caracteristiques mineralogiques et des proprietes mecaniques de melanges equiponderaux de fillers calcaires, dolomitiques ou quartzeux avec 5 liants : ciment portland, ciment alumineux, ciment au laitier, cendres volantes chaux eteinte et fumees de silice condensees chaux residuaire. Evocation d'un nouveau liant routier, par melange de cendres volantes, fumees de silice condensees et chaux (l'additivite des proprietes se realisant pour des proportions particulieres)
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Rezaeian, M. "A geotechnical evaluation of monotonic and cyclic loading of a compacted well-graded granular material with and without cement." Thesis, University College London (University of London), 2016. http://discovery.ucl.ac.uk/1519752/.
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Soil reinforcement has been, since the beginning of the last century, one of the most attractive type of material for engineers. It allows the soil properties to be changed to better suit the requirements of the structure being built. Despite the high embodied carbon, Portland cement is still widely used to improve the strength of soils and, more importantly, reduce the maintenance frequency of infrastructure assets, this, in return, may justify its application. In this research, a comprehensive laboratory triaxial testing programme was developed, in order to better understand the behaviour of a cemented and un-cemented crushed limestone, used as base and sub-base in UK. The material is well graded and the samples were prepared by dynamic compaction, very dense state, with 0, 1 and 2% of cement. The triaxial tests were performed under a variety of confining stresses, monotonic shearing and cyclic stress ratios. Results derived from the monotonic shearing were interpreted using critical state soil mechanics concept, including the changes in peak strength, changes in stiffness, yielding points, stress-dilatancy behaviour, etc. Similar samples were tested under a high number of cyclic loading and different stress ratios. To evaluate the effect of the cyclic shearing on the samples, monotonic shearing was performed afterwards and also interpreted in the same way. The cyclic stage was interpreted based on shakedown theory and the methodology proposed by BS EN 13286-7 (2004) in order to rank the material behaviour. It was also shown that particle breakage was as low as did not change the results. Distinct critical state lines, for different cement contents, were found, regardless of the shearing method used. The results also show that the addition of cement is beneficial to the behaviour of the soil, stabilising the mixtures by reducing the volume changes during the cyclic stage. This improves the long term performance of these materials in the long term, by reducing maintenance costs.
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Azorín, Carrión Antonio. "Grandes silos de almacenamiento de clínker: análisis y priorización." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/59525.
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[EN] Selecting an appropriate material storage system typology, for the raw material as well as for the products resulting from the manufacturing process, is essential for the management of production and control stock processes. Nowadays there are several available techniques applied in cement industry for storing clinker, such as silos dome, longitudinal stores, round silos or circular stores. The selection of the silo typology to be used has traditionally been based on the project manager own experience and on purely economic factors. However, the election depends not only on commensurable criteria, such as the construction cost, but also on intangible and not easily quantifiable factors which sometimes come into conflict with each other.
This thesis proposes an expert system to determine the optimal silo typology for storing 50,000 tons of cement clinker. A hybrid approach is applied in which the Delphi method and the Analytic Hierarchy Process (AHP) are used, taking account of a group of experts, to assess the selection factors and the possible alternatives for clinker storage. Finally, the proposed methodology uses VIKOR technique to establish the most adequate storage facility according to these criteria for the studied case and to guarantee stability condition.<br>[ES] La selección de la tipología más apropiada para sistemas de almacenamiento de materiales, tanto de las materias primas como de los productos resultantes del proceso de fabricación, es esencial para el control de la producción y la gestión de stocks. Hoy en día, en la industria del cemento existen varias técnicas aplicadas al almacenamiento de clínker, como son el silo domo, el almacén longitudinal, el silo cilíndrico o el depósito circular. La selección de la tipología de silo a emplear se ha basado tradicionalmente en la propia experiencia del responsable del proyecto y en factores puramente económicos. Sin embargo, la elección del sistema óptimo depende no sólo de criterios conmensurables como el coste de construcción, sino también de factores intangibles y difícilmente cuantificables que en ocasiones entran en conflicto entre sí.
En la presente tesis doctoral se propone un sistema experto para determinar la tipología óptima de silo, aplicándose a un caso concreto en el que se pretende almacenar 50.000 toneladas de clínker. Se aplica un método híbrido en el que la técnica Delphi y el Proceso Analítico Jerárquico (AHP) son empleados para, apoyándose en un grupo de expertos, establecer y evaluar los criterios de selección así como las posibles alternativas para el almacenamiento de clinker. Por último, la metodología propuesta se sirve del método VIKOR para determinar la tipología de almacenamiento de clínker más adecuada para el caso de estudio, garantizado las condiciones de estabilidad para la solución obtenida.<br>[CAT] La selecció de la tipologia més apropiada per a sistemes d'emmagatzematge de materials, tant de les matèries primeres com dels productes resultants del procés de fabricació, és essencial per al control de la producció i la gestió d'estocs. Avui en dia, en la indústria del ciment existeixen diverses tècniques aplicades a l'emmagatzematge de clínquer, com són la sitja dom, el magatzem longitudinal, la sitja cilíndrica o el dipòsit circular. La selecció de la tipologia de sitja a emprar s'ha basat tradicionalment en la pròpia experiència del responsable del projecte i en factors purament econòmics. No obstant això, l'elecció del sistema òptim depèn no només de criteris commensurables com el cost de construcció, sinó també de factors intangibles i difícilment quantificables que en ocasions entren en conflicte entre si.
En la present tesi doctoral es proposa un sistema expert per determinar la tipologia òptima de sitja, aplicant-se a un cas concret en el qual es pretén emmagatzemar 50.000 tones de clínquer. S'aplica un mètode híbrid en què la tècnica Delphi i el Procés Analític Jeràrquic (AHP) són emprats per, recolzant-se en un grup d'experts, establir i avaluar els criteris de selecció així com les possibles alternatives per a l'emmagatzemament de clínquer. Finalment, la metodologia proposada es serveix del mètode VIKOR per determinar la tipologia d'emmagatzematge de clínquer més adequada per al cas d'estudi, garantit les condicions d'estabilitat per a la solució obtinguda.<br>Azorín Carrión, A. (2015). Grandes silos de almacenamiento de clínker: análisis y priorización [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59525<br>TESIS
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Lee, David Robert. "Genesis of fault hosted carbonate fracture cements in a naturally high CO2 province, South Viking Graben, UK North Sea." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7817.
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The Late Jurassic Brae oilfields in the South Viking Graben of the northern North Sea contain naturally high concentrations of carbon dioxide (up to 35 mol %). Fields immediately adjacent to the graben bounding fault display the highest concentrations, with CO2 content decreasing eastward into the basin. It is thought the CO2 was introduced into the region via this fault. This thesis examines the possible source of the high CO2 present in the region, focusing on the graben margin fault as a potential conduit for CO2 flux from depth Investigation of cored sections penetrating the graben bounding fault revealed numerous carbonate cemented fracture arrays. The morphology of the fractures and cements is attributed to hydraulic fracturing induced by episodic release of overpressured fluids up the margin fault from depth. Periods of rapid subsidence omnipresent throughout the tectonic history of the graben are conducive to the generation of overpressure; a feature commonly reported in the region. Samples from the carbonate fracture cements were analysed using a host of techniques, including SEM, EMPA, fluid inclusion, and stable δ13C ‐ δ18O analyses. Using SEM analysis, at least five generations of dolomite cement with concomitant iron sulphide were observed. Cement chemistry and textures indicate precipitation from concentrated CO2–rich fluids. A reported high salinity basinal influx from depth concomitant with proposed CO2 charge into the region ~70 Ma is a probable source for the dissolved solids subsequently precipitated as carbonate in the fracture networks. Fluid inclusion analysis provided sufficient evidence to suggest the influx of hot fluids into the region, presumably sourced from deep in the margin fill. Two distinct δ13C vs. δ18O trends are observed in the isotope data from four wells studied. The trends are interpreted as differential mixing between ascending basinal fluids rich in dissolved inorganic carbon and in situ formation waters dominated by organically derived carbon following the onset of thermal decarboxylation in the Kimmeridge Clay Formation. Dissolution of Zechstein carbonates underlying the region is a credible source for the isotopically heavy CO2 found adjacent to the graben margin (δ13CCO2 = ‐2 to ‐5 ‰) and incorporated into the carbonate cements. Inferred variations in fluid mixing from well to well have implications on the variability of fluid flow along the graben margin with respect to contrasting fault morphologies. A Rayleigh fractionation model accommodating CO2 degassing from a hot ascending isotopically heavy fluid can be invoked to explain the observed carbon‐oxygen isotopic covariations in the fracture cements. Geochemical modelling simulating the ascent of CO2‐rich waters suggests degassing has limited impact on precipitation volumes, with fluid‐rock reactions the most likely driver for extensive carbonate mineralisation observed.
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Giordano, Brunoro Leite. "Controle da fissuração em compósitos com fibras orgânicas aplicando conceito de materiais com gradação funcional." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-20092012-182239/.
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O objetivo deste trabalho é controlar a incidência de fissuras em fibrocimentos aplicando o conceito de materiais com gradação funcional através da protensão química gerada pela aplicação de silicato de sódio alcalino entre as camadas dos fibrocimentos. Atualmente é bastante comum os fibrocimentos apresentarem fissuras ao longo das bordas devido aos gradientes de umidade gerados durante a estocagem das pilhas de telhas no pátio das indústrias. O potencial da protensão química foi avaliado através da porosidade total, da quantificação das fases hidratadas, da retração por secagem e do desempenho mecânico. A aplicação de silicato de sódio alcalino no ligante CPII F provocou retração por secagem 1,5 vezes maior que a referência aos 91 dias. O módulo de ruptura (MOR) não sofreu alteração, mas o limite de proporcionalidade da matriz (LOP) aumentou em torno de 95%. O módulo de elasticidade dinâmico foi 13 % maior. O aumento da retração por secagem e o ganho de desempenho mecânico apontam o potencial da protensão química para o controle da fissuração em fibrocimentos produzidos pelo processo Hatschek.<br>The objective of this work is controlling the incidence of cracks in fiber cement, using the concept of functionally graded materials through the chemical prestressing, generated by application of alkaline sodium silicate among fiber cement layers. Currently, its very common the fiber cements present cracks along the edges due to moisture gradients, caused during storage of piles of tiles in the courtyard of the industry. The chemical prestressing potential was evaluated through of the total porosity, the quantification of hydrate phases, the drying shrinkage and the mechanical performance. The application of alkaline sodium silicate in the cement CPII F caused drying shrinkage 1,5 times greater than the reference to 91 days. The modulus of rupture (MOR) didnt suffer change, but the proportional limit of matrix (LOP) increased by around 95%. The dynamic modulus of elasticity was 13% higher. The increase of drying shrinkage and the mechanical performance gain indicate the chemical prestressing potential to control the cracking in fiber cement produced by the process Hatschek.
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Pacltová, Klára. "Ověřování vlastností betonů s nanočásticemi." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392361.
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This diploma thesis deals with the influence of addition of carbon nanoparticles on cement composites. The theoretical part of the diploma thesis is focused on the research of information about carbon nanoparticles, more precisely about carbon nanotubes and graphene oxide. There are summarized methods of dispersing carbon nanotubes and their effects on cement composites. The practical part follows the theoretical part of the research. In the first phase, the correct technique of graphene oxide dispersion was verified. Subsequently, the effects of graphene oxide on the mechanical properties of cement mortars were verified. In the final phase of the diploma thesis, the knowledge gained from the previous part was verified on concrete samples.
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Dias, Cleber Marcos Ribeiro. "Fibrocimentos com gradação funcional." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-31052011-164232/.
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O presente estudo mostra que o conceito de materiais com gradação funcional (MGF) pode ser aplicado no desenvolvimento de componentes de fibrocimento mais econômicos e com desempenho mecânico melhorado. Primeiramente, este trabalho estabelece o conceito de fibrocimento com gradação funcional. Depois, modelam-se, em elementos finitos, as tensões em telhas onduladas sob flexão estática e cargas de vento e mostra-se que, para esses tipos de carregamento, regiões específicas das telhas são submetidas a tensões de baixa intensidade justificando a aplicação do conceito de MGF para a otimização da distribuição da resistência em tais componentes. A parte experimental deste trabalho é constituída de quatro estudos: a) produção de fibrocimentos com o teor de fibras variando ao longo da espessura; b) desenvolvimento de um método de escolha de formulações para fibrocimentos com gradação funcional; c) desenvolvimento de compósitos cimentícios para extrusão em altas velocidades, destinados a gradação de fibrocimentos; e d) aplicação pré-industrial para avaliar a aplicabilidade de técnica de modificação local das propriedades de telhas com gradação funcional. Mostra-se, experimentalmente, que fibrocimentos contendo 1,0% de fibras de PVA, em massa, estrategicamente distribuídas ao longo da espessura, apresentam módulo de ruptura (MOR) similar ao dos fibrocimentos homogêneos com 1,8% de fibras, comprovando a eficácia deste tipo de gradação na redução do custo de placas de fibrocimento. O segundo trabalho experimental avalia formulações de fibrocimento constituídas de seis matérias-primas empregando-se a estratégia screening, uma metodologia promissora para gerar regras de mistura, otimizar custos e desempenho e facilitar a escolha de formulações locais para fibrocimentos com gradação funcional. Compósitos cimentícios com fibras de PVA ou vidro álcali resistente (AR), destinadas à extrusão em altas velocidades, foram desenvolvidos para aplicação pré-industrial. Aqueles contendo 4,0% de fibra de vidro, em volume, apresentaram resistência à tração média igual a 12,0 MPa, enquanto compósitos com 3,0% de fibras de PVA apresentaram resistência igual a 7,5 MPa. A aplicação destas misturas entre as camadas de telhas onduladas de fibrocimento, durante o experimento pré-industrial, resultou em melhoras substanciais do desempenho local.<br>The present study applies the functionally graded materials (FGM) concept on the development of fiber cements as an alternative to improve the mechanical performance and reduce cost of production of asbestos-free corrugated sheets. Primarily, this work establishes the concept of functionally graded fiber cement. Then, finite element modeling (FEM) is applied in the evaluation of the stresses distributions in corrugated sheets under bending and static wind loads. The simulations show that for these load cases, some regions of corrugated sheets are submitted to low stress intensities what justify the application of FGM concept for optimization of the strength distribution in such components. The experimental part of this work consists of four different studies: a) production of functionally graded fiber cements with gradation through thickness; b) development of a method for choosing formulations in functionally graded fiber cements; c) development of fiber reinforced cementitious composites for high speed extrusion and; d) pre-industrial application to evaluate the suitability of functionally graded fiber cements production. The first experimental study shows that functionally graded cementitious composites with 1.0% of PVA fibers, in mass, strategically distributed through thickness, presented similar modulus of ruptures (MORs) to that homogeneous ones with 1.8% of PVA fibers what proves that gradation of fiber content through thickness is a good approach to reduce cost of fiber cement pads without affecting the mechanical performance of the composite. The second experimental work examines sixcomponent fiber cement formulations employing the screening strategy which is a promising methodology to generate coherent mixture rules, optimize cost and performance and even facilitate the choosing of formulations for functionally graded fiber cements. PVA fibers and glass fiber reinforced cementitious composites for high speed extrusion were developed forpre-industrial application. Composites with 4.0% of alkali-resistant (AR) glass fiber, in volume, presented average tensile strength of 12.0 MPa while composites with 3.0% of PVA fibers presented 7.5 MPa. The application of these mixtures between layers of fiber cement corrugated sheets results in improvement of the performance of the product.
Books on the topic "Cement grades"
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Chamberlin, William P. An open-graded friction course on portland cement concrete base: A seven-year progress report. Engineering Research and Development Bureau, NYS Dept. of Transportation, 1986.
Find full textBook chapters on the topic "Cement grades"
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Asadi, Iman, Guomin Ji, Gerald Steiner, and Mohammad Hajmohammadian Baghban. "The Effect of Phase Change Materials (PCM) on the Thermophysical Properties of Cement Mortar." In Lecture Notes in Civil Engineering. Springer Nature Switzerland, 2025. https://doi.org/10.1007/978-3-031-69626-8_37.
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AbstractCement mortar, a fundamental material in construction, requires advancements to enhance its energy efficiency. Phase change materials (PCMs) offer promise in this regard due to their high thermal energy storage capacity. However, challenges persist in integrating PCMs into cement-based materials. Microencapsulated phase change materials (MPCMs) present a solution to these challenges. This study evaluates the impact of MPCMs on the properties of cement mortar with various grades (cement-to-sand ratio of 1:2, 1:3, and 1:4), including mechanical, physical, and thermal characteristics. Through regression analysis, predictive equations are derived to estimate key properties based on the cement-to-sand ratio and MPCM content.
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Lee, Kevin Jia, and Sook Fun Wong. "Recycled Mixed Plastic Fine Aggregate in Cement Concrete." In Springer Proceedings in Materials. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-72955-3_9.
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AbstractThe literature extensively examines the utilization of sorted single-type plastic waste from post-consumer waste streams as a sustainable substitute for natural sand in cement concrete. However, severe heterogeneity of plastic waste in municipal solid waste streams, including variations in polymer types, grades, shapes, sizes, and cross-contamination with other commingled waste materials, poses a significant challenge in adopting findings from prior research that necessitates high-purity single-type plastic waste for concrete applications. This paper reports the characterization of cement concrete incorporated with mixed plastic fine aggregate (rMPFA) containing an optimized blend of plastic types produced using a proprietary mixed plastic recycling process. Five concrete mixtures containing 0% (M0), 10% (M10), 20% (M20), 30% (M30), and 40% (M40) rMPFA by volume of natural sand were investigated in this study. The laboratory results show that concrete mixture M20 had comparable compressive strength and water penetration test results when compared to control mixture M0. Additionally, toxicity characterization of concrete mixture M20 demonstrated a reduction of heavy metals in the leachate solution when compared to control mixture M0. Furthermore, microplastic detection analysis results of concrete mixtures M0 and M20 were comparable and stable.
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Ghorui, Chandan, Koalla Rajesh, P. Naveen Kumar, and A. K. Chaudhary. "Study of Optical Properties of Different Grades Indian Cement Samples Using Terahertz Spectroscopy." In Proceedings of 28th National Conference on Condensed Matter Physics. Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-5407-7_14.
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Avet, F., and K. Scrivener. "Hydration Study of Limestone Calcined Clay Cement (LC3) Using Various Grades of Calcined Kaolinitic Clays." In RILEM Bookseries. Springer Netherlands, 2017. http://dx.doi.org/10.1007/978-94-024-1207-9_6.
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Zhou, Jian. "Research and Application of Ultra High Performance Concrete in Engineering Projects in Japan." In Lecture Notes in Civil Engineering. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1748-8_23.
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AbstractJapan is located in the international seismic zone, and is also a resource intensive country. It has unique features in the research and application of ultra-high performance concrete materials. The paper analyzes and summarizes the engineering application cases of concrete strength grade above 150 N/mm2, including structural system, mix design, production process, strength grade, etc. Silica fume composite cement, with strict calculation of sand and stone gradation, improves the compactness beyond the conventional concrete; The super high performance water reducing agent can greatly reduce the water cement ratio and improve the working performance, especially the expansion degree; Organic fiber and steel fiber are especially important in fire resistance, explosion resistance and ductility. Ultra-high performance concrete could improve the seismic performance of building structures and the utilization rate of building area, and new materials could provide more choices for design and engineering application.
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Bansal, Ankit, Tripta Goyal, and Umesh Sharma. "Enhancement of Sub-grade Soil Strength with Additives: Cement and Molasses." In RILEM Bookseries. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-51485-3_4.
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Zhou, Guoxu, Zhijun Huang, Wei Chen, Yongguan Wan, Yuting Song, and Ersheng Zhao. "Study on the Effect of Cement Graded Gravel Pile on Treating Loess Foundation." In Advances in Engineering Research. Atlantis Press International BV, 2023. http://dx.doi.org/10.2991/978-94-6463-336-8_52.
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Chauhan, Amitkumar R., and Manu Santhanam. "Potential Strength and Durability of Blended Low-Grade Limestone Calcined Clay Cement Concrete." In RILEM Bookseries. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-53389-1_62.
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Yang, Zhihao, Linbing Wang, Dongwei Cao, Rongxu Li, and Hailu Yang. "Test and Evaluation for Performance of Composite Pavement Structure." In Lecture Notes in Civil Engineering. Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1260-3_25.
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AbstractPerpetual pavement has become an important research field of highway development in China. Reasonable selection of pavement structure and ensuring the durability of the structure are one of the necessary measures to build perpetual pavements. The inverted asphalt pavement structure can not only provide high strength and good bearing capacity of semi-rigid base, but also make use of the graded crushed stones for restraining the reflection cracks of semi-rigid base. This paper presented a study on three pavement structures are, namely, a semi-rigid asphalt pavement and two inverted asphalt pavements. The performances of the three pavement structures after one million loading repetition are obtained. Taking rutting depth, deflection and dynamic response as evaluation indexes, the feasibility of inverted asphalt pavement structure as perpetual pavement structure is evaluated. It is found that the composite asphalt pavement structure with permeable asphalt mixture of large particle size as base and cement stabilized macadam as subbase has the best performance as perpetual pavement.
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Uchimura, T., Y. Kuramochi, and T. T. Bach. "Bending tests on a beam of grid-reinforced and cement-mixed well-graded gravel." In New Horizons in Earth Reinforcement. CRC Press, 2023. http://dx.doi.org/10.1201/9781003416753-116.
Full textConference papers on the topic "Cement grades"
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Thejani, K. W. D., and K. Baskaran. "Performance Evaluation of Sustainable Cement Types in various Concrete Grades." In 2024 Moratuwa Engineering Research Conference (MERCon). IEEE, 2024. http://dx.doi.org/10.1109/mercon63886.2024.10688710.
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Delitsyn, Leonid, Mikhail Sulman, Ruslan Kulumbegov, Oleg Popel, and Alexander Sidorov. "UTILIZATION OF ASH FROM THE COMBUSTION OF KUZNETSK AND EKIBASTUZ COALS." In 24th SGEM International Multidisciplinary Scientific GeoConference 24. STEF92 Technology, 2024. https://doi.org/10.5593/sgem2024/4.1/s18.44.
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One of the promising areas of utilization of solid technogenic waste from energy generation is their processing to produce alumina, the production of which is accompanied by the formation of by-products that can be used to produce belite sludge (2CaO�SiO2). The basic schemes of purification of the initial ash from carbon and iron oxides are proposed. Using the example of ash from coal burning in the Ekibastuz basin, the possibility of obtaining two grades of belite sludge is shown. Up to 1.5-1.8 tons of belite sludge can be obtained per ton of recycled ash (depending on its quality), which can be used in cement production. The article presents the results of experimental studies aimed at developing a technology for producing belite sludge from high-alumina ash from coal-fired power plants. The influence of various technological parameters on the process of obtaining the target product has been studied. A solution of sodium silicate with the extraction of 28% silica into it was obtained by the method of alkaline desilination of ash. The possibility of obtaining a white, high-quality belite sludge suitable for the production of white cement by treating a solution of sodium silicate with calcium oxide is shown. At the second stage, during the processing of alumina concentrate, gray belite sludge was obtained suitable for use in the construction industry
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Morefield, Sean W., Charles A. Weiss, Philip G. Malone, and Mike Koenigstein. "Reactive Silicate Coatings for Protecting and Bonding Reinforcing Steel in Cement-Based Composites." In CORROSION 2009. NACE International, 2009. https://doi.org/10.5006/c2009-09492.
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Abstract Engineered glass-ceramic coatings that contain hydraulically reactive calcium silicates have been shown to be remarkably effective in increasing the bond strength between reinforcing steel and the surrounding concrete or mortar. The coatings are a mixture of portland cement and alkaline-resistant basecoat glass enamel. X-ray diffraction patterns indicate that all of the major reactive compounds, such as dicalcium silicate and tricalcium silicate and the ferrites and even gypsum survived the firing of the frit-cement mixture onto steel. When exposed to water the cement grains in contact with water hydrated to form gel products similar to those produced in hydrating normal cement paste. The hydration of the layer of cement appears to remove the “wall effect” and the bond strength between the concrete and steel is increased up to four times that developed with uncoated steel. The enamel over the steel isolates the metal and produces durable corrosion protection. A SEM study of cracks purposely produced in the enamel indicates the embedded cement grains will hydrate when moisture contacts them and produce hydration products that can fill fractures and raise the pH at the steel surface.
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Panda, Krutibas, Ed Rusnica, Reece Goldsberry, Jerry Domingue, Paul Prichard, and Zhuqing Wang. "Mechanical, Microstructural and Corrosion Characterization of Low Binder Containing WC-Co Grades Using a Binderjet Process." In CONFERENCE 2022. AMPP, 2022. https://doi.org/10.5006/c2022-17583.
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Abstract Cemented Tungsten carbides (WC-X) have been a mainstay for wear components across many different industries including oil & gas. These ceramic-metal (cermet) systems can be widely tailored to optimize their wear resistance, corrosion resistance and toughness properties to suit their functional requirements. Conventional powder metallurgy has been the process of choice for these cermets whereby tungsten carbide powder along with a choice of metallic binder (cobalt, nickel, or alloyed binder) are pressed into a desired shape and subsequently sintered. There are manufacturing limitations to traditional powder metallurgy for parts containing high geometric complexity. In addition, secondary processing required to create complex features on press-sintered parts such as electro discharge machining (EDM) can sometime lead to micro cracking in the re-cast layer, which subsequently leads to part failure during operation. Additive manufacturing (AM) can produce cemented carbides with complex part geometry, significant weight reduction, and elimination of subsequent secondary processing to these parts. Although several AM methods have been investigated to additively manufacture cemented carbides, the present study utilized a binderjet process to manufacture two relatively low binder containing WC-Co grades; WC-17%Co and WC-13.5%(Co+Ni+Cr+Mo). The corrosion, wear, and mechanical properties of AM cemented carbides grades were characterized in the present study. Corrosion properties of the AM grades as well as their equivalent grades fabricated using conventional PM route were compared using linear polarization resistance and cyclic potentio-dynamic polarization following methods outlined in ASTM G59 and ASTM G61, respectively, in neutral 3.5% NaCl solutions. Mechanical characterization was performed using fracture toughness testing per ASTM B771 as well as transverse rupture toughness testing per ASTM B406 on these grades. Wear properties were examined according to ASTM G65 and B611. Optical and scanning electron microscopic techniques were further utilized to characterize and compare the microstructures of the samples manufactured using these two processing routes. The effect of microstructure on the resulting mechanical properties of the AM parts is also addressed in this study.
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Durig, John. "Concrete Mix Design for Coatings and Linings Acceptance." In Paint and Coatings Expo (PACE) 2009. SSPC, 2009. https://doi.org/10.5006/s2009-00009.
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Abstract Successful coating and lining application on concrete substrates are contingent, in part, on the basic design and installation of the concrete itself. Protective coatings and linings are effected by the amount and movement of water in the concrete, the compressive and tensile strength of the concrete and the concrete’s ability to resist cracking from internal and external forces. Through attention to sub-grade conditions, water cement ratios, aggregate grading and content, and finish and cure techniques, probability of successful coating and lining application can be greatly increased.
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Souza, João Paulo Marçal de, JESSICA DUARTE RIBEIRO VIEIRA, FABIANA ARAUJO MAIA, et al. "MODIFICAÇÃO DE CONCRETOS ASFÁLTICOS DRENANTES NA INDÚSTRIA DA PAVIMENTAÇÃO: UM ESTUDO BIBLIOMÉTRICO." In Anais da 49ª Reunião Anual de Pavimentação - RAPv. Even3, 2024. http://dx.doi.org/10.29327/1430212.49-60.
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Com o aumento do crescimento urbano nas últimas décadas, a expansão das áreas impermeáveis tornou-se uma consequência evidente. Nessa perspectiva, estudos recentes na área da pavimentação focaram em dispositivos para promover infiltração e retardar o escoamento superficial, como o pavimento de concreto asfáltico poroso, que facilita a drenagem sob o pavimento. Tendo em vista a importância das estratégias tecnológicas para a indústria da pavimentação, este estudo teve como objetivo a análise bibliométrica das publicações sobre novos materiais na pavimentação asfáltica drenante utilizando a base de dados Scopus. As análises bibliométricas aplicaram-se para conhecer a evolução e produção científica, além das tendências e domínios de conhecimento. Para a pesquisa dos documentos foram utilizados os termos em inglês “modified asphalt” and “modified asphalt concrete” or CPA or "cement replacement" or recycle or sustainab or “open graded asphalt” e considerados os artigos do período de 2000 a 2024. Os resultados revelaram o aumento das publicações com o passar dos anos, enfocando áreas específicas, materiais e países mais ativos. Houve um crescimento constante nas publicações ao longo do tempo, com destaque para a China como líder em pesquisas. Os estudos destacaram os testes de desempenho e a busca por alternativas sustentáveis, como borracha de pneus e fibras de vidro, substituindo materiais convencionais no concreto asfáltico permeável.
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Ashraf, Shameed, Martijn Bogaerts, and Haresh Mohanaraju. "Impact of Silica Blend Towards Early Compressive Strength Development of Well Cement Class G." In Offshore Technology Conference Asia. OTC, 2024. http://dx.doi.org/10.4043/34906-ms.
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Abstract In this paper we evaluate the effects of silica on early compressive strength development of well cement Class G during the first 24 hours. The paper’s scope is a 15.8 lbm/galUS system with 35% by weight of cement (BWOC) silica varied between fine, medium, and coarse grades, followed by an optimized version. The addition of silica at 35% BWOC is an accepted industry norm for exposure of 110°C or greater. Slurries are evaluated at 120 and 160°C by an ultrasonic cement analyzer (UCA) to determine the compressive strength development. API 10A compliant class G cement is added with different grades of silica with an average size of 4.5 µ (fine), 16 µ (medium), and 330 µ (coarse) at 35% BWOC separately. It is mixed according to API RP 10B-2 and the compressive strength development is evaluated using the ultrasonic cement analyzer (UCA) at 120 and 160°C. The time taken to reach 50 and 500 psi, together with the strength value at 12 and 24 hours, are compared for differing silica grades. The slurry’s rheological behavior is evaluated to eliminate unfavorable slurry properties due to silica size. Testing shows that silica size is a significant contributor to the early compressive strength development. The fine silica slurry achieved higher strength development compared to medium and coarse silica. The drawback is that the use of a fine product alone causes unacceptable high slurry gel strength. An optimized silica blend being a mixture of the three grades provides the highest compressive strength development and favorable rheological property. At 120°C, the coarse silica alone has the lowest strength at 24 hours, while the medium-sized silica provides a 49% increase over the coarse grade. The fine grade provides a 67% increase over the medium grade. The optimized silica blend can provide an additional 7% increase over the pure fine-grade silica. An evaluation done at 160°C shows that course silica provides the least compressive strength while the medium silica provides about six times the value of the medium, and the fine about 5% more than the medium. The optimized silica blend provided an additional 5% over the fine grade. Although the industry is clear about the need to add a minimum 35% BWOC of silica to prevent strength retrogression for high-temperature applications, there is little information on how silica grades affect the early compressive strength development of the cement system. This study has clarified that proper optimization of silica grades can bring out the best early compressive strength for elevated temperature applications.
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Daniels, John L., Shaogang Lei, Zhengfu Bian, and Benjamin F. Bowers. "Air-Soil Relationships for Lime and Cement Stabilized Sub-Grades." In GeoShanghai International Conference 2010. American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41104(377)42.
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Abraham, J. J., A. Carvero, C. Devers, C. Teodoriu, and M. Amani. "Stress Failure Assessment and Potential Well Integrity Issues with Different Oilwell Cement Classes and Formulations in Complex Wells." In GOTECH. SPE, 2024. http://dx.doi.org/10.2118/219117-ms.
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Abstract Complex operations such as fracturing, and stimulations have become a mainstay in most drilling and completion operations around the world. Safe technologies have been adopted by the industry to mitigate issues in complex wells, HPHT conditions and difficult formations. However, well integrity problems - especially in the cement layer - are still a major concern in a lot of cases when performing workover, fracturing or re-completion operations in existing or older abandoned wells. Oilwell cement used in drilling and completion comes in several different classes and grades. Geopolymer based cements are also increasingly being considered for cementing operations, owing to their green credentials. Commonly used API Class C, Class H and Class G cements as wells as Geopolymers all have mechanical properties which vary widely, and a decline in these properties are expected after exposure to different downhole conditions over time. Experimental evaluations were performed to measure mechanical properties such as the Uniaxial Compressive Strength (UCS) and acoustic velocities and determine how they vary over time and under different physical environments. Finite element stress modeling was then performed to determine failure mechanisms in downhole conditions. Degradation of the cement layer due to ageing, as well as exposure to different downhole temperatures especially in the cement-casing interface are of particular interest. Each of the classes of oilwell cements perform differently and thereby have a different impact on the overall integrity of the well. Results from laboratory testing of samples showed significantly different mechanical properties during the mixing, setting and ageing periods for different oilwell cement classes and at different temperatures. Among the different formulations tested, Class G cement showed the highest failure stress with almost all samples showing a consistent peak UCS growth, before stabilizing. Class C cements and Geopolymers had the lowest stress failure resistance, indicating their unsuitability for HPHT operations. Higher temperatures accelerated the setting time, though reduced the UCS for all classes of cement. When stresses experienced during typical fracturing operations were modeled in a downhole scenario with these cements, propagating failure points were observed. Stresses can migrate and concentrate at different points - which in some cases can exceed the failure criteria of these cements leading to the formation of cracks. These can in turn cause integrity issues in the cement sheath and possibly a critical well integrity situation. Robust testing of oilwell cements and geopolymers is needed to properly understand their properties, as well as the development of stress failure points around the wellbore. Identifying potential well integrity issues for various cement formulations can in turn help in improving the quality and reliability of cementing operations, reduce the risks associated and ensure safe operations over the lifespan of a well.
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"Effects of Fly Ash on Strength and Durability of Hydraulic Structures with Various Grades of Cement and Concrete." In "SP-199: Seventh CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete". American Concrete Institute, 2001. http://dx.doi.org/10.14359/10489.
Full textReports on the topic "Cement grades"
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Ucak-Astarlioglu, Mine, Jedadiah Burroughs, Charles Weiss, et al. Graphene in cementitious materials. Engineer Research and Development Center (U.S.), 2023. http://dx.doi.org/10.21079/11681/48033.
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This project aims to determine the influence of laboratory-generated graphene (LGG) and commercial-grade graphene (CGG) on the chemical structure and compressive strength of graphene-cement mixtures. Determining the graphene-cement structure/processing/property relationships provides the most useful information for attaining the highest compressive strength. Graphene dose and particle size, speed of mixing, and dispersant agent were found to have important roles in graphene dispersion by affecting the adhesion forces between calcium silicate hydrate (CSH) gels and graphene surfaces that result in the enhanced strength of cement-graphene mixtures. X-ray diffraction (XRD), Raman, and scanning electron microscope (SEM) analyses were used to determine chemical microstructure, and compression testing for mechanical properties characterization, respectively. Based on observed results both LGG and CGG graphene cement mixtures showed an increase in the compressive strength over 7-, 14-, and 28-day age curing periods. Preliminary dispersion studies were performed to determine the most effective surfactant for graphene dispersion. Future studies will continue to research graphene—cement mortar and graphene—concrete composites using the most feasible graphene materials. These studies will prove invaluable for military programs, warfighter support, climate change, and civil works.
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Hartell, Julie, Matthew O’Reilly, and Hang Zeng. Measuring Transport Properties of Portland Cement Concrete Using Electrical Resistivity. Illinois Center for Transportation, 2023. http://dx.doi.org/10.36501/0197-9191/23-012.
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Although classification tables based on susceptibility to chloride ion permeability are recommended in AASHTO T 358, the classification levels with respect to durability parameters may or may not be adequate. Of interest for concrete pavement performance, this study verifies the recommended classification levels against standard durability testing such as corrosion, salt scaling, and freeze-thaw. The researchers conducted corrosion, salt scaling, and freeze-thaw durability tests in parallel with electrical surface resistivity testing to compare performance classifications for each method. Twenty-four mixture designs were evaluated. The designs vary in water-to-cementitious material ratio (0.4, 0.45, and 0.5 w/cm ratio), supplementary cementitious material type (100% ordinary Portland cement, 20% Class C fly ash, 40% Grade 100 slag cement, and 8% silica fume replacements), and air content (air entrained and non-air entrained). The results of the experimental study indicate that there is no clear relationship between concrete electrical conductivity and durability performance based on standard methods of testing. It may not be appropriate for the determination of durability performance of a concrete mixture for concrete pavement construction. However, the test method does present advantages, as mixtures of similar composition and design can yield the same results over time under standardized curing. Here, resistivity-time curves could be a useful tool as part of a quality control and quality assurance program to ensure consistency in concrete delivery during construction.
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O'Keeffe, Michael. IS-86 Colorado Mineral and Energy Industry Activities 2022-2023. Colorado Geological Survey, 2024. http://dx.doi.org/10.58783/cgs.is86.kgin1364.
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The Colorado Geological Survey (CGS) estimates the total value of 2022 mineral and energy fuels production in Colorado to be $30.53 billion, a ~49% increase from the 2021 estimate of $20.51 billion mainly due to higher average prices for oil and natural gas. In 2022, the top commodities produced in terms of production value include: oil, natural gas, coal, molybdenum, gold, sand and gravel, cement, industrial gases (carbon dioxide), and crushed rock. Oil and natural gas production accounted for ~90% of Colorado’s total mineral and energy production value in 2022.
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O'Keeffe, Michael. IS-87 Colorado Mineral and Energy Industry Activities 2023-2024. Colorado Geological Survey, 2025. https://doi.org/10.58783/cgs.is87.pusj8408.
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The Colorado Geological Survey (CGS) estimates the total value of 2023 mineral and energy fuels production in Colorado to be $20.58 billion, a ~33% decrease from the 2022 estimate of $30.53 billion mainly due to lower average prices for natural gas. In 2023, the top commodities produced in terms of production value include: oil, natural gas, molybdenum, gold, coal, sand and gravel, cement, crushed rock, and industrial gases (carbon dioxide). Estimated mineral production values for 2023 are shown by commodity type in Figure ES-1. Oil and natural gas production accounted for ~84% of Colorado’s total mineral and energy production value in 2023.
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Jefferson, C. W., S. Pehrsson, V. Tschirhart, et al. Geology and metallogeny of the northeast Thelon Basin region, Nunavut, and comparison with the Athabasca Basin, Saskatchewan. Natural Resources Canada/CMSS/Information Management, 2024. http://dx.doi.org/10.4095/332499.
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Based on extensive remapping of the northeast Thelon Basin region in Nunavut, uranium exploration criteria are adapted from those of the Athabasca Basin in Saskatchewan, as basin-specific paradigms. The Athabasca Basin straddles the Rae and Hearne cratons and the Taltson magmatic zone, whereas the Thelon Basin rests entirely within the Rae Craton. In the Athabasca Basin, four unconformity-bounded siliciclastic sequences with different paleocurrents record a complex depositional history, whereas the Thelon Formation is a single, albeit cyclic siliciclastic unit with uni-modal paleocurrents. Beneath the Athabasca Basin, amphibolite-grade, conductive graphitic-pyritic-Paleoproterozoic units localize all major deposits. Conductor analogues below the Thelon Basin are barren, impermeable, black slate of anchizone to lower-greenschist-facies grade. Instead, the Thelon uranium deposit host rocks are Neoarchean pyritic greywacke and epiclastic rocks that range in metamorphic grade from lower- to upper-amphibolite facies. Similar mineralogical sources, saline brines, alteration (fluorapatite, aluminum-phosphate-sulphate minerals, chlorite, clays, and desilicification), and reactivated intersecting faults focused unconformity-type uranium mineralization in each basin. Previously published ages for pre-ore fluorapatite cements of the Athabasca and Thelon basins (1638 versus 1688 to 1667 Ma, respectively) reaffirm their independent diagenetic-hydrothermal histories.
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Knab, Lawrence I., and Nathaniel E. Waters. A method to measure the tensile bond strength between two weakly-cemented sand grains. National Bureau of Standards, 1988. http://dx.doi.org/10.6028/nist.ir.88-3883.
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Floyd, Webster, Kyle Dunsford, Andrew Groeneveld, and Kyle Klaus. Finite element, petrographic, and mechanical analyses of field-cored concrete fairlead beam anchor rods from Luke Air Force Base. Engineer Research and Development Center (U.S.), 2024. http://dx.doi.org/10.21079/11681/48591.
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The fairlead beam is used to accomplish installation of the Barrier Arresting Kit 12 energy absorber for setback aircraft arresting system (AAS) installations at permanent operating facilities. Typical fairlead beams are affixed to a Portland cement concrete (PCC) foundation pad by a series of anchor assemblies made up of steel anchor rods set in grout inside galvanized pipe sleeves. US Air Force Civil Engineering Center (AFCEC) subject matter experts have identified a pattern of premature failures in these steel anchor assemblies when they are nondestructively inspected during AAS overhauls. The US Army Engineer Research and Development Center was tasked by AFCEC to investigate potential reasons for these premature failures. This report outlines methods and results of a finite element analysis of the anchorage, a visual and petrographic analysis of field-cored PCC anchor rods from Luke Air Force Base, and a mechanical analysis of specimens taken from the anchor rods within the PCC cores. Multiple modes of PCC distress were observed, and corrosion was evident in and around the anchor assemblies. Mechanical testing of specimens from the anchor rods indicated that an inferior grade of steel was used to fabricate these particular assemblies. Finally, observed deviations from design intention are discussed.
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Rupke, Andrew, Stephanie E. Mills, Michael D. Vanden Berg, and Taylor Boden. Utah Mining - 2023 Metals, Industrial Minerals, Uranium, Coal, and Unconventional Fuels. Utah Geological Survey, 2024. http://dx.doi.org/10.34191/c-138.
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2023 Utah Mining Industry Summary The estimated combined value of Utah’s extractive resource production in 2023 totaled approximately $10.1 billion, including production of metals and industrial minerals ($4.0 billion), natural gas and natural gas liquids ($2.1 billion), crude oil ($3.8 billion), and coal ($314 million) (Figure 1). Utah’s diverse mining industry (metals, industrial minerals, and coal) accounted for $4.3 billion (42%) of total extractive resource production, a significant decrease of $531 million from the 2022 revised value (nominal dollars) and lower than peak values reached in 2011 ($5.3 billion, nominal dollars). Mining activities in Utah currently produce base metals, precious metals, industrial minerals, and coal (Figure 2). Base metal production contributed $1.9 billion and included copper, beryllium, molybdenum, and iron (Figure 3). Notably, copper alone accounted for 65% ($1.4 billion) of Utah’s metal production value. Precious metals produced in Utah include gold and silver, and 2023 production was valued at $250 million (Figure 3). Precious metal production value decreased 19% from 2022 to 2023, primarily due to less gold production, and base metal value decreased 16%, primarily due to less copper production. Industrial minerals produced in Utah include sand and gravel, crushed stone, salt, potash, cement, lime, phosphate, lithium, uintaite (Gilsonite®), clay, gypsum, and other commodities (Figure 2). The estimated value of industrial mineral production in 2023 was $1.9 billion (Figure 3), a 4.2% increase over the revised 2022 estimate. The most valuable industrial mineral group in 2023, estimated at $570 million, was construction material commodity group which includes sand and gravel, crushed stone, and dimension stone. The value of Utah coal production decreased 39% in 2023 to $314 million; production was much lower in 2023, and the average price also decreased (Figure 3). Notably, Utah is the only state to produce beryllium concentrate, potassium sulfate, and uintaite (Gilsonite®); of these commodities, beryllium, was included in the U.S. Geological Survey’s (USGS) 2022 list of critical minerals (U.S. Geological Survey, 2022). Lithium, also considered a critical mineral, has been produced in Utah since 2020, making Utah one of only two lithium-producing states. Throughout this report, production is designated in US short tons (t) or million short tons (Mt) unless otherwise indicated.
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Precios de la Energía y Competitividad Industrial. Universidad de Deusto, 2016. http://dx.doi.org/10.18543/more2064.
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Este estudio detalla los distintos componentes de costes, los diferentes tipos de energía (electricidad, gas u otros combustibles) y examina, los elementos, que los autores consideran relevantes para la competitividad industrial. El análisis se estructura en un esquema con forma de triángulo, en cuya cúspide está la competitividad, y que se sustenta en tres grandes bloques: la productividad, la innovación y el tamaño, elementos todos ellos importantes junto con la dirección estratégica. Con la finalidad de obtener un buen entendimiento de la relevancia y la repercusión que tiene la energía en la competitividad industrial, el estudio desciende al nivel de los subsectores, y así se estudian la siderurgia y la fabricación de tubos, el vidrio y el cemento, el papel, la madera, la química y el caucho, en base a fuentes de datos públicos, lo que ha permitido analizar y profundizar en numerosas variables y ratios. En cuanto a la estructura del trabajo, este contempla dos grandes bloques. En el primero, se pasa revista a la evolución de los precios energéticos y se determinan los sectores más intensivos en energía, de acuerdo con un conjunto de ratios y valores, para un amplio periodo temporal. En este mismo bloque, se pasa revista a la diferencia entre ventajas comparativas y competitivas, lo que da lugar al esquema de análisis de competitividad, ya citado en el que los componentes de innovación, productividad, tamaño y dirección estratégica, se consideran claves. En la segunda parte del estudio, se examina uno a uno y con detalle todos los sectores citados.