Articoli di riviste: "Limestone addition"

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Gołaszewski, J., G. Cygan e M. Gołaszewska. "Analysis of the Effect of Various Types of Limestone as a Main Constituent of Cement on the Chosen Properties of Cement Pastes and Mortars". Archives of Civil Engineering 65, n. 3 (1 settembre 2019): 75–86. http://dx.doi.org/10.2478/ace-2019-0035.

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AbstractThe article is an attempt to compare the impact of the use of various types of limestone as the main constituent of cement on selected mortar properties. Four different limestones were added in amount of 15, 30, 40% to CEM I 42.5 R to obtain limestone cemens. Rheological properties (yield stress, plastic viscosity) of fresh mortar, tensile and compressive mortar strength, early shrinkage, and drying shrinkage were tested. Obtained results indicate that both tensile and compressive strength decreases with the increase of the limestone content in cement. Limestone can worsen or improve workability, depending on distribution of limestone grains. The addition of limestone increases the early shrinkage, but reduces the shrinkage after 28 days. Studies show that the granulation of limestone plays an important role in determining the influence of limestone on mortar properties.

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Chen, Chun Tao, Jiang Jhy Chang, Wei Chung Yeih e Shun Ting Chang. "Sustainable Performance of Limestone Cement". Advanced Materials Research 476-478 (febbraio 2012): 1692–96. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.1692.

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This study explores the effects of the limestone addition on the mechanical properties and durability of the cement. Portions of the Portland cements were replaced by the limestone powders. Results showed that the compressive strengths of the mortar were reduced by the limestone addition. In general, the addition of limestone helps to reduce the shrinkage and improve the sulfate attack resistance. The lowest sulfate-expansion occurred at the specimens with a limestone addition of 10%. Moreover, with additions of 10% or less, the reductions in strength were likely recovered by the addition of fly ash.

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Elgalhud, Abdurrahman A., Ravindra K. Dhir e Gurmel Ghataora. "Limestone addition effects on concrete porosity". Cement and Concrete Composites 72 (settembre 2016): 222–34. http://dx.doi.org/10.1016/j.cemconcomp.2016.06.006.

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Wasis, Basuki, e Eranissa Islamika. "Pengaruh Penambahan Arang Tempurung Kelapa dan Bokashi Pupuk Kandang Terhadap Pertumbuhan Semai Akasia (Acacia Mangium Willd.) di Media Bekas Tambang Kapur". Journal of Tropical Silviculture 10, n. 1 (14 agosto 2019): 29–34. http://dx.doi.org/10.29244/j-siltrop.10.1.29-34.

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Continuous mining activities of limestone operation may cause negative impact such as environmental damage and reduction of soil quality (physically, chemistry, or biological). Revegetation is the process to increasing productivity of postmining limestose land. Acacia mangium is one of fast growing species that can grow in marginal land, symbitotic with rhizobium bacteria, and high economic value. The purpose of this research are to test the response of coconut shell charcoal and cow feces (bokashi) addition to the growth of akasia (Acacia mangium) seedling on postmining limestone soil and to find out the optimum dose of coconut shell charcoal and cow feces (bokashi) addition. This research used a complete randomized design factorial with two factors, each factor have four degree. First factor is addition of coconut shell charcoal and second factors is addition of cow feces (bokashi). The result of this research showed that coconut shell charcoal and cow feces (bokashi) addition on postmining limestone soil gives positive influence towards the amount of root nodule. But not affect other parameters such as height, diameter, total wet weight, total dry weight, and root tops ratio. The interaction between addition 10 g of coconut shell charcoal and 20 g of cow feces (bokashi) is the best composition for a significant effect in improving the amount of root nodule of A. mangium seedling by 78.58%. Very high levels of Ca in the soil medium will be toxic to the acacia plant.Keywords: Acacia mangium, bokashi cow feces, coconut shell charcoal, limestone mining

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Elgalhud, Abdurrahman A., Ravindra K. Dhir e Gurmel S. Ghataora. "Carbonation resistance of concrete: limestone addition effect". Magazine of Concrete Research 69, n. 2 (gennaio 2017): 84–106. http://dx.doi.org/10.1680/jmacr.16.00371.

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Elgalhud, Abdurrahman A., Ravindra K. Dhir e Gurmel Ghataora. "Chloride ingress in concrete: limestone addition effects". Magazine of Concrete Research 70, n. 6 (marzo 2018): 292–313. http://dx.doi.org/10.1680/jmacr.17.00177.

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Jensen, Anker, Jan Erik Johnsson e Kim Dam-Johansen. "Nitrogen chemistry in FBC with limestone addition". Symposium (International) on Combustion 26, n. 2 (1996): 3335–42. http://dx.doi.org/10.1016/s0082-0784(96)80181-0.

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Danny, Gunaran, Nasus K. Y., Josep P. F. Napitupulu e Amelia Makmur. "The Influence of Limestone And Calcium Hydroxide Addition in Asphalt Concrete Mixture". ComTech: Computer, Mathematics and Engineering Applications 7, n. 2 (1 giugno 2016): 83. http://dx.doi.org/10.21512/comtech.v7i2.2242.

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As time passes, flood often occurs in the area of Gunung Sahari, Jakarta Utara. The flood damages concrete asphalt mixture and it needs particular improvement. Therefore, the purpose of this research is to know the effects of the added combination of limestone and calcium hydroxide on concrete asphalt mixture as a filler resistant to flood. Concrete asphalt mixture that filled with the combination of limestone and calcium hydroxide is a mixture that is made with non-uniform aggregat gradations, filler and liquid asphalt mixed and solidified in a heat state. Limestone and calcium hydroxide mixture is used because both materials included in the most numerous sedimentary rock. Concrete asphalt mixture with the filler combination of limestone and calciumhydroxide is made with optimum asphalt 5.4%, one variation level of limestone (15%), and calcium hydroxide (15%), and three variation levels of fillers (5%, 7.5%, and 15%) to get optimum asphalt levels and filler levels that are compatible with flood condition. Based on optimum asphalt 5.4% towards aggregate total weight and combined level of limestone and calcium hydroxide suitable for the conditions, 8.75 % towards fine aggregate weight. The characteristic value of limestone and calcium hydroxide mixture in maximum condition is VIM 4.55%, VMA 18.83%, stability 1031.26 kg and flow 4.93 mm, where the characteristic value meets the established specifications standard by Pekerjaan Umum Bina Marga. From the result, it is showed that the use of the mixture can decrease the value of stability and increase the value of flow, compared with asphalt and filler with normal levels.

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Thalmaier, Gyorgy, Nicoleta Cobȋrzan, Anca-Andreea Balog, Horia Constantinescu, Andrei Ceclan, Mirela Voinea e Traian Florin Marinca. "Assessment of Limestone Waste Addition for Fired Clay Bricks". Materials 15, n. 12 (16 giugno 2022): 4263. http://dx.doi.org/10.3390/ma15124263.

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Our aim was to investigate the feasibility of using limestone waste resulting from stone processing for the manufacturing of fired clay bricks. Waste materials were considered as a partial replacement for clays to reduce the exploitation of natural resources and as a response to the climate neutrality commitments. The samples were prepared to have a waste content of up to 15% and were fired at a temperature of 900 °C. The chemical and mineralogical composition and the physical analysis of raw materials were investigated by using SEM–EDS and XRD diffraction. The result showed an increase in CaO in the clay mixture due to the presence of limestone, which reduced the shrinkage of the products’ compressive strength, up to 55% for samples with a higher content of limestone (15 wt.%), and influenced the samples’ color by making them lighter than the reference sample.

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Ahmad, Muhammad, Muhammad Sajjad, Irfan Khan, Amina Durrani, Ali Durrani, Saeed Gul e Asmat Ullah. "Sustainable production of blended cement in Pakistan through addition of natural pozzolana". Chemical Industry and Chemical Engineering Quarterly 22, n. 1 (2016): 41–45. http://dx.doi.org/10.2298/ciceq141012017a.

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In this work pozzolana deposits of district Swabi, Pakistan were investigated for partial substitution of Portland cement along with limestone filler. The cement samples were mixed in different proportions and tested for compressive strength at 7 and 28 days. The strength activity index (SAI) for 10 % pozzolana, and 5% limestone blend at 7 and 28 days was 75.5% and 85.0% satisfying the minimum SAI limit of ASTM C618. Twenty two percents natural pozzolana and five percents limestone were interground with clinker and gypsum in a laboratory ball mill to compare the power consumption with ordinary Portland cement (OPC) (95% clinker and 5% gypsum). The ternary blended cement took less time to reach to the same fineness level as OPC due to soft pozzolana and high grade lime stone indicating that intergrinding may reduce overall power consumption. Blended cement production using natural pozzolana and limestone may reduce the energy consumption and green house gas emissions.

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Sawicz, Z., e S. S. Heng. "Durability of concrete with addition of limestone powder". Magazine of Concrete Research 48, n. 175 (giugno 1996): 131–37. http://dx.doi.org/10.1680/macr.1996.48.175.131.

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Michalski, Jacek A. "Equilibria in Limestone-Based FGD Process: Magnesium Addition". Industrial & Engineering Chemistry Research 45, n. 6 (marzo 2006): 1945–54. http://dx.doi.org/10.1021/ie050160p.

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Jena, M. S., P. Sahu, P. Dash e J. K. Mohanty. "Beneficiation of limestone plant rejects for value addition". Journal of Hazardous Materials 262 (novembre 2013): 218–27. http://dx.doi.org/10.1016/j.jhazmat.2013.08.048.

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Fahriani, Ferra, Desy Yovianti, Eko Saputra e Merley Misriani. "Perbaikan Subgrade pada Jalan Kampung Keramat di Kota Pangkalpinang dengan Menggunakan Kapur Padam Sebagai Bahan Stabilisasi Tanah". Jurnal Ilmiah Rekayasa Sipil 17, n. 1 (26 aprile 2020): 22–30. http://dx.doi.org/10.30630/jirs.17.1.348.

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Soil is the main support in a construction. Unstable soil conditions, especially in the subgrade can cause damage to the road. Based on the results of a direct survey in the field, it was found that the condition of the Jalan Kampung Keramat in Pangkalpinang City was damaged. This might be caused by the condition of the subgrade on the road which is unstable and the subgrade is categorised as clay soil type. This study aims to improve the subgrade on Jalan Kampung Keramat in Pangkalpinang City by using limestone as a soil stabilization material. This study used an experimental method in the laboratory by making mixture between clay soil and limestone with four different variations in the percentage of limestone, namely 0%, 3%, 5%, 7%. There are four parameters of the mixed characteristics that are tested and analysed, namely: the Atterberg limit, specific gravity, soil gradation and CBR value. The results show that the Atterberg limit values (liquid limit-LL and plasticity index-IP) and specific gravity tend to decrease with increasing percentage of limestone extinguished. However, the plastic limit value (PL) shows the opposite tendency, i.e. it increases with the decreasing percentage of limestone. The specific gravity values obtained based on the percentage of lime outages (0%, 3%, 5%, 7%) are 2.63, 2.61, 2.60, and 2.58, respectively. In addition, the addition of limestone causes changes in soil gradation, namely the addition of retained fraction # No.200 and the reduction of passed fraction # No.200. The Addition of limestone can increase the CBR value of the soil, where the addition of 7% of limestone produces the highest CBR value (21.3%) compared to 5% limestone (15.7%), 3% limestone (13.4%) and 0% limestone (11.2%). Therefore, using limestone can improve quality of subgrade, which can be seen from the value of CBR obtained.

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Abdelhamid, Marzouk Mohamed Aly, B. G. Mousa, Hassan Waqas, Mohamed Abdelghany Elkotb, Sayed M. Eldin, Iqra Munir, Rashid Ali e Ahmed M. Galal. "Artificial Thermal Quenching and Salt Crystallization Weathering Processes for the Assessment of Long-Term Degradation Characteristics of Some Sedimentary Rocks, Egypt". Minerals 12, n. 11 (31 ottobre 2022): 1393. http://dx.doi.org/10.3390/min12111393.

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This research aims at investigating the deterioration of limestone rocks due to the influences of thermal quenching and salt crystallization weathering tests and predicting their long-term durability. Therefore, six types of limestones were quarried from different provinces of Egypt and subjected to 50 cycles of thermal quenching and 25 cycles of salt crystallization weathering processes. The porosity, Schmidt hammer rebound hardness, ultrasound pulse velocity, Brazilian tensile strength, and uniaxial compression strength were determined before and after weathering processes. In addition, the mathematical decay function model was developed to evaluate the degradation rate of samples against weathering processes. Results proved that the cyclic salt crystallization deteriorates the physico-mechanical characteristics of the studied limestone more strongly than the thermal quenching cycles do. The decay constant and half-life indexes obtained here indicate that the degradation rate differs for various limestone specimens under thermal and salt weathering processes. This model also showed that the deterioration rate of the studied rocks was higher during cyclic salt crystallization in comparison with thermal quenching. Therefore, the rock degradation rate and or long-term durability under cyclic thermal and salt processes can be estimated accurately. These results show that the studied limestones can be used as building stones in regions exposed to frequent cyclic thermal and salty weathering conditions for long periods without degradation. However, partial attention should be given to LSG limestone rocks characterized by increased porosity and water absorption characteristics.

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Babor, Dănuţ-Traian, Marius George Butnariu e Dorina Nicolina Isopescu. "The Permeability Analysis in Case of Tuff and Limestone Addition in the Concrete Composition". Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section 67, n. 3 (18 luglio 2022): 61–68. http://dx.doi.org/10.2478/bipca-2021-0025.

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Abstract This research aimed to analyze the effects of using tuff and limestone as supplementary pozzolanic materials on the permeability of a classic C12/15 concrete composition. There were designed two types of concrete compositions with different degrees of permeability, namely P8 10 and P12 10 as reference concrete compositions and eight experimental concrete compositions with tuff in 6% and 10% of the cement quantity and with limestone in the same proportions. According to results, the tuff and limestone led to the decrease of concrete permeability, the best values being registered in the case of using 10% tuff in the concrete composition with P8 10 class of permeability.

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Zhang, Wan Peng, Mei Yan Wang, Xiu Qin Ma, Chao Huang, Fang Chen e Cheng Liang Jia. "Experimental Study on Reactivity of Limestone in FGD System". Advanced Materials Research 875-877 (febbraio 2014): 1702–6. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.1702.

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The limestone collected from the Ji county of Tianjin was investigated in this study. The characterization of the limestone dissolution in wet FGD system is carried out by sulfuric acid titration. The results indicate that A lower PH value is benefit for the limestone dissolution, which causes high dissolution rate within short time. Smaller particle size results in higher dissolution rate. The addition of inorganic salt and organic acid significantly affect the limestone dissolution. The limestone dissolution rate increases with the increase of organic acid concentration. In all the inorganic salt, it is obvious that Na+ has an positive effect while CI- plays a negative role on the limestone dissolution. However, the addition of composite additive of adipic acid plus MgO to the limestone slurry is greatly better than using the adipic acid or MgO only.

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Belikov, I. P., G. E. Isaenko, G. A. Nechkin e V. A. Kobelev. "Application of manganous limestone as a fluxing addition at pellets production". Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information, n. 12 (19 dicembre 2018): 27–32. http://dx.doi.org/10.32339/0135-5910-2018-12-27-32.

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Usage of non-fluxed pellets in blast furnaces results in blocking of hearth coke filling, decreasing of blast furnaces productivity and increasing of coke rate. The wide range of plastic-viscous state and non-sufficient filterability of pellets slag portion through the coke filling are the main reasons of the consequences. Fluxed pellets have narrower interval of plastic-viscous state and better filterability of pellets slag portion through the coke filling. Their utilization enables to decrease the gas-dynamic resistance of blast furnace cohesion zone, to eliminate progressive hearth blocking, to intensify the hot metal production process and to increase its economic efficiency. In 70–80thof the previous century attempts were made to substitute the bentonite in burden at pellets production by hydrated lime and burnt lime, by marl, by nontronite clay, by red sludge and other additives, combining properties of the raw pellets strengthening and fluxing. But the methods listed were not implemented practically, in particular, because of difficulties in those two properties effective combining. Last years a new raw material appeared at the fluxes market – the manganous limestone. Manganese oxide, contained in it, decreases the sinter smelting temperature, calcium carbonate acts as a flux, while water and physical properties of the limestone improve the increase of the burden lump-forming capacity and sinter strength. The aim of the study was to check the manganous limestone influence on the production process and raw pellets strength, change of roasting parameters and strength of roasted pellets, as well as change of high-temperature properties of fluxed pellets made of Stojlensky GOK concentrates. The study were carried out in laboratory conditions by usage of Dash-Salakhlin bentonite and manganous limestone. The results of laboratory study of both raw and roasted pellets, obtained at utilization of manganous limestone as a fluxing additive to burden, showed, that their physical and mechanical properties are higher and metallurgical properties are higher, compared with non-fluxed pellets.

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Stewart, Michael C., Vasilije Manovic, Edward J. Anthony e Arturo Macchi. "Enhancement of Indirect Sulphation of Limestone by Steam Addition". Environmental Science & Technology 44, n. 22 (15 novembre 2010): 8781–86. http://dx.doi.org/10.1021/es1021153.

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Mohamed, Ashraf Ragab, Mona Elsalamawy e Marwa Ragab. "Modeling the influence of limestone addition on cement hydration". Alexandria Engineering Journal 54, n. 1 (marzo 2015): 1–5. http://dx.doi.org/10.1016/j.aej.2014.11.004.

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Chen, Chuanmin, Ye Zhuang e Chunbo Wang. "Enhancement of direct sulfation of limestone by Na2CO3 addition". Fuel Processing Technology 90, n. 7-8 (luglio 2009): 889–94. http://dx.doi.org/10.1016/j.fuproc.2009.04.008.

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Al-Mansoor, Ameen, Rafee Al-Hamidi e Omar Al-Badrani. "Sedimentary Environments and Age Determination of the Chia Gara Formation, Northern Iraq". Iraqi Geological Journal 56, n. 1B (28 febbraio 2023): 64–79. http://dx.doi.org/10.46717/igj.56.1b.6ms-2023-2-14.

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The rock successions of the Chia Gara Formation were studied at two surface sections (Barsarin and Rania) from North-Eastern Iraq. The detailed sedimentological study reveals that the formation consists basically of thin-bedded black limestone, dolomitic limestone, marly limestone, bituminous shales, and Ammonitic limestone. The petrography results showed that the formation consists of various petrographic components as Ammonites, calcispheres, radiolarian, and silicate sponges in addition to the groundmass of micrite. Ammonite taxa are examined in the upper part of the Chia Gara Formation to find Ammonite species, of which seven species have been identified. One biozone is postulated based on the above assemblages, in order of age: Berriasella Jacobi, from a regional perspective, this biozone was connected with other Ammonite assemblages, leading to the conclusion that the Formation age is Early Cretaceous in age. The facies analysis demonstrates that the rock succession consists mainly of three microfacies. The main microfacies include lime mudstone, wackestone, and packstone. At the same time, the lithofacies comprise limestones and shales. The overall characteristics of these facies show that the Chia Gara Formation was deposited in three different environments; (1) the Lower part of the Upper bathyal (2) the Middle part of the bathyal, and (3) the Upper part of the outer shelf environment.

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Rushafarani, Yurida, Sumiati e Nahrowi. "Kecernaan Kalsium dan Fosfor, pH gizzard, Kadar Air Ekskreta dan Digesta pada Ayam Petelur yang Diberi Ukuran Partikel Batu Kapur Berbeda dan Enzim Fitase". Jurnal Ilmu Nutrisi dan Teknologi Pakan 21, n. 2 (31 agosto 2023): 130–36. http://dx.doi.org/10.29244/jintp.21.2.130-136.

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This study aimed to determine the coefficient of total calcium and phosphorus digestibility effects from limestone as a source of calcium and the effect of phytase enzymes on laying hens. This study used 180 Hy-line Brown laying hens aged 75 weeks. The experimental design used was a 2x2 factorial complete randomized design (CRD) with 9 replications. The first factor was limestone particle size, i.e., P1 = limestone flour and P2 = limestone granules, and the second factor was phytase enzyme dose, i.e., Q1 = 0 FTU and Q2 = 1000 FTU. The observed variables were gizzard pH, excreta moisture content (MC), digesta MC, calcium and phosphorus digestibility using two samples and ileal digestibility. The results showed that the digestibility of calcium from limestone flour was significantly different compared to limestone granules at P<0.05. The phytase addition and the interaction with limestone particle size did not affect gizzard pH, total and ileal digestibility of calcium and phosphorus. Excreta and digesta MC had a significant effect on the particle size of limestone, the highest MC was limestone granules compared to flour (P<0.001). The addition of phytase had an effect on reducing excreta MC (P< 0.001). There was interaction between limestone size and phytase in excreta and digesta MC. The conclusion of the research was that laying hens were more efficient in digesting calcium from limestone flour compared to limestone granules. Phytase could reduce excreta and digesta MC. Key words: calcium, digestibility, limestone, particle size, phytase

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Liu, Hemin, Qian Huang e Liang Zhao. "Deterioration of concrete containing limestone powder exposed to sulfate attack at ambient temperature". Materials Express 11, n. 5 (1 maggio 2021): 724–31. http://dx.doi.org/10.1166/mex.2021.1963.

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This study investigates the deterioration of concrete containing limestone powder exposed to sulfate solution under ambient temperature (20~25 °C). Microstructure and mineral phases within the attacked concrete were measured by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). It was found that the addition of limestone powder increased the initial porosity of concrete. Consequently, a larger amount of SO2–4 ions diffused into the concrete containing limestone powder, and their degree of deterioration caused by sulfate attack increased with the increase in limestone powder content. At ambient temperature, gypsum and ettringite were the major attack products, respectively within the surface and nearsurface portions of concrete containing limestone powder, which was consistent with the products of sulfate attack within concrete without limestone powder. Therefore, the type and distribution of the attack products in concrete had not been revised due to the addition of limestone powder. Nevertheless, the adverse influence of limestone powder on the sulfate resistance of concrete, even at ambient temperature, should be considered. Furthermore, effective measures should be implemented to improve the durability of concrete containing limestone powder in this environment.

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Velayudhan, Deepak E., Arun Kumar e Yueming Dersjant-Li. "63 Effect of a Novel Consensus Bacterial 6-phytase Variant on Mineral Digestibility and Bone Ash in Young Growing Pigs Fed Diets with Low and High Soluble Limestone". Journal of Animal Science 99, Supplement_1 (1 maggio 2021): 42–43. http://dx.doi.org/10.1093/jas/skab054.075.

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Abstract The effect of a novel consensus bacterial 6-phytase variant (PhyG) on total tract digestibility (ATTD) of minerals and bone ash was evaluated in piglets fed diets with low and high soluble limestone (LSLM and HSLM, 69 and 92% solubility at 5 min). For each limestone, 8 diets were formulated: an inorganic phosphate-free negative control (NC) diet based on wheat, corn, soybean-meal, canola-meal and rice-barn [0.18% standardized total tract digestible (STTD) P and 0.58% Ca], NC supplemented with 250, 500, 1,000 or 2,000 FTU/kg of PhyG, or with monocalcium phosphate (MCP) to formulate 3 positive controls with 0.21, 0.27, 0.33% STTD P, and 0.64, 0.70 and 0.75% Ca, respectively. In total 128 pigs (12.8 ± 1.33 kg, n=8) were adapted for 14 d followed by 4 d of fecal collection. Femurs were collected on the last day. Data were analyzed as one-way ANOVA and means separated by Tukey test. In addition, a 2 × 4 factorial analysis was performed to test the effect of limestone solubility at different MCP levels in control diets, a 2 × 5 factorial analysis was performed to determine the effect of limestone solubility at different phytase levels. Phytase dose-response was analyzed by orthogonal polynomial. Across phytase diets, HSLM reduced (P < 0.05) ATTD Ca and P compared with LSLM. A consistent negative effect on ATTD P was also observed with HSLM in control diets. Across limestones, increasing phytase increased (P < 0.05) ATTD Ca and P in a linear or exponential manner. Limestone solubility had no impact (P = 0.69) on bone ash. PhyG linearly increased (P < 0.05) bone ash and 250 FTU/kg of PhyG maintained bone ash compared to PC. In conclusion, limestone solubility showed a negative impact on ATTD P and Ca, the novel consensus phytase improved ATTD P and Ca regardless of limestone.

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Lairaksa, Nirut, e Tony Moon. "Use of CRT Funnel Glass as a Fine Aggregate in Self-Compacting Mortar: The Effect of Limestone on Pb Immobilization". Applied Mechanics and Materials 193-194 (agosto 2012): 513–16. http://dx.doi.org/10.4028/www.scientific.net/amm.193-194.513.

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End-of-life CRTs are classified as hazardous waste since the funnel glass component has a high Pb content. Alternative management of the glass is required due to the cessation of closed-loop recycling of CRT glass. This study aims to compare the feasibility of using CRT funnel glass as fine aggregates in a self-compacting mortar by addition of limestone to enhance the Pb immobilization. Sample mixtures of self-compacting mortar were prepared from Ordinary Portland cement Type 1 (OPC) with water/cementitious (W/C) ratio of 0.38 by weight, which contained 0, 20 and 40 wt% of Samsung CRT funnel glass ground to sizes smaller than 595 µm as a sand replacement. The sample with glass mixtures contained additions of 5, 10 and 15 wt% of limestone, ground to sizes smaller than 297 µm as a viscosity modifying agent (VMA). The samples’ flow ability was tested by V-funnel and Marsh cone. Pb-fixation in the samples was analysed by TCLP at 7 days and 14 days. The addition of limestone as a viscosity modifying agent improved flow ability in mixtures with CRT funnel glass, with the addition of 10 wt% limestone showing the highest flow improvement in V-funnel tests for both glass mixtures. CRT funnel glass utilized as sand replacement at 20 and 40 wt% showed Pb leaching results within the US EPA allowable limits. However, the addition of limestone reduced the Pb immobilization ability in mortars. A silica based VMA such as fly ash and rice husk ash should be used for these applications.

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Liu, Juan Hong, Shao Min Song, Yong Mei Sun e Lin Wang. "Influence of Ultrafine Limestone Powder on the Performance of High Volume Mineral Admixture Reactive Powder Concrete". Advanced Materials Research 152-153 (ottobre 2010): 1583–86. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.1583.

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The effects of ground limestone powder on the fluidity, strength and viscosity of reactive powder concrete(RPC) were studied. The results show that, the flexural strength of RPC greatly increases with the increase of the content of ground limestone powder at the W/B of 0.16, 0.18 and 0.20 when ground limestone powder content is less than 30%; for fresh RPC, the maximum compressive strength is 160MPa and the maximum flexural strength is 36.9MPa when the limestone powder content is 158kg/m3 at the W/B of 0.20, with 20cm good fluidity and very compact microstructure; the viscosity of RPC greatly decreases with the addition amount of ground limestone powder, the viscosity of RPC mixture changes from 60,000MPa•S to 18,000MPa•S when cement content decreases from 388kg/m3 to 150kg/m3 and the addition amount of limestone powder increases from 0 to 238kg/m3.

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Cózar, Pedro, e Ian D. Somerville. "The Carboniferous Archerbeck Borehole, near Canonbie (Dumfriesshire, southern Scotland): biostratigraphic revision of the late Asbian to early Pendleian succession using foraminiferans and regional correlations". Earth and Environmental Science Transactions of the Royal Society of Edinburgh 103, n. 1 (marzo 2012): 105–22. http://dx.doi.org/10.1017/s1755691012000060.

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ABSTRACTThe upper half of the Archerbeck Borehole contains a continuous Mississippian succession from the late Asbian (late Viséan) to the Pendleian (early Serpukhovian), with numerous limestone horizons. The borehole sequence lies within the Solway Basin (western end of the Northumberland Trough) and bridges the successions between the Midland Valley of Scotland and the Pennines (northern England). The rich foraminiferal and algal assemblages are compared to those described by previous authors, and genera as well as species are updated as far as is possible. In addition, some other overlooked or underestimated taxa have been identified and illustrated, which improve notably the biostratigraphic resolution of the Archerbeck Borehole succession. Within the abundant foraminiferal assemblages can be highlighted the richness and diversity of representatives of the family Archaediscidae. In general, the succession developed in the Archerbeck Borehole is closely comparable with that in the Alston Block of northern England. The Asbian/Brigantian transition mimics that observed in the Janny Wood boundary stratotype section, with clear late Asbian horizons (lower part of the Archerbeck Beds), transitional beds (middle and upper parts of the Archerbeck Beds), and Brigantian limestones (from the Cornet Limestone upwards). The base of the early Brigantian is placed at the base of the Cornet Limestone (equivalent to the Lower Peghorn Limestone in the Alston Block). The base of the late Brigantian is placed at the base of the Gastropod Limestone (equivalent to the Scar Limestone Member in northern England), and the base of the Pendleian is repositioned at the base of the Under Limestone (equivalent to the Four Fathom Limestone Member in northern England). Throughout, the borehole, protista and microfloral elements are abundant, which allows the recognition of Assemblages 4 to 10, previously recognised in northern England and the Midland Valley of Scotland. Furthermore, other local assemblages are recognised and related to palaeoecological controls, although they do not represent any improvement in biostratigraphical resolution.

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29

Hassan, Kawther A., Mohanad H. Al-Jaberi e Liqaa N. Salim. "Depositional Properties of the Middle Miocene Fatha Formation, in K Oilfield, Southern Iraq". Iraqi Geological Journal 55, n. 2B (31 agosto 2022): 139–52. http://dx.doi.org/10.46717/igj.55.2b.12ms-2022-08-28.

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The Fatha Formation, formerly known as the Lower Fars Formation, was deposited in a shallow basin, southern Iraq during the Middle Miocene. By using the description of the cores, we found large heterogeneity in the lithology; contains a mixing of limestones, mudstone, marl, marly limestone, sandstone, and gypsum, or anhydrite. In this study, the Fatha Formation was divided into three main units according to lithofacies, namely, marl, marl-anhydrite, and limestone, in addition to, the presence of thin evaporitic and sandstone layers along with the formation but thicker with marl. X-ray diffraction and SEM tests which are accurate methods to identify the mineralogy enable inference of a high percent of the dolomite, calcite, and anhydrite; this may be attributed to the formation environment, In addition to the presence of some clay minerals such as illite and palygorskite. The petrographic details, microfacies analysis, and depositional environment studies led to recognition of four main microfacies including mudstone, wackestone, packstone, and grainstone; and nine sub microfacies were deposited in a shallow part of the inner ramp at three zones: peritidal, lagoon, and shoal.

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Hang, Mei Yan, Meng Gao e Ying Jing Lan. "Study on the Influence of Limestone Dust on Performance of Cement Mortar". Applied Mechanics and Materials 368-370 (agosto 2013): 992–96. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.992.

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This paper use dust particles which is produced by crushing limestone to replace the same amount of cement in different proportions, study the performance of cement mortar, and determine the best dosage of limestone dust. Its size is less than 0.08mm. The result shows that limestone dust has water-reduce effect and does not reduce the strength of the mortar when the dosage of limestone dust is less than 12%. Meanwhile the addition of limestone powder can improve the shrinkage property and the durability of sulfate. It explains that limestone dust has a certain activity, not the inert material.

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31

Gawlick, Hans-Jürgen, Milan Sudar, Divna Jovanovic, Richard Lein, Sigrid Missoni e Ioan Bucur. "From shallow-water carbonate ramp to hemipelagic deep-marine carbonate deposition: Part 1. General characteristics, microfacies and depositional history of the Middle to Late Anisian Bulog sedimentary succession in the Inner Dinarides (SW Serbia)". Annales g?ologiques de la Peninsule balkanique, n. 00 (2023): 6. http://dx.doi.org/10.2298/gabp230329006g.

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The opening of the Neo-Tethys started in the Middle Anisian and is recorded in the drowning succession of the shallow-water Ravni/Steinalm Carbonate Ramp and the subsequent deposition of deep-marine limestones, e.g., the red nodular limestones of the Bulog Group and equivalents. In the Inner Dinarides of southwest Serbia the continental break-up of the Neo-Tethys Ocean is characterized by the formation of a horst-and-graben topography. The change from deposition of shallow-water carbonates formed in an epicontinental sea (graben stage of the Neo-Tethys Wilson Cycle) to red nodular deep-marine limestones (Bulog Limestone) in the late Pelsonian (Middle Anisian) is relatively abrupt due to the rapid decrease of carbonate production. The deeper-water Bulog Limestone, deposited in the early stage of the passive continental margin evolution of the western Neo-Tethys can be dated by conodonts and in rare cases also by ammonoids quite exactly, and therefore it is possible to reconstruct the Pelsonian to Illyrian sedimentological evolution precisely: 1) The late Pelsonian is characterized by the drowning of the shallow-water Ravni Carbonate Ramp and a rapid deepening of the depositional realm. Extension led to the formation of neptunian dikes in the shallow-water Ravni Formation, filled with deeper-marine red micrite, and the formation of a horst-and-graben morphology. Whereas some of the horsts uplifted and emerged in the grabens near to the newly formed escarpments thick breccia successions were deposited with a fining-upward trend during the early-middle Illyrian. On top of other horsts, the grabens, or the newly formed gentle slopes red nodular limestones were deposited. In cases layers with enriched ammonoids formed (Fossillagerstatten). 2) The early-middle Illyrian ongoing subsidence resulted in the deposition of more and more condensed red nodular limestones with hardground formation. 3) Around the middle/late Illyrian boundary a new pulse of tectonic motions resulted in the tilting of blocks, the formation of new escarpments and again mobilization of mass transport deposits. In addition, a second generation of neptunian dikes was formed. They crosscut the late Pelsonian to middle Illyrian Bulog Limestone, the Pelsonian Ravni Formation, and the older generation of neptunian dikes in the shallow-water Ravni Formation. All formerly emerged horsts flooded and red nodular limestones were deposited on the karstified shallow-water Ravni Formation after a gap. This second pulse of tectonic motions is related to the widespread volcanism in the Dinarides as visible in the appearance of mm-sized biotite clasts in the late Illyrian Bulog Limestone. In contrast to the Outer Dinarides, where thick volcanics are intercalated in the Illyrian sedimentary succession, in the Bulog Limestone successions of the Inner Dinarides volcanics are missing. In general the Pelsonian-Illyrian sedimentary succession is characterized by a stepwise deepening of the depositional realm.

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32

Anhar, Muh, e Betti Ses Eka Polonia. "The Effect Of Addition Of Limestone Powder And Gypsum As Isolator Media On Low Carbon Steel SMAW Welding". Journal of Applied Engineering and Technological Science (JAETS) 2, n. 2 (9 maggio 2021): 94–102. http://dx.doi.org/10.37385/jaets.v2i2.223.

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Metal connection due to heat with or without the influence of pressure or metallurgical bonds caused by attractive forces between atoms. DIN (Deutsche Industrie Normen) state that metallurgical bonding of metal or guide metal joints in a melted or liquid state. This study aims to determine the effect of limestone powder and gypsum as an insulating medium in SMAW (Shielded metal arc welding) welding. This study using experimental methods with SMAW welding. Welding metal cooled with limestone media has a harder hardness than gypsum and air media, which is limestone has a thermal conductivity value of 3.897 W / mºC. In comparison, gypsum has a thermal conductivity value of 1.39 W/mºC, and air has a thermal conductivity value of 0.023 J/msºC, so limestone is a better insulator than gypsum and air. The greater the conductivity value of the object, the better the thermal conductivity of the metal and the more complicated the weld metal and the lower the thermal conductivity value, the softer the metal hardness, limestone has a thermal conductivity value of 3.897 W / mºC while gypsum has a thermal conductivity value of 1, 39 W / mºC and air have a thermal conductivity value of 0.023 J / msºC, proving that the lower the conductivity value, the hardness of the weld metal is getting softer, but in the HAZ section it proves that the lower the conductivity value, the more complex the hardness in the HAZ section.

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33

Prestes, Nelson Eduardo, Cassandro Vidal Talamini do Amarante, Cassiano Eduardo Pinto, Gabriel Avila Prestes, Guilherme Doneda Zanini, Pablo Giliard Zanella e André Fischer Sbrissia. "Limestone and phosphorus application and forage production in natural pastures with sodseeding of cool-season species". Semina: Ciências Agrárias 38, n. 6 (23 novembre 2017): 3681. http://dx.doi.org/10.5433/1679-0359.2017v38n6p3681.

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Natural pastures are important ecosystems that both contribute to biodiversity conservation and provide an important source of income, especially for cattle ranchers. While these pastures yield fairly low productivity, they can be improved by increasing soil fertility and introducing species with high productive potentials. In this sense, the purpose of this study was to evaluate the effects of applying limestone and phosphorus, as well as introducing cool-season species with a mixture of species dominated by Schizachyrium tenerum Nees, into a natural pasture in the Catarinense Plateau. The experiment was conducted from January 2010 to December 2013; the treatments consisted of superficial distribution of limestone in proportions of 3.6, 7.2, 11.0, and 14.4 t ha-1, as well as distribution of phosphorus in the form of triple superphosphate in proportions of 35, 70, 105, and 140 kg of P2O5 ha-1. In addition, cool-season species were overseeded. The experiment consisted of a randomized block design with subdivided plots and three replications. Limestone was applied to the main parcel, whereas phosphorus was applied to the subplots. There was no interaction between the levels of limestone and phosphorus. The application of 11.0 t ha-1 of limestone yielded the highest forage production, with 3,932.2 kg of dry matter (DM) ha-1 during the second year. Red clover was the species that best reacted to the additions, with levels of 7.2 and 11.0 t ha-1 over the 4 years. In addition, phosphorus provoked a positive response throughout the experiment. The highest forage production was observed during the second year, with an addition of 140 kg P2O5 ha-1 (4,419.4 kg DM ha-1). Only one-eighth of the recommended amount of limestone (3.6 t ha-1) allowed for the establishment and persistence of the legumes introduced into natural pastures. These additions, associated with increasing levels of phosphorus, yielded linear growth in the production of forage in natural pastures with a mixture of species dominated by Schizachyrium tenerum Nees.

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34

Han, Rui, Fei Sun, Jihui Gao, Siyu Wei, Yanlin Su e Yukun Qin. "Trace Na2CO3 Addition to Limestone Inducing High-Capacity SO2 Capture". Environmental Science & Technology 51, n. 21 (19 ottobre 2017): 12692–98. http://dx.doi.org/10.1021/acs.est.7b04141.

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35

Suardi, Enita, Zulfira Mirani, Silvianengsih Silvianengsih, Oni Guspari e Desmon Hamid. "Pemanfaatan Limbah Penambangan Bukit Kapur Untuk Stabilisasi Tanah Lempung ( Clay )". Jurnal Ilmiah Rekayasa Sipil 18, n. 2 (31 ottobre 2021): 167–74. http://dx.doi.org/10.30630/jirs.v18i2.675.

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Soil stabilization by adding new materials is one of the alternatives to soil repair that can improve the properties of the soil, namely by mixing new materials and soil that is then compacted. Waste left over limestone hill mining,among others in the form of materials with various sizes of granules. This study aims to review the effect of the addition of limestone hill mining waste material on the density and value of the California Bearing Ratio (CBR) of clay soil. Tests conducted only on a laboratory scale with variations in the increase in limestone hill mining waste levels are 0%, 5%, 10%, and 15% to the total weight of the mixture. Laboratory CBR testing is performed under optimum water content conditions. The results showed that the stabilization of soft soils using limestone hill mining waste, can increase the density and value of soil CBR. The most optimal level of use of limestone hill mining waste and which provides the highest CBR value is for the addition of 5%of limestone hill mining waste with a CBR value of 26.5%.

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36

Gołaszewska, Małgorzata, e Zbigniew Giergiczny. "Study of the Properties of Blended Cements Containing Various Types of Slag Cements and Limestone Powder". Materials 14, n. 20 (14 ottobre 2021): 6072. http://dx.doi.org/10.3390/ma14206072.

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It is currently vital to use more environmentally friendly cementitious composites, such as blended slag-limestone cements. However, many properties of slag-limestone cements are not yet fully research, especially in regards to the effect of limestone properties on properties of mortars and concrete. In the research, three types of slag cements were mixed with two types of limestone to obtain multi-component slag-limestone cements. Tests of rheological properties, heat of hydration, and compressive strength were conducted to ascertain the effect of limestone on the cement properties and to check the viability of this type of cement for engineering practice. It was found that the addition of up to 10% of limestone to slag cements did not have negative effects on tested properties; however, the exact influence of limestone was dependent on limestone particle size distribution. Increasing the amount of limestone in limestone-slag cements to 15% significantly decreased the compressive strength of the mortars and decreased hydration heat but had no significant effect on rheological properties.

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37

Liu, Hao, Shihong Peng, Ke Zhang, Yuelin Qin, Fei Meng, Wenchao He, Weiqiang Liu, Min Chen e Lixiang Yan. "Effect of Finely Ground Limestone and Dolomite on Compression Strength and Reduction Swelling of Vanadium-Titanium Pellets". Materials 14, n. 16 (7 agosto 2021): 4433. http://dx.doi.org/10.3390/ma14164433.

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Vanadium−titanium magnetite (VTM) is an important raw material for ironmaking under the situation of increasingly demanding scarce resources. To further improve the metallurgical properties of pellets, and to satisfy the requirements of blast furnace slag basicity, finely ground dolomite and limestone have been added to the pellet. In this study, the effect of finely ground dolomite and limestone on the metallurgical properties (green pellet drop strength, cold compression strength, reduction swelling index, and microscopic mineral structure) of VTM pellets were investigated. With the addition of finely ground dolomite and limestone, the drop strength of the green pellet was improved. The effect of adding finely ground limestone was greater than adding finely ground dolomite. Adding more finely ground dolomite and limestone compared to pellets without limestone and dolomite, the cold compression strength was decreased, which was attributed to the decomposition of limestone and dolomite during the induration of pellets. With the addition of dolomite, the reduction swelling index (RSI) increased firstly and then decreased. When the basicity of the pellet was 0.54 to 0.94, the slag phase with the lowest melting point was formed, corresponding to the maximum of the reduction swelling index. For the pellets with added limestone, the reduction swelling of the pellets deteriorated. The reduction index of the pellets increased and reached the maximum (26.6%) at a basicity of 1.54, which belongs to abnormal swelling.

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38

Vázquez-Rodríguez, Francisco, Nora Elizondo, Myriam Montes-González, Cristian Gómez-Rodríguez, Yadira González-Carranza, Ana M. Guzmán e Edén A. Rodríguez. "Microstructural and Mechanical Characteristics of Alkali-Activated Binders Composed of Milled Fly Ash and Granulated Blast Furnace Slag with µ-Limestone Addition". Materials 16, n. 10 (18 maggio 2023): 3818. http://dx.doi.org/10.3390/ma16103818.

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Abstract (sommario):

Concrete is the most used construction material, needing large quantities of Portland cement. Unfortunately, Ordinary Portland Cement production is one of the main generators of CO2, which pollutes the atmosphere. Today, geopolymers are an emerging building material generated by the chemical activity of inorganic molecules without the Portland Cement addition. The most common alternative cementitious agents used in the cement industry are blast-furnace slag and fly ash. In the present work, the effect of 5 wt.% µ-limestone in mixtures of granulated blast-furnace slag and fly ash activated with sodium hydroxide (NaOH) at different concentrations was studied to evaluate the physical properties in the fresh and hardened states. The effect of µ-limestone was explored through XRD, SEM-EDS, atomic absorption, etc. The addition of µ-limestone increased the compressive strength reported values from 20 to 45 MPa at 28 days. It was found by atomic absorption that the CaCO3 of the μ-limestone dissolved in NaOH, precipitating Ca(OH)2 as the reaction product. SEM-EDS analysis showed a chemical interaction between C-A-S-H- and N-A-S-H-type gels with Ca(OH)2, forming (N, C)A-S-H- and C-(N)-A-S-H-type gels, improving mechanical performance and microstructural properties. The addition of μ-limestone appeared like a promising and cheap alternative for enhancing the properties of low-molarity alkaline cement since it helped exceed the 20 MPa strength recommended by current regulations for conventional cement.

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39

Setia Febriatna, Triya, Prihadi Setyo Darmanto e Firman Bagja Juangsa. "Experimental analysis on calcination and carbonation process in calcium looping for CO2 capture: study case of cement plants in Indonesia". Clean Energy 7, n. 2 (28 marzo 2023): 313–27. http://dx.doi.org/10.1093/ce/zkac072.

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Abstract (sommario):

Abstract Carbon dioxide (CO2) is the main contributor to greenhouse gases that affect global warming. The industrial sector is the third largest producer of CO2 and the cement industry is one of the industries that consistently produces the most significant CO2 emissions. The cement industry produces 5–8% of global CO2 emissions. Several methods for reducing specific CO2 emissions have been reported in the cement industry, including calcium looping, which uses the reversible reaction between calcination [calcium carbonate (CaCO3) decomposition] and carbonation [CO2 capture by calcium oxide (CaO)]. This work investigates calcium looping employing limestone obtained directly from several cement factories in Indonesia to observe the carbon-absorption characteristics of limestone from different mining locations. The experiment was carried out using a tube furnace equipped with a controlled atmospheric condition that functions as a calciner and a carbonator. X-ray diffraction and scanning electron microscopy with energy-dispersive x-ray spectroscopy characterization were conducted to analyse the changes in the experimental samples. The results demonstrated that the reactor configuration was capable of performing the calcination process, which converted CaCO3 to calcium hydroxide [Ca(OH)2], as well as the carbonation process, which captured carbon and converted it back to CaCO3. Parametric analysis was performed on both reactions, including pressure, temperature, duration, particle size and reaction atmosphere. The results show that the limestone obtained from all sites can be used as the sorbents for the calcium-looping process with an average reactivity of 59.01%. Limestone from cement plants in various parts of Indonesia has the potential to be used as carbon sorbents in calcium-looping technology. With a similar CO2 concentration as the flue gas of 16.67%, the experimental results show that Bayah limestone has the maximum reactivity, as shown by the highest carbon-content addition of 12.15 wt% and has the highest CO2-capture capability up to >75% per mole of Ca(OH)2 as a sorbent. Similar levels of the ability to capture CO2 per mole of Ca(OH)2 can be found in other limestones, ranging from 14.85% to 34.07%. The results show a promising performance of raw limestones from different mining sites, allowing further study and observation of the possibility of CO2 emission reduction in the sustainable cement-production process.

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40

Belov, Vladimir, Temur Barkaya e Pavel Kuliaev. "Durability of fine-grained limestone concrete". E3S Web of Conferences 97 (2019): 02042. http://dx.doi.org/10.1051/e3sconf/20199702042.

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Abstract (sommario):

Production of effective building materials of high-density and high-durability is connected with the development of methods of modification of such materials on macro-, micro- and nanostructural levels. Presently the application of finest ingredients in admixture compositions such as limestone filler produced from local quarries is viewed as a primary task of cost reduction in limestone concrete manufacturing. The efficiency of limestone filler to enhance the durability of fine-grained limestone concrete is shown in tests performed. Limestone half inert filler conjointly with superplasticizer are found to enhance crack-resistance and reduces creep strains, which makes fine-grained limestone concrete the most effective and long-standing material. Knowledge of the stress-strain distribution in concrete with limestone fines under compression is important for the design of certain kinds of reinforced thin-walled concrete structures, such as shells, membranes and domes. These structures are manufactured with addition of both limestone filler and superplasticizer performing synergetic effect which leads to increasing a level of crack causing stresses.

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Cazotti, Maria Maiara, Liovando Marciano da Costa e Paulo Roberto Cecon. "Biogenic, sedimentary, and metamorphic limestone: a comparative characterization of soil amendment". Revista Ceres 66, n. 1 (febbraio 2019): 63–71. http://dx.doi.org/10.1590/0034-737x201966010009.

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ABSTRACT Liming acid soils is fundamental for agricultural activity such as the study and characterization of alternative liming material. The objective of this study was to characterize biological, sedimentary, and metamorphic limestones. The following limestones were studied: biogenic (BL), sedimentary (SL), commercial (CL), and marble (ML). This study evaluated total relative neutralizing power (TRNP), chemical composition, specific surface area, and Ca2+and Mg2+release at concentrations of 0.10, 0.50, 1.00, and 2.00 mol L-1 HCl, in addition to the effects on the soil 90 days after limestone application. The Si identified contributed to the lower TRNP of BL (73.7%) and CL (74.4%). At the lowest HCl concentrations, BL was the most reactive, but with an increase in concentration, ML became the most reactive. The highest CaO (58.32%) and MgO (13.05%) levels were observed in SL and ML, respectively, which contained the highest Ca2+(3.95 cmolcdm-3) and Mg2+ (1.09 cmolcdm-3) concentrations when applied to the soil. All the limestones increased pH and lowered soil H+Al. Soil Ca2+and Mg2+were influenced by the composition of the amendments.

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Eakes, D. J., C. H. Gilliam, G. J. Keever e J. W. Olive. "Dolomitic Limestone Form and Rate in Container Production of Woody Ornamentals". HortScience 32, n. 4 (luglio 1997): 592F—592. http://dx.doi.org/10.21273/hortsci.32.4.592f.

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Uniform liners of Soft Touch Holly (Ilex crenata 'Soft Touch') and Fashion azalea {Rhododendron 'Fashion') were potted into trade gallon containers of a 3: 1 by volume pinebark: peat moss medium amended with 8.3 kg of 17-7-12 Osmocote and 0.9 kg of Micromax per m3. Dolomitic limestone rates were 0,3, and 6 kg per m3 of medium applied as a finely ground or pelletized product. Medium solution pH increased with increasing rate of dolomitic limestone. Ground dolomitic limestone had a greater impact on medium solution pH than pelletized dolomitic limestone and differences increased as rate increased. Addition of ground dolomitic limestone at 6 kg per m3 reduced foliar color and growth of azalea. Amending with dolomitic limestone had little or no effect on holly foliar color or growth, regardless of rate.

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Shi, Jun, Fan Zhang, Jinping Zhuang, Zhangbao Wu, Rong Chen e Huixia Li. "Study on the Influence of SAP on Properties of White Fair-Faced Concrete with Limestone Powder". Advances in Materials Science and Engineering 2023 (3 gennaio 2023): 1–11. http://dx.doi.org/10.1155/2023/4994299.

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Abstract (sommario):

Introducing SAP internal curing material and limestone powder into white fair-faced concrete in order to greatly improve the durability of white fair-faced concrete, alleviate the influence of mechanical property deterioration caused by SAP, and facilitate the popularization and application of SAP and limestone powder in white fair-faced concrete. Therefore, this paper studies the effect of the content of SAP and limestone powder on the properties of white fair-faced concrete, conducts slump, electric flux, standard cube compressive strength, and splitting tensile strength tests, and examines SAP and limestone powder from a macroscopic perspective. The effect of the dosage on the properties of white, fair-faced concrete was explained by a scanning electron microscope (SEM) from a microscopic point of view. The results show that SAP can increase the slump of white fair-faced concrete, and the slump of SAP white fair-faced concrete increases with the addition of limestone powder content. Adding SAP can greatly reduce the electric flux of white fair-faced concrete. The addition of limestone powder can further reduce the electric flux and improve the durability and adding SAP will deteriorate the mechanical properties of white fair-faced concrete. Adding limestone powder is beneficial to the improvement of the mechanical properties of SAP mixed with white fair-faced concrete. Adding 30% limestone powder can give full play to the optimal performance of SAP white fair-faced concrete. SAP can refine the internal structure of white fair-faced concrete, and the filling and nucleation effects of limestone powder can improve the situation where SAP deteriorates the mechanical properties of white fair-faced concrete, further optimizing concrete internal structure.

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44

Nascimento, Klisman de Almeida do, Milton César Costa Camposita, Wildson Benedito Mendes Brito, Elilson Gomes de Brito Filho, José Maurício da Cunha, Flávio Pereira de Oliveira, Luís Antônio Coutrim dos Santos, Vânia Silva Fraga e Douglas Marcelo Pinheiro da Silva. "Liquid limestone in the acidity correction of a Dystric Cambisol for Brachiaria production in Humaitá, Amazonas." Research, Society and Development 9, n. 8 (11 luglio 2020): e415985517. http://dx.doi.org/10.33448/rsd-v9i8.5517.

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Abstract (sommario):

Conventional solid limestone most commonly used in agriculture generally has disadvantages in handling, in addition to a certain infeasibility for small producers when compared to the use of liquid limestone with high purity and reactivity. Therefore, a better understanding of the dynamics of liquid limestone employed in soil acidity correction is important. Thus, this work proposes the use of liquid limestone to correct the acidity of a Dystric Cambisol in pasture cultivation in Humaitá, AM. An experiment was carried out in a greenhouse, where plastic pots were prepared for sowing Brachiaria brizantha, in a randomized block design with five treatments and four replications (T1 = witness, T2 = 2.5 L, T3 = 5 L, T4 = 10 L and T5 with common limestone). After 90 days of planting, the shoot and root size of both fresh and dry mass of each treatment were evaluated, as well as the number of tillers. The tillering of B. brizantha was highly responsive to the addition of liquid and common limestone, so that the higher the dose, the greater the results. In contrast, the treatments for fresh and dry shoot and root biomass production did not differ significantly between themselves, explaining why the product is still not well accepted and used by dealers and farmers.

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45

Vyšvařil, Martin, Tomáš Žižlavský e Patrik Bayer. "The Effect of Aggregate Type on the Properties of Lime Mortars". Applied Mechanics and Materials 861 (dicembre 2016): 141–48. http://dx.doi.org/10.4028/www.scientific.net/amm.861.141.

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Abstract (sommario):

Lime mortars represent indispensable building materials that have been used for centuries in civil engineering. Considering the necessity of numerous restoration work on historical buildings, a research of the applicability and suitability of various types of plasters for repairing the historical plasters has been developed. This work presents the applicability of limestone aggregate and limestone fines to aerial lime-based mortars. The role of aggregates on the properties of lime mortars is examined in this paper by comparing pure quartz sand and limestone aggregate and its quantity in the mortar. It was found that limestone aggregate produced the comparable or higher mortar strengths than quartz aggregate and slightly increased porosity, water absorptive capacity and carbonation rate of the mortars. Partially replacement of aggregate by limestone fines has caused dramatic growth in strength, especially in mortars with high content of binder. The applied limestone aggregate is convenient to lime-based mortars and the addition of limestone fines contributes to better mechanical properties of lime mortars.

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46

Xiao, Jia, Cheng Fu Gou, Cai Yun Xu, Hao Xing e Yong Gang Jin. "Study on the Properties of Ground Limestone-High Alumina Cement Gelation System". Advanced Materials Research 317-319 (agosto 2011): 489–97. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.489.

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Abstract (sommario):

Effects of various amounts of ground limestone on the setting time, fluidity and compressive strength of high alumina cement were described in this paper. Microstructure analyses were performed by SEM. The results indicate that the initial setting time, the final setting time, the fluidity and the compressive strength of the pastes increase first and decrease later with the ground limestone content increasing, all of which reach the maximum when the ground limestone content is 3%. Meanwhile, an increase of the fineness of the ground limestone produces a shorter setting time, the fluidity of the pastes increases when the content of the ground limestone increases, and the compressive strength of the hardened pastes increases with the ground limestone content increasing and decreases with water-binder ratio increasing. The 28d strength of the pure high alumina cement paste is lower than the 3d strength, appearing the strength shrinkage, which can be improved by a proper addition of the ground limestone.

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WANG, FA-GUO, AI-HUA WANG, RONG-RONG HE, DONG-MEI YANG, CHUN-MEI HE, DONG-MING LIU, JEREMY MOYNIHAN, QI-FEI YI e FU-WU XING. "Phytogeography of pteridophytes on limestone areas in Guangdong, China". Phytotaxa 317, n. 2 (15 agosto 2017): 81. http://dx.doi.org/10.11646/phytotaxa.317.2.1.

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Abstract (sommario):

Guangdong Province, located in southern China, is of great interest in studies of plant geography and conservation in limestone areas because of its rich biodiversity. We: (1) performed a phytogeographical analysis of pteridophytes in the limestone areas in Guangdong, (2) evaluated and determined levels of endemism, and (3) identified affinities with the floras of neighboring limestone areas. We found that some families show a preference for limestone habitats, e.g., Hypodematiaceae, Lygodiaceae, and Adiantaceae, are typical elements among pteridophytes in the limestone regions of Guangdong. In addition, some genera or section, such as Hypodematium, and Polystichum sect. Cyrtogonellum, show an exclusive preference for limestone habitats. The predominant phytogeographical affinities identified were East Asia, Chinese endemic, and Tropical Asia. We concluded that: (1) the limestone fern flora of Guangdong is principally subtropical in nature and represents southern subtropical flora at the margins of the northern tropics, with a strong interaction with the East Asian flora, (2) the limestone fern flora of Guangdong has a phytogeographical affinity with Japan, though the floras of neighboring Guangxi and Hainan Provinces have higher similarity with it.

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Celik, M. S., A. Shakeel, H. Y. Al-Yousef e H. S. Al-Hashim. "Adsorption of Ethoxylated Sulfonates on Limestone". Adsorption Science & Technology 5, n. 1 (marzo 1988): 29–45. http://dx.doi.org/10.1177/026361748800500104.

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Stastic adsorption experiments have been conducted to investigate the adsorption and precipitation behavior of various ethoxylated sulfonates from Saudi Arabian limestone samples under high-salinity (20%) and high temperature conditions (90°C). The effect of parameters such as salinity, pH, temperature, ethoxylation number, oil and alcohol addition has been investigated. Mechanisms governing surfactant adsorption on limestone are elucidated. A surfactant formulation has been designed to achieve minimum surfactant loss for Saudi Arabian limestone reservoirs.

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Sokolař, Radomír, Lucie Vodová e Mikuláš Šveda. "Limestone Sludge in the Brick Body". Advanced Materials Research 1000 (agosto 2014): 158–61. http://dx.doi.org/10.4028/www.scientific.net/amr.1000.158.

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Influence of limestone sludge (generated during the washing process of limestone crushed aggregates) with high content of CaO in the form of calcite on the properties of brick body made from non-calcareous sludge (from the washing process of quartz sand) as a basic plastic brick clay was determined. Presence of calcite very distinctly influenced the firing process and properties of fired body. Limestone sludge decreases firing shrinkage, bulk density and coefficient of thermal conductivity of the brick body after the firing in the range of 850 – 950 °C. Higher modulus of rupture and water absorption is typical for fired bodies with limestone sludge addition. Most of these improvement are caused by the formation of anorthite only in the bodies based on the limestone sludge.

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Argın, G., e B. Uzal. "Enhancement of pozzolanic activity of calcined clays by limestone powder addition". Construction and Building Materials 284 (maggio 2021): 122789. http://dx.doi.org/10.1016/j.conbuildmat.2021.122789.

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