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1
Sediq, Vaismoradi, and reza Goodarzi Amir. "Investigation of Interaction between Rock Materials and Concrete Slabs in Concrete- Face Rock-Fill Dam (CFRD)." Journal of Civil Engineering and Materials Application 2, no. 1 (2018): 1–23. https://doi.org/10.22034/jcema.2018.91983.
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In the CFRD dams, a concrete-face with a finite thickness is placed on the upstream side of the dam, which prevents water leakage from the reservoir. The construction of these dams with different heights and various specifications of materials have been welcomed a lot. Therefore, construction of CFRD is appropriate in pumped-storage reservoirs. However, due to the important role of concrete-face, the necessity of optimal studies in order to evaluate the behavior of this type of dams is obvious. In this research, the lower reservoir of Siah Bishe was studied by finite element method in order to investigate the interaction between rock-fill materials and simulated concrete-face and by an appropriate behavioral model in a three- dimensional mode that can simulate the behavior of materials in the body of the dam well. In this research, Plaxis software was used for modeling and static analysis was performed to determine deformations and stresses made in the dam and concrete slab. The elastoplastic behavioral model of Mohr-Coulomb was used to model the behavior of the materials and the technical specifications of the materials used in the body of the dam and concrete-face slab have been applied. The maximum value of settlement calculated by the software from the beginning of the constriction to filling the reservoir under the effect of gravity is 670 millimeter and the maximum settlement after phase 3 in the mode of the full reservoir in long term is 32 millimeter and the maximum horizontal displacement is 52 millimeter. Finally, the results of the settlements were compared to results of the instrumentation. The results indicate the approximation of results of the numerical modeling with results obtained from instrumentation.
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PALTINEAN, Gertrud-Alexandra, Gheorghe Tomoaia, Levente-Zsolt RACZ, Aurora MOCANU, and Maria Tomoaia-Cotisel. "INTERACTION OF BIOACTIVE COMPOUNDS WITH CERAMIC MATERIALS – A REVIEW." Annals of the Academy of Romanian Scientists Series on Physics and Chemistry 7, no. 2 (2022): 47–82. http://dx.doi.org/10.56082/annalsarsciphyschem.2022.2.47.
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This review examines the interaction between silymarin (SIL) and other plant-based bioactive compounds such as curcumin (CCM), piperine (PIP), resveratrol (RES), and icariin (ICA). Their combination revealed synergistic effects on colon (HCT116), breast (T47D) tumor cells, hepatocellular carcinoma, and periodontal disease. The review also addresses the interaction between these plant extracts with ceramic materials such as hydroxyapatite (HAP) and carotenoids with concrete examples of biomedical applications. Silymarin’s interaction with chemotherapeutic drugs (doxorubicin-DOX, paclitaxel-PCT and 5-Fluorouracil-5-FLU) and gold nanoparticles-GNPs and silver nanoparticles-SNPs is also debated. All these combinations can form composites of major importance in the biomedical field and to contribute significantly to orthopedic surgery where materials are needed for implants that face severe infections. This short review highlights the variety of multifunctional nanoparticles that open new opportunities in cancer treatment and the need to use the Langmuir Blodgett Technique that mimics the biological membrane and provides rich medical information.
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Karalar, Memduh, and Murat Çavuşli. "Effect of Normal and Shear Interaction Stiffnesses on Three-Dimensional Viscoplastic Creep Behaviour of a CFR Dam." Advances in Civil Engineering 2018 (September 2, 2018): 1–17. http://dx.doi.org/10.1155/2018/2491652.
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Rockfill materials and foundation continuously interact with each other during lifetime of the rockfill dams. This interaction condition alters the viscoplastic behaviour of these dams in time. For this reason, examination of the time-dependent viscoplastic interaction analyses is vital important for monitoring and evaluating of the future and safety of the rockfill dams. In this study, it is observed how the time-dependent displacement and stress behaviour of a concrete-faced rockfill (CFR) dam change by the effect of the normal and shear interaction spring stiffness parameters. Ilısu Dam that is the longest concrete-faced rockfill dam in the world now and has been completed in the year 2017 is selected for the three-dimensional (3D) creep analyses. The 3D finite difference model of this dam is modelled using FLAC3D software that is based on the finite difference method. The concrete slab, rockfill materials, foundation, and reservoir water are separately created for the 3D interaction analyses. A WIPP-creep viscoplastic material model and a burger-creep viscoplastic material model that are special material models for the creep analyses of rockfill dams are used for concrete slab and for rockfill materials and foundation, respectively. Totally 20 different interaction parameters (normal and shear stiffnesses) are separately defined between the rockfill materials and the foundation to represent the interaction condition. According to numerical analyses, the effect of these various interaction parameters on the viscoplastic behaviour of the Ilısu Dam is evaluated for the empty and full reservoir conditions. As a consequence, the most critical normal and shear stiffnesses’ range for creep analyses of the rockfill dams is determined. Afterwards, the long-term viscoplastic interaction behaviour of Ilısu Dam is examined during 35 years considering this important stiffness values. Settlements, horizontal displacements, and principal stresses are evaluated for both reservoir conditions, and these results are compared with each other in detail.
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Choinska, Marta, Hayder Al-Khazraji, Nathan Benkemoun, and Abdelhafid Khelidj. "Influence of tensile cracking and of aggregate size on concrete permeability." MATEC Web of Conferences 163 (2018): 02001. http://dx.doi.org/10.1051/matecconf/201816302001.
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The aim of this study is to investigate the interaction between crack opening (COD), aggregate size and gas transfer in concrete submitted to mechanical loading in the Brazilian splitting tensile test. The lab-made devices have been developed to investigate physical phenomena during loading and to provide data to validate a developed mesoscale hydromechanical model by the same authors, based upon a 3D lattice approach to represent the heterogeneity of the material [1]. Experimental studies has been carried out on five materials with different aggregate sizes. The results emphasize that permeability of mortar increases with cracking following a sigmoid law, with the most important kinetics due to passingthrough connected crack growth, after nonsymmetric one-face crack initiation. Furthermore, the obtained results highlight that permeability increase, due to aggregate size, may be separated from permeability increase due to tensile cracking: for all the five materials tested results fall on the same master sigmoid curve. This behaviour law represents a strong advantage for concrete modelling.
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Podvysotckii, Aleksei A., Mikhail P. Sainov, and Andrey Yu Kirichenko. "Performance comparison of various types of embankment dams in relation to the conditions of the Mullalakh HPP." Vestnik MGSU, no. 2 (February 2021): 202–19. http://dx.doi.org/10.22227/1997-0935.2021.2.202-219.
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Introduction. Several types of embankment dams are used in the hydraulic engineering practice. However, the choice of a dam is individual for each hydraulic engineering project, as it takes account of specific features and natural conditions. This paper compares two types of rockfill dams (the one having a concrete face and the other having an asphalt-concrete diaphragm) in relation to the Mullalakh HPP on the Pskem River in the Republic of Uzbekistan. The dam height is 85 m. The comparison was performed from the standpoint of the dam performance in case of exposure to static forces and high seismicity.
 Materials and methods. The analysis of (1) the stress-strain state (SSS), (2) the stability of slopes exposed to regular and irregular load combinations was conducted for two types of dams. All calculations were performed in the two-dimensional domain. The analysis of the stress-strain state took account of the non-linear behavior of the soil ground and the contact interaction between structural elements. Seismic loads, included into the scope of irregular loads, were identified using the response spectrum method applied to particular periods and self-oscillation modes. Slope stability was analyzed with regard for the stress state of soils identified in the course of SSS calculations.
 Results. Each type of embankment dams has its specific features. The asphalt diaphragm dam is worse at perceiving high seismic loads. Its SSS during an earthquake features strength loss and emergence of soil discontinuity zones. The disadvantage of a concrete face dam is the insufficient safety of its anti-seepage element. Supplementary measures are needed to ensure the appropriate stress state of the face. Another finding is that the slopes of both types of dam do not demonstrate a sufficient stability factor, if the slope ratio equals to 1.5 during a 9-point earthquake.
 Conclusions. In high seismicity regions, a concrete faced dam demonstrates better performance than the asphalt diaphragm dam if both are exposed to static and seismic forces.
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Taboada, María Beatriz, and Guadalupe Álvarez. "Dialogical experiences in, for, and from technologically mediated contexts in teacher education." Dialogic Pedagogy: An International Online Journal 10 (December 13, 2022): DT123—DT151. http://dx.doi.org/10.5195/dpj.2022.450.
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This work proposes an analysis of pedagogical experiences developed in the context of university teacher education in dialogue with two different chronotopes: habitual face-to-face teaching modality and exceptional non-face-to-face teaching modality due to the COVID lockdown. We consider here two cases of Language and Literature teacher education courses in two universities in Argentina. Both experiences share the search for an equitable, dialogical interaction, in which there is a recovery of the students’ opinions and criteria for the progressive and collaborative elaboration of knowledge. From a qualitative perspective, we resorted to autoethnographic narratives elaborated by the responsible teaching teams of the courses. In the approach we propose, there is a dialogue among different elements of our inquiry: a dialogue between the conceptions that we assume as teachers and researchers about teaching in face-to-face and virtual environments; a dialogue between the conceptualizations and concrete teaching-decisions; between the contexts of performance and the possibilities offered by virtuality; between the pedagogical experiences and the narratives; between the records and other materials that allow us to reconstitute these experiences; and between our voices and the voices of students and graduates who give us back evaluations and sustain the continuity of the dialogue. The analysis accounts for the definition of different chronotopes in the experiences and moments addressed. In both cases, the differences observed respond to contextual factors, particularities of the courses and the previous experiences that the teaching teams have had with ICT. Beyond the above-mentioned differences, for the exceptional non-face-to-face proposals, a greater stability in the proposed sequences and in the dynamics involved is observed in the two experiences, which seeks to generate greater predictability.
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Giroudon, Marie, Cédric Roosz, Mehdi Bista, Matthieu Peyre Lavigne, Laurie Lacarrière, and Alexandra Bertron. "Interactions between hydrated cement pastes and aggressive ammonium: experimental batches characterization." MATEC Web of Conferences 364 (2022): 05010. http://dx.doi.org/10.1051/matecconf/202236405010.
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Agricultural and food industries concrete facilities face chemically aggressive conditions that can damage their microstructure and reduce their lifespan. They are particularly exposed to ammonium-rich environments from natural microbial activity. The poorly crystalline mineralogy of hydrated cement pastes, the compositional variability of the phases and their reactivity make the geochemical behaviour of such materials difficult to investigate and predict over both large periods of time and wide variety of chemical compositions. This work aims (i) to assess the stability of the cement phases involved in ammonium-rich conditions as well as to identify the alteration products, and (ii) to understand the mechanisms and intensity of alteration. To do this, experiments were carried out both on OPC paste powder and on monolithic OPC pastes, degraded by an ammonium nitrate solution in semi-batch conditions. The powder was gradually added to the aggressive solution while the monoliths were immersed for 16 weeks in regularly renewed solution. The pH and the concentration of the chemical elements in solution were monitored over the experiments. The microstructural, chemical and mineralogical changes of the samples were analysed by scanning electron microscopy, electron probe micro-analysis and X-Ray diffraction and showed phenomena of dissolution, leaching and carbonation.
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Xu, Lina, Haoyun Deng, Lei Niu, Yongmei Qian, and Daohan Song. "Study on Soil Displacement Fields around the Expanded Body of Drill-Expanded Concrete Piles Based on DIC Technique." Applied Sciences 11, no. 19 (2021): 9097. http://dx.doi.org/10.3390/app11199097.
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The soil displacement field around a drill-expanded concrete pile is noticeably different from that of an equivalent section pile placed under axial load due to the mutual embedment between the expanded body and the soil. It is important to study the soil displacement field around drill-expanded concrete piles in order to understand the mechanisms of interaction between the pile and the soil. First, the model test of the half-face pile installed in undisturbed soil and the model test of the half-face pile installed in sand were used to study the soil displacement field around the pile. Then, the entire process of the soil displacement field’s formation and development under the load was observed by using digital image correlation (DIC) techniques. Finally, numerical simulation was used to verify the results of the model tests. The results show that the displacement characteristics of the soil around the pile in the undisturbed soil and sand are basically the same. There is a clear soil compression zone under the expanded body, and the magnitude and density of the displaced soil in the compression zone are much higher than in other areas. Both the vertical displacement and the horizontal displacement gradually decrease as the distance from the expanded body and the burial depth increase. The horizontal displacement of the soil under the expanded body follows a trend of first moving toward the pile body and then moving away from it. The results of the numerical simulation are basically consistent with the results of the model test, indicating that the results of the model test are relatively reliable.
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Marinelli, Simona, Maria Angela Butturi, Bianca Rimini, Rita Gamberini, and Miguel Afonso Sellitto. "Estimating the Circularity Performance of an Emerging Industrial Symbiosis Network: The Case of Recycled Plastic Fibers in Reinforced Concrete." Sustainability 13, no. 18 (2021): 10257. http://dx.doi.org/10.3390/su131810257.
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In recent times, the construction industry has been handling circular economy strategies in order to face the most important challenges in the sector, namely the lack of raw materials and the environmental impacts derived from all the processes linked to the entire supply chain. The industrial symbiosis approach represents an effective strategy to improve the circularity of the construction industry. This study analyses the circularity performance of an emerging industrial symbiosis network derived from the production of a cement mortar reinforced with recycled synthetic fibers coming from artificial turf carpets. From the collection of artificial turf carpets at the end-of-life stage it is possible to recover several materials, leading to potential unusual interactions between industries belonging to different sectors. A suitable indicator, retrieved from the literature, the Industrial Symbiosis Indicator (ISI), has been used to estimate the level of industrial symbiosis associated with increasing materials recirculation inside the network. Four scenarios—ranging from perfect linearity to perfect circularity—representing growing circularity were tested. Findings demonstrate that the development of an effective industrial symbiosis network can contribute to improving the circular approach within the construction sector, reducing environmental and economic pressures.
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Karalar, Memduh, and Murat Çavuşli. "Evaluation of 3D Nonlinear Earthquake Behaviour of the Ilısu CFR Dam under Far-Fault Ground Motions." Advances in Civil Engineering 2019 (January 8, 2019): 1–15. http://dx.doi.org/10.1155/2019/7358710.
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In the recent times, many huge concrete face rockfill dams (CFRDs) have been modelled and constructed in the world, and many of these dams are located on the strong earthquake zones. Examination of the seismic behaviour of a CFR dam built on the seismic zone is very important to assess the safety and future of the dam. For this reason, the nonlinear earthquake behaviour of these dams should be constantly observed taking into account the seismicity of the zone. In this study, three-dimensional (3D) seismic behaviour of the Ilısu dam built on the East Anatolian Fault (EAF) line is examined considering the effect of the important various far-fault earthquakes. The 3D finite difference model of the Ilısu dam is created using the FLAC3D software based on the finite difference method. The dam body, foundation, and concrete slab constantly interact during the lifetime of the CFRDs. Therefore, the special interface elements are defined between the dam body, concrete slab, and foundation to represent the interaction condition. The Mohr–Coulomb nonlinear material model is used for the rockfill materials and foundation. Moreover, the concrete slab is modelled considering the Drucker–Prager nonlinear material model to represent the nonlinearity of the concrete. Very special seismic boundary conditions rarely used for CFR dams in the past are used in this work. These boundary conditions are free-field and quiet boundary conditions. The free-field boundary condition that is a very important boundary condition for the nonlinear seismic analyses is considered for the lateral boundaries of the 3D model. In addition, the quiet artificial boundary condition is used for the bottom of the foundation. While defining these boundary conditions, the special fish functions are created and defined to the software. Moreover, the hysteric damping coefficients are separately calculated for all of the materials. These special damping values are defined to the FLAC3D software using the special fish functions to capture the effects of the variation of the modulus and damping ratio with the dynamic shear-strain magnitude. In the numerical analyses, a total of 7 various strong far-fault earthquakes are used for the 3D nonlinear earthquake analyses, and 7 different numerical analyses are performed for the full-reservoir condition of the Ilısu CFR dam. According to the seismic results, the principal stresses for the three critical nodal points on the dam body surface are examined and evaluated in detail. It is clearly understood that the nonlinear seismic behaviour of the Ilısu dam changes depending on the magnitudes and periods of the far-fault earthquakes. Each far-fault earthquake has different seismic effects on the nonlinear principal stress behaviour of the Ilısu CFR dam.
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Dang, Jiaxin, Min Tu, Xiangyang Zhang, and Qingwei Bu. "Analysis of the Influence Characteristics of the Support Stability of a Fully Mechanized Coal Mining Face under the Hard Roof Mining Pressure." Shock and Vibration 2021 (October 29, 2021): 1–15. http://dx.doi.org/10.1155/2021/1307000.
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The conditions of the hard roof in my country vary greatly, ranging from a few meters to tens of meters or even hundreds of meters in thickness. The coal reserves under the hard roof account for about one-third of the total reserves. At present, nearly 40% of fully mechanized mining faces that belong to the hard roof working face has the problem of mining in the hard roof working face. This has a serious impact on the load-bearing stability of the fully mechanized support, and it is urgent to solve the problem of strong underground pressure dynamic disaster under the condition of the hard roof. Based on the research background of 11129 working face in Zhangji Coal Mine in Huainan, this paper constructs a mechanical model of the interaction between the cantilever beam of the hard roof of the stope and the support and then the force distribution equation of the bearing capacity of the supports at different positions of the roof during the periodical rotation of the working face is obtained, which is combined with numerical simulation and engineering site to verify. The research results show that the bearing stability of the support is significantly affected by factors such as the buried depth H, the roof elastic modulus E, the roof thickness h, and the roof cantilever length l0, but most of the influencing factors belong to the geological occurrence conditions of the coal seam itself. Presplit blasting of the roof in advance can effectively destroy the integrity of the roof itself and reduce the periodic breaking distance, thereby improving the apparent environment of roof rock pressure and reducing the force on the working face support. According to the specific geological environment of the 11129 working face, the cutting plan of the cut hole is given out, along the groove 0∼200 and 200∼700 m of the concrete presplitting blasting. The stent force of the top-cutting section fluctuates in the range of 3360.8–4347.9 kN in the range of control top distance (5275∼6175 mm). The load-bearing pressure of the stent before top-cutting is about 1.8 times of that after top-cutting. The pressure distribution of the hydraulic support in the numerical simulation stope is approximately “Λ” in the middle and the low on the two sides. The simulated value is slightly smaller than the theoretical calculation value. The reason is that the goaf is backfilled during the simulation process, and the roof has a certain ability to bear the load. Real-time understanding of the “roof-support” mechanical relationship can effectively ensure the safe and efficient mining of the 11129 working face and also provide experience for the subsequent mining of group B coal in the later period.
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Aloisio, Angelo, and Rocco Alaggio. "Experimental Estimation of the Elastic Modulus of Concrete Girders from Drive-By Inspections with Force-Balance Accelerometers." Shock and Vibration 2021 (August 4, 2021): 1–12. http://dx.doi.org/10.1155/2021/1617526.
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Parametric identification of bridges using instrumented vehicles can be challenging, mainly due to the reduced length of the time series associated with the bridge span under test. This research discusses the practicability of a time-domain identification method based on the use of an instrumented vehicle. The highest cross-correlation between the bridge response from an elementary analytical model and the experimental one, acquired by a moving force-balance accelerometer, yields the unknown model parameter. The effect of vehicle-bridge interaction is removed by proper filtering of the signals. Specifically, the authors estimate the elastic moduli of seven prestressed concrete bridges and compare a subset of the results to the outcomes of static load tests carried out on the same bridges. There is a good correlation between the elastic moduli from the instrumented vehicle and those from static load tests: the method grasps the approximate value of the elastic modulus of concrete. Still, the data do not return an excellent match due to the bias in the estimation of the deflection shape—the paper remarks on the issues faced during the experimental tests and proposes possible enhancements of these procedures.
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Suwarsiah, Suwarsiah, Handoko Santoso, and Achyani Achyani. "PERANAN MEDIA INTERAKTIF DALAM MENINGKATKAN KETERAMPILAN BERPIKIR KRITIS." BIOLOVA 2, no. 2 (2021): 108–13. http://dx.doi.org/10.24127/biolova.v2i2.1107.
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Abstrak: Media pembelajaran adalah segala alat dan bahan yang dapat digunakan untuk mencapai tujuan pendidikan, media pembelajaran berfungsi sebagai alat komunikasi dalam mengatasi keterbatasan pengalaman siswa, media dapat memberikan pengalaman yang holistik dari hal yang konkrit ke hal yang abstrak. Media multimedia interaktif berupa flashdisk dapat dikemas secara menarik baik dari segi gambar, animasi, teks, maupun audio sehingga dapat timbul respon positif dari siswa dan dapat membantu meningkatkan kemampuan berpikir kritis, berpikir kritis merupakan proses berpikir intelektual dalam dimana pemikir sengaja menilai kualitas pemikirannya, pemikir menggunakan pemikiran reflektif, mandiri, jernih, dan rasional. Peran media sangat besar dalam melakukan komunikasi dan interaksi yang efektif antara guru dan siswa serta meningkatkan kemampuan berpikir kritis. Kemampuan berpikir kritis sangat penting dalam menghadapi persaingan global yang semakin ketat. Keterampilan berpikir kritis pada peningkatan daya saing siswa berupa pengetahuan dan keterampilan global.
 
 Abstract : Learning media are all tools and materials that can be used to achieve educational goals, learning media function as a communication tool in overcoming the limitations of students' experiences, the media can provide a holistic experience from concrete to abstract things. Interactive multimedia media in the form of flash can be packaged attractively both in terms of images, animation, text, and audio so that positive responses can arise from students and can help improve the ability to think critical, critical thinking is an intellectual thought process in which thinkers deliberately assess the quality of thought, thinkers use reflective, independent, clear, and rational thinking. The role of the media is very large in making effective communication and interaction between teachers and students and increasing critical thinking skills. The ability to think critically is very important in the face of increasingly fierce global competition. Critical thinking skills are aimed at increasing students' competitiveness in the form of global knowledge and skills.
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Saberi, Miad, Charles-Darwin Annan, and Jean-Marie Konrad. "Numerical analysis of concrete-faced rockfill dams considering effect of face slab – cushion layer interaction." Canadian Geotechnical Journal 55, no. 10 (2018): 1489–501. http://dx.doi.org/10.1139/cgj-2017-0609.
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In this study, the effect of concrete face slab – cushion layer interface behavior on the performance of face slabs in concrete-faced rockfill dams (CFRDs) is investigated using the finite element method. The body of the CFRD is simulated by the cap elastoplasticity model while the interface zone between the concrete face slab and the gravelly cushion layer is simulated explicitly by an advanced interface constitutive model, developed in the framework of critical state soil mechanics and state parameters, and capable of simulating volumetric behavior and stress path dependency. The effect of elastic and elastoplastic material behavior and water level on the stress and displacement responses of the concrete face slab is examined, and the influence of the roughness at the interface area between the concrete face slab at the contact face and the cushion layer on the performance of the concrete face slab is investigated. Comparison of the results with and without the explicit consideration of the interface behavior shows the importance of incorporating advanced constitutive interface modeling in the design and analysis of CFRDs.
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Borodina, T. I., G. E. Val'yano, L. P. Krishchenko, S. V. Onufriev, E. P. Pakhomov, and V. A. Petukhov. "Interaction between metallic melts and zirconia concrete." Refractories 37, no. 11 (1996): 391–95. http://dx.doi.org/10.1007/bf02238705.
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Wu, Hwai-Chung. "Mechanical Interaction between Concrete and FRP Sheet." Journal of Composites for Construction 4, no. 2 (2000): 96–98. http://dx.doi.org/10.1061/(asce)1090-0268(2000)4:2(96).
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Karam, Gebran N., and Hwai-Chung Wu. "Mechanical Interaction between Concrete and FRP Sheet." Journal of Composites for Construction 5, no. 3 (2001): 212. http://dx.doi.org/10.1061/(asce)1090-0268(2001)5:3(212).
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Ali, M. S. Mohamed, D. J. Oehlers, and M. A. Bradford. "Interaction between Flexure and Shear on the Debonding of RC Beams Retrofitted with Compression Face Plates." Advances in Structural Engineering 5, no. 4 (2002): 223–30. http://dx.doi.org/10.1260/136943302320974590.
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Steel and FRP plating reinforced concrete structures is increasingly being used for retrofitting. Plates can be bonded to any surface of a beam or slab, although it is common practice to adhesively bond plates to the tension faces. The addition of these tension face plates reduces the sectional ductility of the beam. Furthermore, these tension face plates are prone to premature debonding because the stress concentrations induced by these plates overlap with those induced by the tension reinforcing bars adjacent to the plate. Solutions to these two problems, which are the subject of this paper, consist of: adhesively bonding plates to the compression faces to counterbalance the tension face plates and, hence, improve the beam sectional ductility; and to extend the tension face plates, in continuous beams, past the points of contraflexure so that they terminate in a compression face. In this paper, eleven new tests on 340 mm deep beams are presented that show that compression face plates are less prone to debonding than tension face plates.
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Li, Guo-Wei, Cheng-Yu Hong, Jian Dai, Liang Yu, and Wan-Huan Zhou. "FBG-Based Creep Analysis of GFRP Materials Embedded in Concrete." Mathematical Problems in Engineering 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/631216.
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This paper presents a typical study regarding the creep interaction behavior between prestressed glass fiber reinforced polymer (GFRP) bar and concrete when this GFRP bar is subjected to a constant external pullout force. A number of optical fiber Bragg grating (FBG) sensors were mounted on GFRP bar surface by using an innovative installation method to measure strain distributions. Test results indicate that the complicated interaction at GFRP bar-concrete interface can be evaluated using a transitional factor. Variation trends of this transitional factor indicate three typical zones characterized by different strain/stress variation trends of the GFRP bar when prestress values are sustained at specific levels. These three typical zones include stress release zone, stress transition zone, and continuous tension zone. Test results also suggest that the instant stress loss at the interaction interface between concrete and GFRP bar was quite limited (less than 5%) in present test. Contributed proportion of each GFRP bar section was obtained to represent the creep behavior of the GFRP bar embedded in concrete. This investigation improved the understanding of the short-term interaction behavior between prestressed GFRP bar and concrete.
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Bakunov, O. V., L. B. Borovkova, L. P. Krishchenko, S. V. Onufriev, E. P. Pakhomov, and V. A. Petukhov. "Interaction between gravitation-hardened zirconia concrete and metallic melts." Refractories 36, no. 11 (1995): 341–46. http://dx.doi.org/10.1007/bf02227462.
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Cen, Wei Jun, Hui Sun, and Kun Xiong. "Dynamic Interaction between Reservoir and a High Concrete Face Rockfill Dam on Deep Alluvium Deposit." Applied Mechanics and Materials 353-356 (August 2013): 833–36. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.833.
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Potential-based fluid model and Westergaard added mass model were used to reflect the dynamic interaction of reservoir-CFRD(concrete face rockfill dam)-foundation coupling system. The deep alluvium deposit was treated as porous medium using Biot's dynamic consolidation theory. In the coupled analysis, the paper focused on hydrodynamic pressures in the reservoir zone, dynamic response and pore water pressure in the structure zone. The result shows that the dynamic response of added mass model is greater than that of potential-based fluid model. The porous medium of alluvium deposit is of great significance in performing soil liquefaction analysis and reservoir-dam-foundation system.
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Diaz, C., C. Cornadó, and A. Albareda. "Damage in face-brick facades placed between concrete slabs." Journal of Building Engineering 30 (July 2020): 101312. http://dx.doi.org/10.1016/j.jobe.2020.101312.
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Combrinck, Riaan, Lourens Steyl, and William P. Boshoff. "Interaction between settlement and shrinkage cracking in plastic concrete." Construction and Building Materials 185 (October 2018): 1–11. http://dx.doi.org/10.1016/j.conbuildmat.2018.07.028.
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Wang, R., J. Li, T. Zhang, and L. Czarnecki. "Chemical interaction between polymer and cement in polymer-cement concrete." Bulletin of the Polish Academy of Sciences Technical Sciences 64, no. 4 (2016): 785–92. http://dx.doi.org/10.1515/bpasts-2016-0087.
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Abstract Polymers are widely used in cement mortar and concrete modification due to their significant role in improving the overall performance of cement-based materials. Their physical interaction is well-accepted, while less attention is given to chemical interaction between the polymers and cement. Through a review of prior arts, chemical interactions are discussed and summarized in this paper. Various chemical interactions may take place between cement and different types of polymers. Understanding these chemical interactions will play an important role in clarifying the relationship between microstructure and macrostructure of polymer-modified cementitious materials. Authors expressed and proved the conviction that the organic-inorganic (Polymer-Portland cement) composite with some components chemically bonded, in parallel to the physical interaction, will be the next stage in concrete technology progress.
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van Schalkwyk, F., and E. Kearsley. "The influence of concrete compressive strength and specimen size on the compression stress block parameters of reinforced concrete." Journal of the South African Institution of Civil Engineering 60, no. 4 (2018): 34–44. http://dx.doi.org/10.17159/2309-8775/2018/v60n4a.
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This paper describes the influence of concrete compressive strength and specimen size on the fundamental characteristics of the flexural compressive stress-strain distribution. The main variables were specimen size and cylinder compressive strength. A total of 27 concrete specimens were subjected to flexural tests, with specific reference to analysis of the compression stresses, produced by varying two independent loads in a configuration aimed at controlling the strain distribution. These loads generated a condition of zero strain on the one face of the specimen, and a condition of maximum flexural compression strain on the opposite face. From the strain distribution, the stress-strain curves and stress block parameters were determined, and the influence of specimen size on the stress block parameters described using the Modified Size Effect Law (MSLE). Using a modified form of the moment-axial force (M-N) interaction diagram the BS 8110-1 (1997), SANS 0100-1 (2000), ACI-318 (2014) and EN 1992-1-1 (2004) codes of practice were compared for the design of reinforced concrete beams containing South African materials.
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Wang, Xiaowei, Juntao Chen, Ming Xiao, and Danqi Wu. "Seismic Response Analysis of Concrete Lining Structure in Large Underground Powerhouse." Mathematical Problems in Engineering 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/4106970.
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Based on the dynamic damage constitutive model of concrete material and seismic rock-lining structure interaction analysis method, the seismic response of lining structure in large underground powerhouse is studied in this paper. In order to describe strain rate dependence and fatigue damage of concrete material under cyclic loading, a dynamic constitutive model for concrete lining considering tension and shear anisotropic damage is presented, and the evolution equations of damage variables are derived. The proposed model is of simple form and can be programmed into finite element procedure easily. In order to describe seismic interaction characteristics of the surrounding rock and lining, an explicit dynamic contact analysis method considering bond and damage characteristics of contact face between the surrounding rock and lining is proposed, and this method can integrate directly without iteration. The proposed method is applied to seismic stability calculation of Yingxiuwan Underground Powerhouse, results reveal that the amplitude and duration of input seismic wave determine the damage degree of lining structure, the damage zone of lining structure is mainly distributed in its arch, and the contact face damage has great influence on the stability of the lining structure.
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Zhao, Quan Bin, and Xin Liang Jiang. "Research of Bond-Slip Constitutive Relation Model between Fiber Gypsum Board and Concrete Materials." Advanced Materials Research 485 (February 2012): 584–87. http://dx.doi.org/10.4028/www.scientific.net/amr.485.584.
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How to establish the bond-slip constitutive relation model of concrete and gypsum board will be of great academic significance. Through the pull-out experiment of CFFP, the load-slip curves is obtained. The characteristics and research situation of bond-slip performance at the inter face of concrete and other materials are introduced, and the bond-slip constitutive relation models are summarized at the same time. By using the fitting operation, the proposed constitutive relation is put forward , which is feasible and can be applied to further research on CFFP.
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Bjøntegaard, Ø., and E. J. Sellevold. "Interaction between thermal dilation and autogenous deformation in high performance concrete." Materials and Structures 34, no. 5 (2001): 266–72. http://dx.doi.org/10.1007/bf02482205.
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Liu, Qi, Wenfeng Du, Nasim Uddin, and Zhiyong Zhou. "Flexural Behaviors of Concrete/EPS-Foam/Glass-Fiber Composite Sandwich Panel." Advances in Materials Science and Engineering 2018 (October 21, 2018): 1–10. http://dx.doi.org/10.1155/2018/5286757.
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Composite structural insulated panels (CSIPs) have been developed for structural floor applications instead of traditional structural insulated panels (SIPs). However, the load bearing capacity of CSIPs is low due to the debonding between the top face sheet and the core when they are used for floors. To overcome this drawback, an improved composite structural insulated panel (ICSIP) was proposed and analyzed in this paper. In ICSIPs, a thick layer of concrete is used as the top face sheet instead of glass-fiber-reinforced polymer (GFRP) in CSIPs to increase the stiffness of the top compression face sheet. However, the bottom GFRP face sheet and EPS cores in CSIPs are preserved to reduce the weight of the structure and act as a template for the top concrete panels. Full-scale experimental testing and finite-element analysis were conducted to predict the flexural strength and deflection of the ICSIP floor member. Good agreement has been observed between the numerical results and experimental response up to the failure. The cause of failure of ICSIPs is the crushing of concrete face sheet rather than debonding. Moreover, the calculation formula for the ultimate bearing load and deflection was also developed based on the classical sandwich theory. The theoretical predictions reflect well the linear flexural response of the ICSIPs, while deviate as the load increases up to failure due to the theory limitations.
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Sharma, Raju, Jeong-Gook Jang, and Jong-Wan Hu. "Phase-Change Materials in Concrete: Opportunities and Challenges for Sustainable Construction and Building Materials." Materials 15, no. 1 (2022): 335. http://dx.doi.org/10.3390/ma15010335.
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The use of phase-change materials (PCM) in concrete has revealed promising results in terms of clean energy storage. However, the negative impact of the interaction between PCM and concrete on the mechanical and durability properties limits field applications, leading to a shift of the research to incorporate PCM into concrete using different techniques to overcome these issues. The storage of clean energy via PCM significantly supports the UN SDG 7 target of affordable and clean energy. Therefore, the present study focuses on three aspects: PCM type, the effect of PCM on concrete properties, and connecting the outcome of PCM concrete composite to the United Nations sustainable development goals (UN SDGs). The compensation of reduction in strength of PCM-contained concrete is possible up to some extent with the use of nanomaterials and supplementary cementitious materials. As PCM-incorporated concrete is categorized a type of building material, the large-scale use of this material will affect the different stages associated with building lifetimes. Therefore, in the present study, the possible amendments of the different associated stages of building lifetimes after the use of PCM-incorporated concrete are discussed and mapped in consideration of the UN SDGs 7, 11, and 12. The current challenges in the widespread use of PCM are lower thermal conductivity, the trade-off between concrete strength and PCM, and absence of the link between the outcome of PCM-concrete composite and UN SDGs. The global prospects of PCM-incorporated concrete as part of the effort to attain the UN SDGs as studied here will motivate architects, designers, practicing engineers, and researchers to accelerate their efforts to promote the consideration of PCM-containing concrete ultimately to attain net zero carbon emissions from building infrastructure for a sustainable future.
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Flatt, Robert J., Nicos Martys, and Lennart Bergström. "The Rheology of Cementitious Materials." MRS Bulletin 29, no. 5 (2004): 314–18. http://dx.doi.org/10.1557/mrs2004.96.
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AbstractThe introduction of a new generation of dispersants in concrete allow this material to exhibit self-compacting properties in its fresh state and high durability and mechanical strength in its hardened state. These properties translate into many practical advantages for the construction field.Two of the most important are reducing the ecological impact of this sector of industry and reducing the labor-intensive work associated with placing ordinary concrete by vibration. In this article, it will be shown that knowledge of colloidal science has proven essential in the development of this new generation of dispersants for concrete. Indeed, the polymer molecules used in these dispersants are specifically designed to induce steric repulsion between cement particles, reducing their agglomeration and allowing high workability of fresh concrete prior to setting. While the linkage between interparticle forces and the rheological behavior of cement pastes is still only semiquantitative, recent advances in the modeling of concrete rheology show very promising results in terms of handling aggregates with a wide distribution of particle sizes and shapes. However, accurate modeling requires reliable input on the interaction of the dispersant with the hydrating cement at the molecular level, which is identified as a future research challenge.
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Rakhimbaev, S. M., A. A. Logvinenko, and M. I. Logvinenko. "Mechanism of Interaction between Concrete Cement Matrix and Mineral Additive Particles." Materials Science Forum 992 (May 2020): 98–103. http://dx.doi.org/10.4028/www.scientific.net/msf.992.98.
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A nature of the forces, which act between the concrete cement matrix and entrained mineral particles (ground additives, fine and coarse additives), has been considered. It has been shown that the adhesion between them is attributable to the forces of different nature. The strongest adhesion between the particles of the hydrated binding material and mineral additives occurs, when materials, which react with calcium hydrate of the pore fluid, are used. The latter includes glassy wollastonite, which is part of granulated blast furnace slag. Even at a temperature of 25 °C, an aggressive interaction between them is observed and firm chemical bonds occur. In such case, the dissociation energy of such bonds ranges from 400 to 500 kJ per bond. Between materials, such as crystalline wollastonite and the concrete cement matrix, there is an epitaxial coalescence of its basal surfaces and tobermorite calcium hydrosilicates formed by the interaction of the binder with water. A direct contact is required between the reacting surfaces for such interaction. This is implemented by virtue of the bond, which is attributable to contraction forces resulting from shrinkage strains of the hydrated particles in the concrete cement matrix. Internal strains of the cement that are attributable to contraction, shrinkage, and carbonization of hydrated compounds result in the cement sheath contracting around the aggregate grains and steel reinforcement. Internal strains of the cement stone can be calculated using the Lame equation. We have reviewed the role of the factors, which are most critical for contraction of the cement ring around coarse particles of the aggregate and for stress-strain properties of artificial conglomerates, which have different composition and purpose.
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Grujić, Bojana, Igor Jokanović, Žarko Grujić, and Dragana Zeljić. "Numerical modelling of the reinforced concrete influence on a combined system of tunnel support." Selected Scientific Papers - Journal of Civil Engineering 12, no. 2 (2017): 63–70. http://dx.doi.org/10.1515/sspjce-2017-0020.
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Abstract The paper presents the experimental, laboratory determined rheological-dynamic analysis of the properties of fiber reinforced concrete, which was then utilized to show nonlinear analysis of combined system of tunnel support structure. According to the performed experiments and calculations, different processes of destructive behavior of tunnel lining were simulated in combination with elastic and elastic-plastic behavior of materials taking into account the tunnel loading, the interaction between the fiber reinforced concrete and soil, as well as the interaction between the fiber reinforced concrete and the inner lining of the tunnel.
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Vasudevan, Karthikgheyan, Hazril Sherney Basher, and Mohd Hafizal Mohd Isa. "THERMAL AND DAYLIGHTING PERFORMANCE OF TRANSPARENT CONCRETE IN PENANG, MALAYSIA." Malaysian Journal of Sustainable Environment June, no. 2023 (2023): 61–82. http://dx.doi.org/10.24191/myse.v0ijune.22673.
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Modern technology studies and research developments have enhanced the quality and innovation of concrete. Transparent concrete is concrete that has light-transmitting properties which transmit light through the optical fibre. Optical fibres are reinforced in the conventional concrete mixture from one face to another face, which allows direct light to transmit through it. Daylighting factor is one of the fundamental qualities of the energy efficiency of a building. The thermal performance is also crucial to providing comfort to the building occupants. The literature studies cover the light transmittance and thermal performance of transparent concrete. Selected literature studies are reviewed based on the related topic, Asian countries, and countries with a similar climate to Malaysia. This research applies quantitative method where it was focus on experimental study to transparent concrete. The overall result indicates improvement on light transmission and thermal performance as the plastic optical fibre increased compared to conventional concrete. The total average outdoor surface temperature of transparent concrete shows a difference of 0.989°C lower than conventional concrete. The total average temperature different between conventional concrete and transparent concrete (560 optical fibre) are 0.9°C. This experiment's significant contribution is that using more plastic fibre optic reduces thermal conductivity and heat gain while allowing for greater daylighting. Finally, transparent concrete shows effectiveness on light transmission and thermal resistance where it can contribute to building industry on green building and sustainable design. However, the further studies on thermal performance with longer duration is required to analyses the thermal heat loss.
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Yu, Jiahong, Xixiang Sun, Ying Huang, and Yige Jia. "Concrete or Abstract? The Impact of Green Advertising Appeals and Information Framing on Consumer Responses." Journal of Theoretical and Applied Electronic Commerce Research 20, no. 2 (2025): 130. https://doi.org/10.3390/jtaer20020130.
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Green advertising messages often face challenges of abstraction and outcome ambiguity. To address this, we apply the framing effect theory to explore how concrete versus abstract expressions in green advertising interact with consumer perceptions. Drawing on the Stereotype Content Model (SCM), we propose a congruence framework: concrete messages align with competence appeals, while abstract messages align with warmth appeals. Through two experiments, we demonstrate that such congruence significantly enhances green purchase intention. Experiment 1 establishes the interaction effect between message framing (concrete vs. abstract) and appeal type (competence vs. warmth), revealing that concrete–competence and abstract–warmth pairings outperform mismatched conditions. Experiment 2 further validates advertising attitudes as a mediator and product involvement as a moderator, clarifying boundary conditions. These findings advance the theoretical understanding of framing effects in sustainability communication and offer actionable strategies for marketers: aligning message specificity (concrete/abstract) with appeal dimensions (competence/warmth) can amplify consumer engagement, particularly when tailored to product contexts.
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Guo, Jun, and James V. Cox. "An Interface Model for the Mechanical Interaction between FRP Bars and Concrete." Journal of Reinforced Plastics and Composites 19, no. 1 (2000): 15–33. http://dx.doi.org/10.1177/073168440001900102.
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Mitarai, Osamu, Makoto Katsurai, Hitoshi Tamura, et al. "Magnetic interaction between a tokamak reactor and its reinforced-concrete building." Fusion Engineering and Design 146 (September 2019): 2057–61. http://dx.doi.org/10.1016/j.fusengdes.2019.03.101.
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Kujawa, Weronika, Iwona Tarach, Ewa Olewnik-Kruszkowska, and Anna Rudawska. "Effect of Polymer Additives on the Microstructure and Mechanical Properties of Self-Leveling Rubberised Concrete." Materials 15, no. 1 (2021): 249. http://dx.doi.org/10.3390/ma15010249.
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The materials based on concrete with an addition of rubber are well-known. The interaction between concrete components and rubber particles is in the majority cases insufficient. For this reason, different substances are introduced into concrete-rubber systems. The aim of this paper is to establish the influence of five different polymer additives, i.e., 1. an aqueous dispersion of a styrene-acrylic ester copolymer (silanised) (ASS), 2. water dispersion of styrene-acrylic copolymer (AS), 3. anionic copolymer of acrylic acid ester and styrene in the form of powder (AS.RDP), 4. water polymer dispersion produced from the vinyl acetate and ethylene monomers (EVA), 5. copolymer powder of vinyl acetate and ethylene (EVA.RDP)) on the properties of the self-leveling rubberised concrete. Scanning electron microscopy has allowed to establish the interaction between the cement paste and rubber aggregates. Moreover, the compressive strength and flexural strength of the studied materials were evaluated. The results indicate that the mechanical properties depend extensively on the type as well as the amount of the polymer additive introduced into the system.
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Li, Dejie, Chong Shi, Huaining Ruan, and Bingyi Li. "Shear Characteristics of Soil—Concrete Structure Interaction Interfaces." Applied Sciences 12, no. 18 (2022): 9145. http://dx.doi.org/10.3390/app12189145.
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The shear characteristics of the interfaces between soil and concrete structures are essential for the safety of the structures. In this study, a large-scale direct shear test apparatus was developed to measure the mechanical parameters of soil–concrete interfaces under conditions with different soil types, soil moisture contents, and interfacial filling materials. The results showed that the shear stress of the soil–concrete interface increased initially and then became stable with the increase in the shear displacement. The shear displacement of the sandy soil when the shear stress became stable was smaller than that of the clayey soil. The silty sand–concrete interface had a smaller friction angle than the interface with the medium-coarse sand. Moreover, with the increase in the soil moisture content, the friction angle of the clayey soil–concrete interface decreased rapidly, whereas the cohesion first increased and then decreased, and the peak cohesion was near the plastic limit of the soil. Under the same moisture content, the friction angle and cohesion of the clay–concrete interface was reduced by filling the interface with a thin layer of sandy soil, while filling the silty sand–concrete interface with a thin layer of silt reduced the friction angle and increased the interfacial cohesion. Nonetheless, the filling had little impact on the overall shear strength of the interface.
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Zhang, Yufang, Jian Li, Hongyu Liu, Wei Li, Jiaming Li, and Lijie Hou. "Research on the Interaction Mechanism between Landslide and Tunnel Engineering." Advances in Materials Science and Engineering 2021 (November 27, 2021): 1–14. http://dx.doi.org/10.1155/2021/2265459.
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The landslide at the entrance of a railway tunnel is large scale, and serious diseases are prone to appear under natural disasters, which threaten the safety of the tunnel. According to its characteristics, on-site long-term monitoring experiments and numerical analysis were carried out, and the mechanism of interaction between landslide and tunnel engineering was analyzed. The results show that under the impact of rainfall and earthquake, the original internal stress balance in the landslide body is disturbed, leading to the increase in landslide thrust and damage of the tunnel lining. Simultaneously, the excavation of the tunnel can slack the surrounding rock to increase the landslide thrust and make the landslide be finally formed; this landslide conversely acts on the tunnel, resulting in deformation and destruction of the tunnel. During the monitoring, under the influence of rainfall and earthquake, the stress of the secondary lining was continuously increased by 25%. Tunnel construction caused a maximum deformation of 30 mm in the antislide pile at a distance of 2.12 m, and the slope and the tunnel were also affected. Under extreme conditions such as rainfall and earthquake, shear failure occurred at the vault, bottom, and waist of the right-line tunnel located at the junction of soil and rock; at this time, the tensile strength of the tunnel reached 93.8% of the limit value of concrete, which seriously affected the safety of the tunnel. As for the weakened tunnel structure, measures such as dense planting and strengthening of concrete strength should be adopted to enhance the safety of the tunnel structure.
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Velychkovych, Andrii, Liubomyr Ropyak, and Olga Dubei. "Strength Analysis of a Two-Layer PETF-Concrete Column with Allowance for Contact Interaction between Layers." Advances in Materials Science and Engineering 2021 (September 23, 2021): 1–10. http://dx.doi.org/10.1155/2021/4517657.
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This article develops an idea of mechanical recycling of polymer wastes. Unlike previous research studies, which are dedicated to the study of the physical and mechanical properties of fibrous concrete and the technology of its manufacturing, this work considers a specific construction product—laminated concrete column made of recycled polyethylene terephthalate (PETF). Currently, there are no policy documents (standards or codes) regarding the engineering design of such constructions. Therefore, the authors’ attention is focused on mechanical and mathematical modeling of the laminated column behavior under operational load. An analytical study of two-layer PETF-concrete column’s stress-strain state was performed, taking into account the contact interaction between inhomogeneous layers of the materials. It has been determined that, in certain circumstances, the contact pressure between the layers can have a significant effect on the load-bearing capacity of the column. In general, a method of engineering assessment of laminated columns’ load-bearing capacity was developed.
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Carrara, Pietro, Tao Wu, Roland Kruse, and Laura De Lorenzis. "Towards multiscale modeling of the interaction between transport and fracture in concrete." RILEM Technical Letters 1 (December 21, 2016): 94. http://dx.doi.org/10.21809/rilemtechlett.2016.21.
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Transport, fracture and their interaction in concrete are complex phenomena of great practical relevance for the durability of civil engineering structures. Due to the heterogeneous nature of the materials, encompassing a wide range of length scales, multiscale approaches are essential. In this paper, we outline some recent research results and open issues in this field. First, we present a microscale model which aims at simulating chloride diffusion and binding in cement. Then, we outline a mesoscale model addressing coupling between cracking and diffusion. Finally, we discuss open issues in the acquisition of the mesoscale geometry from X-ray computed tomography techniques.
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Mottl, Martin, Pavel Reiterman, and Jiří Pazderka. "The Influence of Aggressive Environmental Conditions on the Adhesion of Applied Crystalline Materials." Journal of Composites Science 8, no. 1 (2023): 5. http://dx.doi.org/10.3390/jcs8010005.
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Crystalline coatings are waterproofing systems used for additional protection against increased moisture and subsurface water ingress. Even though these crystalline materials are commonly used in moisture-protective systems, they have not yet been sufficiently scientifically described. The weakest link in the chain of interaction between crystalline coatings and underlying concrete is the transition zone. To increase knowledge of the interaction between these materials, a series of experiments was prepared using a specially formulated protective mortar as the final surface layer, with the function of additionally waterproofing the structure. An experimental study of the adhesion of surface layers based on secondary crystallization to provide additional protection to concrete structures loaded with moisture or ground water exposure is presented in this paper. The series of experiments carried out consisted of an analysis of protective crystalline mortar adhesion to concrete samples of identical composition. A set of experimental measurements under the influence of various boundary conditions was carried out to determine the bond strength between two different materials. For the experimental measurements, the materials were exposed to aggressive environments for which durability verification had not yet been performed. A modified protective mortar with crystalline admixture was used as an overlayed material. This mortar worked similarly to a crystalline coating after application. Over time, there was penetration of the underlaying concrete and a secondary hydration of the cement matrix which resulted in the waterproofing of the structure. The test samples were exposed to aggressive environmental conditions in the form of freezing–thawing cycles and a carbonation process. Pull-off tests were carried out on every test sample to determine the strength of the surface layers. The penetration of the crystalline agent into the base concrete was confirmed with an SEM observation. The results of the experimental program showed that exposure to the aggressive environment further reduced the strength of the modified mortar containing the crystalline admixture. However, the bond strength between the concrete and the modified mortar exceeded the tensile strength of the concrete.
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Jaffar, Mohd Isa, Wan Hamidon Wan Badaruzzaman, Mohd Mustafa Al Bakri Abdullah, and Rafiza Abd Razak. "Comparative Study Floor Flexural Behavior of Profiled Steel Sheeting Dry Board between Normal Concrete and Geopolymer Concrete In-Filled." Applied Mechanics and Materials 754-755 (April 2015): 364–68. http://dx.doi.org/10.4028/www.scientific.net/amm.754-755.364.
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This study investigates the behavior of in-filled materials of profiled steel sheeting dry board (PSSDB) floor system. Two tests were conducted, namely, push-out test to know the connection stiffness and bending test on the PSSDB panel under the influence of different in-filled materials. Result of the push-out test shows that the connection stiffness of the geopolymer concrete-filled PSSDB is 331% higher than that of PSSDB that is filled with normal concrete. This connection stiffness contributed to the reduction of deflection value of 21% in the middle of the midspan for full-board geopolymer concrete in-filled panel bending test. This phenomenon triggered the increase of interaction within the composite system, making the panel that is filled with the geopolymer concrete 25% stronger than the normal concrete–filled panel.
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Wan-Wendner, Roman, Christian Carloni, Jia-Liang Le, and Gianluca Cusatis. "Fracture & Deterioration: Interaction between Fracturing, Scaling, Aging, and Deterioration Phenomena in Concrete Structures." Engineering Fracture Mechanics 202 (October 2018): 508. http://dx.doi.org/10.1016/j.engfracmech.2018.10.013.
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Trejbal, Jan, Václav Nežerka, Radim Hlůžek, and Zdeněk Prošek. "MECHANICAL PROPERTIES IMPROVEMENT OF FIBER REINFORCED CONCRETE." Acta Polytechnica CTU Proceedings 22 (July 25, 2019): 123–27. http://dx.doi.org/10.14311/app.2019.22.0123.
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Fiber reinforced concrete mechanical properties are limited due to low adhesion between polymer fibers and cement matrix. To ensure a strong interaction between the two materials, polypropylene fibers (d = 0.305mm) were modified by an oxygen plasma treatment. The interface interaction was moreover activated using finely ground concrete recyclate, whose individual grains (1−64 μm) ensure an adhesion improvement in interfacial zones. The adhesion enhancement was verified by pull-out tests, when reference and modified fibers were pulled-out from cement matrix specimens. Such obtained results were used as a crucial parameter to numerical simulations of bending tests of specimens (550 × 150 × 150mm) with properties following fiber reinforced concrete. It was shown that samples reinforced with modified fibers and contained activating recyclate reached on higher residual bending strength then those with reference fibers.
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Han, Weiwei, Panpan Tian, Yigang Lv, Chaosheng Zou, and Tao Liu. "Long-Term Prestress Loss Calculation Considering the Interaction of Concrete Shrinkage, Concrete Creep, and Stress Relaxation." Materials 16, no. 6 (2023): 2452. http://dx.doi.org/10.3390/ma16062452.
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In order to accurately calculate the long-term prestress losses of prestressed tendons, a time-varying model of long-term prestress loss considering the interaction between concrete shrinkage, creep, and the stress relaxation of prestressed tendons was constructed. Then, a method for calculating the long-term prestress losses of concrete structures was developed. A long-term prestress loss test of a prestressed concrete T-beam in a long-term field test environment was carried out. The measured values of long-term prestress losses are compared with the calculated results of JTG 3362-2018, AASHTO LRFD-2007, and the time-varying law model. The results show that the long-term effective tension of the T-beam decreases gradually with the increase in the load holding time. At the beginning of loading, the tensile force changes rapidly and then gradually slows down. The later the tensile age or the higher the initial loading stress level, the smaller the long-term prestress losses of the prestressed tendons. The long-term prestress loss values calculated by JTG 3362-2018, AASHTO LRFD-2007, and the time-varying law model increase with the increase in the load holding time. In the early stage of loading, the rate of change slows down and tends to be stable. The calculated results of JTG 3362-2018 and AASHTO LRFD-2007 are significantly different from the measured values. However, the calculated results of the time-varying law model are in good agreement with the measured values. The average coefficients of variation of the long-term prestress loss calculated by JTG 3362-2018, AASHTO LRFD-2007, and the time-varying law model are 17%, 10%, and 5%, respectively. The time-varying law model of the long-term prestress losses of prestressed tendons is accurate, and the long-term prestress loss of prestressed reinforcement can be predicted effectively.
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Gago, Filip, Ján Mihálik, Soňa Masarovičová, Jozef Vlček, Vojtěch Boltnar, and Lukáš Uličný. "Large Scale Shear Box Testing of Interface Between Construction Materials and Soils." Civil and Environmental Engineering 19, no. 2 (2023): 724–29. http://dx.doi.org/10.2478/cee-2023-0065.
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Abstract The interaction between soil and building structures of various materials is defined on the basis of certain assumptions, but these are shown in many cases to be not accurate from the point of view of safe, reliable and economic design of engineering structures. Therefore, as part of our research activities, we decided to better understand the transfer of shear forces and the interaction between soil and other materials. We focused on testing materials in a shear box apparatus, where 3 types of tests were carried out: in the first stage, we tested the shear parameters of the soil in a 900 mm2 box apparatus; in the second stage, the properties of the interaction between soil and concrete were tested, and in the third stage, soil was in contact with the steel plate. The results of the tests are within the expected range of the interface friction angle between the structures and the soils.
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Sahibulla, S. M. Mohamed. "The Consistency, Setting Time and Compression Strength of Pozzolanic Materials: A Taguchi Gray Validation." Journal of Cement Based Composites 3, no. 1 (2022): 1–7. http://dx.doi.org/10.36937/cebacom.2022.5627.
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Currently, the focus of research is on biocement mortar and concrete. To lower the cement substance by up to 40%, lime, fly ash, metakaolin, and silica fume are utilised. The major purpose of this study was to see if adding pozzolanic materials to biocement mortar may increase its setting time, consistency, and compressive strength, as well as the interaction of these pozzolanic components with cement mortar and concrete. The pozzolanic particles by sieving interaction to affirm the uniform molecule size equivalent to 1 µm. The compressive strength, consistency, and final setting time were estimated after the fruitful maturing of concrete blocks for around 28 days. As indicated by Taguchi investigation, the exploratory arrangement Level 10 gives the general best position among other trial designs with the GRG of 0.805. Besides, the weight level of metakaolin straightforwardly impacts the general exhibition of concrete substantial shapes rather than silica smoke, lime, and fly debris particles. The affirmation concentrates on uncovered improvement in the dark social grade of 1.92%, which is equivalent to the high compressive strength of 51.285 MPa, consistency territory between 29.5 to 38.5, and final setting time is 525 min. the impact of different pozzolanic substances on the concrete's consistency and setting time. It uncovered that by supplanting the 40% normal Portland concrete (OPC) with bio concrete, the concrete's consistency improves and the level of pozzolanic materials comparative with the level of OPC can build the concrete consistency restricts and lessen the use of bio concrete with minimal expense.
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Elgamal, Ahmed, and Nissreen Elfaris. "Seismic Isolation Materials for Bored Rock Tunnels: A Parametric Analysis." Infrastructures 9, no. 3 (2024): 44. http://dx.doi.org/10.3390/infrastructures9030044.
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Most recent tunnel designs rely on more thorough analyses of the intricate rock interactions. The three principal techniques for excavating rock tunneling are drill-and-blast for complete or partial cross-sections, TBM only for circular cross-sections with full faces, and road header for small portions. Tunnel-boring machines (TBM) are being utilized to excavate an increasing number of tunnels. Newer studies have demonstrated that subterranean structures such as tunnels produce a variety of consequences during and after ground shaking, challenging the long-held belief that they are among the most earthquake-resistant structures. Consequently, engineering assessment has become crucial for these unique structures from both the geotechnical and structural engineering standpoints. The designer should evaluate the underground structure’s safety to ensure it can sustain various applied loads, considering both seismic loads and temporary and permanent static loads. This paper investigates how adding elastic, soft material between a circular tunnel and the surrounding rock affects seismic response. To conduct the study, Midas/GTS-NX was used to model the TBM tunnel and the nearby rock using the finite element (F.E.) method to simulate the soil–tunnel interactions. A time–history analysis of the El Centro (1940) earthquake was used to calculated the stresses accumulated in the tunnels during seismic episodes. Peak ground accelerations of 0.10–0.30 g, relative to the tunnel axis, were used for excitation. The analysis utilized a time step of 0.02 s, and the duration of the seismic event was set at 10 s. Numerical models were developed to represent tunnels passing through rock, with the traditional grout pea gravel vs. isolation layer. A parametric study determined how isolation material characteristics like shear modulus, Poisson’s ratio, and unit weight affect tunnel-induced stresses. In the meantime, this paper details the effects of various seismic isolation materials, such as geofoam, foam concrete, and silicon-based isolation material, to improve protection against seismic shaking. The analysis’s findings are discussed, and how seismic isolation affects these important structures’ performance and safety requirements is explained.