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Journal articles on the topic 'Aggregates (Building materials) – Expansion and contraction'

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Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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1

Faye, Khemendra. "Review Paper on Comparative Study of RCC Framed Building with and Without Expansion Joint at Different Location." International Journal for Research in Applied Science and Engineering Technology 10, no. 1 (January 31, 2022): 986–89. http://dx.doi.org/10.22214/ijraset.2022.39934.

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Abstract: The pounding responses of the expansion joint in a curved ramp bridge under earthquake conditions. Long term effects of such seasonal temperature changes develop stresses and deformation in the building. Concrete creep and shrinkage increase the cracks widths and stresses. For elimination of this expansion joints are provided. The temperature expansion occurred most significantly during 20°C to 40°C and the optimised gradation could alleviate the arch expansion effectively, in the range of 20°C to 30°C. An expansion joint is a gap provided in the structure to allow expansion and contraction of the building due to temperature changes. It absorbs the heat-induced by expansion and contraction of various construction materials. Two theoretical models were used under eight types of seismic conditions. Results indicate that a curved ramp bridge without an abutment expansion joint is a favorable structure for seismic design. Keywords: Earthquake, pounding, Seismic Analysis, Expansion joints, Thermal stresses, Concrete Creep.
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2

Sibbick, R. G., and C. L. Page. "Threshold alkali contents for expansion of concretes containing British aggregates." Cement and Concrete Research 22, no. 5 (September 1992): 990–94. http://dx.doi.org/10.1016/0008-8846(92)90123-d.

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3

Menéndez, E., R. García-Roves, B. Aldea, E. Puerto, and H. Recino. "Study of the alkali-silica reaction rate of Spanish aggregates. Proposal of a classification based in accelerated mortar bars tests and petrographic parameters." Materiales de Construcción 71, no. 344 (December 1, 2021): e263. http://dx.doi.org/10.3989/mc.2021.13421.

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The alkali-silica reaction has been studied in depth due to the evolution in the knowledge of the expansive phenomenon. One of its most important aspects is the reaction rate of the aggregates. In Spain, at the early 90s of the 20th century, aggregates were considered almost non-reactive. However, the use of accelerated curing and other environmental factors revealed that there were potentially reactive siliceous aggregates. Nevertheless, there are several siliceous and limestone aggregates with siliceous inclusions that show reactivity over long period. In the present work, open porosity, expansion and petrography with quartz reactivity index have been determined, in 68 siliceous, limestone and dolomitic aggregates, from quarries located in areas with diagnostic reactivity. Based on these parameters and their interrelation, a classification method is proposed to detect slow-reacting aggregates.
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4

Rivera, J. F., A. Orobio, R. Mejía de Gutiérrez, and N. Cristelo. "Clayey soil stabilization using alkali-activated cementitious materials." Materiales de Construcción 70, no. 337 (February 13, 2020): 211. http://dx.doi.org/10.3989/mc.2020.07519.

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In this study, a clayey soil classified as A-7-5 according ASTM D3282, was stabilized using alkali-activated cementitious materials (AAC) added to the soil dry in percentages of 20 and 30%. Fly ash (F1, F2) with high unburned carbon content (up to 38.76%), hydrated lime (L) and granulated blast furnace slag were used. Unconfined compressive strength and flexural strength at 28 days of curing and the durability after 12 wetting-drying cycles were evaluated. The results were compared with a soil-cement reference mixture. The soil treated with AAC-F1L showed a volume expansion of 0.51% and volume contraction of -0.57% compared with the 0.59% expansion and -0.68% contraction of the soil-cement reference mixture. Additionally, the mass loss after the wetting and drying cycles is only 3.74% which is slightly lower than the mass loss of the soil stabilized with ordinary Portland cement (OPC) (3.86%) and well below the value specified in Colombian regulations (7%).
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5

Prinčič, Tina, Petra Štukovnik, Stane Pejovnik, Geert De Schutter, and Violeta Bokan Bosiljkov. "Observations on dedolomitization of carbonate concrete aggregates, implications for ACR and expansion." Cement and Concrete Research 54 (December 2013): 151–60. http://dx.doi.org/10.1016/j.cemconres.2013.09.005.

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6

Amziane, Sofiane, and Mohammed Sonebi. "Overview on Biobased Building Material made with plant aggregate." RILEM Technical Letters 1 (June 2, 2016): 31. http://dx.doi.org/10.21809/rilemtechlett.2016.9.

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Global warming, energy savings, and life cycle analysis issues are factors that have contributed to the rapid expansion of plant-based materials for buildings, which can be qualified as environmental-friendly, sustainable and efficient multifunctional materials. This review presents an overview on the several possibilities developed worldwide about the use of plant aggregate to design bio-based building materials. The use of crushed vegetal aggregates such as hemp (shiv), flax, coconut shells and other plants associated to mineral binder represents the most popular solution adopted in the beginning of this revolution in building materials. Vegetal aggregates are generally highly porous with a low apparent density and a complex architecture marked by a multi-scale porosity. These geometrical characteristics result in a high capacity to absorb sounds and have hygro-thermal transfer ability. This is one of the essential characteristics which differ of vegetal concrete compared to the tradition mineral-based concretes. In addition, the high flexibility of the aggregates leads to a non-fragile elasto-plastic behavior and a high deformability under stress, lack of fracturing and marked ductility with absorbance of the strains ever after having reached the maximum mechanical strength. Due to the sensitivity to moisture, the assessment of the durability of vegetal concrete constitutes one of the next scientific challenging of bio-based building materials.
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7

Amziane, Sofiane, and Mohammed Sonebi. "Overview on Biobased Building Material made with plant aggregate." RILEM Technical Letters 1 (June 2, 2016): 31. http://dx.doi.org/10.21809/rilemtechlett.v1.9.

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Global warming, energy savings, and life cycle analysis issues are factors that have contributed to the rapid expansion of plant-based materials for buildings, which can be qualified as environmental-friendly, sustainable and efficient multifunctional materials. This review presents an overview on the several possibilities developed worldwide about the use of plant aggregate to design bio-based building materials. The use of crushed vegetal aggregates such as hemp (shiv), flax, coconut shells and other plants associated to mineral binder represents the most popular solution adopted in the beginning of this revolution in building materials. Vegetal aggregates are generally highly porous with a low apparent density and a complex architecture marked by a multi-scale porosity. These geometrical characteristics result in a high capacity to absorb sounds and have hygro-thermal transfer ability. This is one of the essential characteristics which differ of vegetal concrete compared to the tradition mineral-based concretes. In addition, the high flexibility of the aggregates leads to a non-fragile elasto-plastic behavior and a high deformability under stress, lack of fracturing and marked ductility with absorbance of the strains ever after having reached the maximum mechanical strength. Due to the sensitivity to moisture, the assessment of the durability of vegetal concrete constitutes one of the next scientific challenging of bio-based building materials.
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8

Neuendorf, Talika A., Niclas Weigel, Michelle Vigogne, and Julian Thiele. "Additive Soft Matter Design by UV-Induced Polymer Hydrogel Inter-Crosslinking." Gels 8, no. 2 (February 14, 2022): 117. http://dx.doi.org/10.3390/gels8020117.

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In recent years, stimuli-responsive hydrogels have gained tremendous interest in designing complex smart 4D materials for applications ranging from biomedicine to soft electronics that can change their properties on demand over time. However, at present, a hydrogel’s response is often induced by merely a single stimulus, restricting its broader applicability. The controlled hierarchical assembly of various hydrogel building blocks, each with a tailored set of mechanical and physicochemical properties as well as programmed stimulus response, may potentially enable the design and fabrication of multi-responsive polymer parts that process complex operations, like signal routing dependent on different stimuli. Since inter-connection stability of such building blocks directly accompanies the transmission of information across building blocks and is as important as the building property itself to create complex 4D materials, we provide a study on the utility of an inter-crosslinking mechanism based on UV-induced 2,3-dimethylmaleimide (DMMI) dimerization to inter-connect acrylamide-based and N-isopropylacrylamide-based millimeter-sized cubic building blocks, respectively. The resulting dual-crosslinked assemblies are freestanding and stable against contraction–expansion cycles in solution. In addition, the approach is also applicable for connecting microfluidically fabricated, micrometer-sized hydrogel spheres, with the resulting assemblies being processable and mechanical stable, likewise resisting contraction–expansion in different solvents, for instance.
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9

Mehta, PK, CA Rogers, and RD Hooton. "Reduction in Mortar and Concrete Expansion with Reactive Aggregates Due to Alkali Leaching." Cement, Concrete and Aggregates 13, no. 1 (1991): 42. http://dx.doi.org/10.1520/cca10548j.

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10

Juenger, M. C. G., and C. P. Ostertag. "Influence of synthetic aggregates on expansion due to alkali–silica reaction." Magazine of Concrete Research 57, no. 6 (August 2005): 331–37. http://dx.doi.org/10.1680/macr.2005.57.6.331.

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11

Zhu, Huiying, Wen Chen, Wei Zhou, and Ewan A. Byars. "Expansion behaviour of glass aggregates in different testing for alkali-silica reactivity." Materials and Structures 42, no. 4 (July 23, 2008): 485–94. http://dx.doi.org/10.1617/s11527-008-9396-4.

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12

Islam, Md Rashadul, and Rafiqul A. Tarefder. "Coefficients of Thermal Contraction and Expansion of Asphalt Concrete in the Laboratory." Journal of Materials in Civil Engineering 27, no. 11 (November 2015): 04015020. http://dx.doi.org/10.1061/(asce)mt.1943-5533.0001277.

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13

Shi, Caijun. "Corrosion of Glasses and Expansion Mechanism of Concrete Containing Waste Glasses as Aggregates." Journal of Materials in Civil Engineering 21, no. 10 (October 2009): 529–34. http://dx.doi.org/10.1061/(asce)0899-1561(2009)21:10(529).

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14

Mukhopadhyay, Anal K., and Dan G. Zollinger. "Development of Dilatometer Test Method to Measure Coefficient of Thermal Expansion of Aggregates." Journal of Materials in Civil Engineering 21, no. 12 (December 2009): 781–88. http://dx.doi.org/10.1061/(asce)0899-1561(2009)21:12(781).

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15

Khmurovska, Yuliia, and Petr Štemberk. "RBSM-based model for prediction of radiation-induced volumetric expansion of concrete aggregates." Construction and Building Materials 294 (August 2021): 123553. http://dx.doi.org/10.1016/j.conbuildmat.2021.123553.

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16

Gorospe, Karla, Emad Booya, Hossein Ghaednia, and Sreekanta Das. "Effect of various glass aggregates on the shrinkage and expansion of cement mortar." Construction and Building Materials 210 (June 2019): 301–11. http://dx.doi.org/10.1016/j.conbuildmat.2019.03.192.

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17

Moreno-Maroto, José Manuel, Carlos Javier Cobo-Ceacero, Manuel Uceda-Rodríguez, Teresa Cotes-Palomino, Carmen Martínez García, and Jacinto Alonso-Azcárate. "Unraveling the expansion mechanism in lightweight aggregates: Demonstrating that bloating barely requires gas." Construction and Building Materials 247 (June 2020): 118583. http://dx.doi.org/10.1016/j.conbuildmat.2020.118583.

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18

Žurauskienė, Ramunė, and Marina Valentukevičienė. "Experimental Research on Quality Parameters of Recycled Concrete." Materials 13, no. 11 (June 3, 2020): 2538. http://dx.doi.org/10.3390/ma13112538.

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Concrete itself, and issues relating to the recycling and management of reinforced concrete waste, are highly relevant, especially when urban expansion is being achieved by increased building construction volumes. This research investigates concrete waste and its (re)usage possibilities and resolves several major issues related to the question of how natural materials can be replaced by compounds made from concrete waste, thereby saving natural resources. The experiment was carried out using concrete mixtures, which were combined with natural aggregates and crushed concrete waste (fraction 4/16). The resulting mix of concrete was achieved using natural aggregates, thus replacing natural aggregates with waste, which had partially and fully replaced bulky aggregates with crushed concrete waste. The main aim of the investigation was to investigate how aggregates made from crushed concrete waste impact the properties of concrete. The exothermic effect on the concrete mixture during the hardening process was investigated. Furthermore, a macrostructural analysis of hardened concrete was conducted using scanned sample images; the adhesion zone between newly formed concrete stone and aggregates derived from natural rock from crushed concrete waste was investigated. Using an electron microscope to observe aggregate from crushed concrete waste and the contact zone of hardened cement stone revealed that the aggregate from waste adheres poorly with hardened cement stone. Furthermore, both the mechanical properties of new, hardened concrete and determined resistance to frost indicators are weak. Concrete density and compression strength decreased (by up to 8% and up to 18%, respectively), and absorption increased almost twofold due to aggregates derived from crushed concrete waste, since their cleavage strength indicator was twice as high, while water absorption was four times higher than that of natural aggregate. The results indicate that recycled concrete obtained from demolished buildings is environmentally sustainable and can be recommended for lower quality concrete for use in related engineering projects.
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19

Liu, Hao, and Xiao Ming Du. "Genetic Analysis and Treatment of Cracks in the Residential Construction." Advanced Materials Research 671-674 (March 2013): 488–91. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.488.

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In the modern construction process, the wall cracks in residential buildings in the more general question, which the concrete cracks. Concrete cracks caused by a variety of reasons, such as temperature changes, uneven ground subsidence, wall expansion and contraction, there are some cracks by external effects or conservation measures is wrong or some chemical reaction causing the problem. In this paper, architectural design, building materials, construction and other aspects to analyze and propose some solutions approach.
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20

Naik, Tarun R., Rudolph N. Kraus, and Rakesh Kumar. "Influence of Types of Coarse Aggregates on the Coefficient of Thermal Expansion of Concrete." Journal of Materials in Civil Engineering 23, no. 4 (April 2011): 467–72. http://dx.doi.org/10.1061/(asce)mt.1943-5533.0000198.

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21

Zhang, Huan, Peiyao Sheng, Jizhi Zhang, and Zhong Ji. "Realistic 3D modeling of concrete composites with randomly distributed aggregates by using aggregate expansion method." Construction and Building Materials 225 (November 2019): 927–40. http://dx.doi.org/10.1016/j.conbuildmat.2019.07.190.

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22

Rodríguez, A., I. Santamaría-Vicario, V. Calderón, C. Junco, and J. García-Cuadrado. "Study of the expansion of cement mortars manufactured with Ladle Furnace Slag LFS." Materiales de Construcción 69, no. 334 (April 3, 2019): 183. http://dx.doi.org/10.3989/mc.2019.06018.

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Industrial by-products generated in the steel manufacturing are successfully used as raw materials in the production of construction materials. However, steel slags, due to their nature and composition, can cause undesirable side-effects in mortars and concretes. The reactive components of LFS and EAFS can affect the stability of the cement matrix. This situation may be prevented by an adequate pre-treatment of slag stabilization and a study of the possible reactions within its mineralogical components, to ensure the stability of the slag over time. In this work, an experimental process is shown to evaluate the behaviour of LFS under adverse environmental conditions when used as aggregates in the manufacture of cement mortars for masonry, such as the presence of humidity, high temperatures (80°C) and possible alkali-silica and alkali-silicate reactions. The results show an acceptable behaviour under normal environmental conditions (20°C). However, the formation crystalline acicular structures were observed under high temperatures (80°C) and in the presence of humidity, which degraded the internal structure of the mortars manufactured with LFS.
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23

Li, Yongchang, Hao Wu, Qin Fang, and Yong Peng. "A note on the impact resistance of concrete target against rigid projectile." International Journal of Protective Structures 9, no. 3 (April 2, 2018): 397–411. http://dx.doi.org/10.1177/2041419618763867.

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Concrete is an inhomogeneous cementitious composite which mainly consists of the cement matrix and the random distributed coarse aggregates. As for the most widely used construction materials of the protective structures designed to withstand the intentional or accidental impact loadings caused by high-speed projectiles, the impact resistance of concrete target against the rigid projectile impact is mainly dependent on the mass, density, impact velocity, diameter, and nose shape of the projectile, as well as strength and density of the target, and hardness and size of the coarse aggregates. However, the above influential parameters are not sufficiently considered in the existing cavity expansion–based model and constant resistance model for predicting the depth of penetration of a projectile. In this article, the influences of the hardness and size of the coarse aggregates on the depth of penetration are examined through the existing experimental data, and an improved rigid projectile penetration model for concrete target is proposed and validated by 19 sets of ogive- and flat-nosed projectile penetration tests.
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24

Mao, Wenting, Chunpeng Cao, Xincheng Li, Jueshi Qian, and Chao You. "Preparation of Magnesium Ammonium Phosphate Mortar by Manufactured Limestone Sand Using Compound Defoaming Agents for Improved Strength and Impermeability." Buildings 12, no. 3 (February 24, 2022): 267. http://dx.doi.org/10.3390/buildings12030267.

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Magnesium ammonium phosphate cement (MAPC) mortar has recently risen up as high performance rapid repair material for concrete structures. But high costs of the raw materials limit its restoration and maintenance projects on a wide application range. This study proposes the use of manufactured limestone sand with lower cost and wider range of sources in replacement of quartz sand as fine aggregates to produce MAPC mortar. However, the limestone fines of manufactured sand were initially found to have negative effects on the performance of MAPC mortar, causing significant blistering and volume expansion and decreased compressive strength and interfacial bonding strength. To minimize these negative effects, polyether modified silicone (PMS) defoamer and its compound use with mineral admixtures Portland cement and silica fume were investigated on the effectiveness in reducing expansion and improving other properties of MAPC mortar. Results showed that the compound use of PMS defoamer and Portland cement as a new defoaming formula effectively reduced the volume expansion from 7.92% to 0.91%. The compressive strength and interfacial bonding strength were significantly improved by over 34% and 60% respectively. Moreover, this defoaming formula showed improvements in water-tight performance and resistance to chloride penetration. According to the mercury intrusion porosimetry (MIP) analysis, the total porosity of MAPC mortar after defoaming treatment was decreased by about 40% and the pore structure was also modified to be finer by significantly reducing the harmful macropores. Overall, the use of manufactured limestone sands as fine aggregates turned out to be a feasible and economic approach for promoting the filed application of MAPC mortar.
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25

Moundoungou, I., D. Bulteel, E. Garcia-Diaz, V. Thiéry, P. Dégrugilliers, and J. G. Hammerschlag. "Reduction of ASR expansion in concretes based on reactive chert aggregates: Effect of alkali neutralisation capacity." Construction and Building Materials 54 (March 2014): 147–62. http://dx.doi.org/10.1016/j.conbuildmat.2013.12.036.

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26

Martínez, Juan Daniel, Santiago Betancourt-Parra, Ivonne Carvajal-Marín, and Mariluz Betancur-Vélez. "Ceramic light-weight aggregates production from petrochemical wastes and carbonates (NaHCO3 and CaCO3) as expansion agents." Construction and Building Materials 180 (August 2018): 124–33. http://dx.doi.org/10.1016/j.conbuildmat.2018.05.281.

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27

Hobbs, D. W. "A discussion of the paper “threshold alkali contents for expansion of concretes containing British aggregates” by R.G. Sibbick and C.L. Page." Cement and Concrete Research 23, no. 2 (March 1993): 495–97. http://dx.doi.org/10.1016/0008-8846(93)90120-x.

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28

Sibbick, R. G., and C. L. Page. "A reply to the discussion by D.W. Hobbs of the paper “threshold alkali contents for expansion of concretes containing British aggregates”." Cement and Concrete Research 23, no. 2 (March 1993): 498–99. http://dx.doi.org/10.1016/0008-8846(93)90121-o.

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29

Borchers, I., J. Lindgård, and C. Müller. "Evaluation of laboratory test methods for assessing the alkali-reactivity potential of aggregates by field site tests." Materiales de Construcción 72, no. 346 (June 1, 2022): e286. http://dx.doi.org/10.3989/mc.2022.17221.

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Field site tests were carried out to assess the reliability of the tests developed by RILEM and some regional tests to evaluate the alkali-reactivity potential of aggregates (eight tests were included). One hundred concrete cubes made with 13 different European aggregate combinations were stored on eight different European field sites to compare their expansions with the laboratory test results. All highly reactive aggregate combinations caused significant expansion of concrete cubes within the first six years on all field sites from Norway to Spain. These and the non-reactive aggregate combinations were correctly identified with all laboratory tests. Concrete cubes with moderately reactive aggregate combinations expanded very slowly and mainly in the outdoor exposure sites with warm climate conditions. The RILEM test method AAR-4.1 (60°C accelerated concrete prism test) and the Norwegian concrete prism test at 38°C seem to be best suited to identity the potential reactivity of moderately reactive aggregate combinations.
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30

Kovalchuk, O., and V. Zozulunets. "Use of active aggregates in concrete as a guarantee of expansion of raw material base and reduction of cost of products." Ways to Improve Construction Efficiency 1, no. 48 (June 24, 2021): 100–107. http://dx.doi.org/10.32347/2707-501x.2021.48(1).100-107.

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Traditional natural materials (mainly granite and quartz) are usually used as aggregates for the manufacture of concrete products and structures. This raw material is tested, reliable and does not cause destruction during operation of structures. However, it is exhaustive and characterized by high cost. That is why it is advisable to consider the use of reactive (active) aggregates. Especially if you consider ways to eliminate alkaline corrosion. The development of alkaline concrete compositions with the use of active aggregates is the key to expanding the raw material base for the manufacture of building materials with a reduction in production costs compared to products based on traditional systems. The use of active mineral additives allows to reduce the content of free alkalis in the system, preventing the alkaline corrosion of hardened artificial stone. Simultaneously. the processes of interaction of the active siliceous component with alkalis in the cement system can be transferred from the category of destructive (such as destroying the structure of hardened stone) in constructive processes (binding these components into insoluble compounds during hydration and cement formation, without breaking its fixed structure and sealing material). Studies have shown the high efficiency of the proposed approaches for the binding of excess alkalis (more than 0.6%) and targeted synthesis of alkaline aluminosilicate-type tumors in the composition of artificial cement stone. At the same time, the issue of extending the results to control the formation of structures at different levels of concrete with the use of general construction cements requires further research, and the issue of stopping alkaline corrosion of hardened concrete has not been raised and is innovative from the point of view of domestic and world science.
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31

Chen, Jiaqi, Lanchun Zhang, Yinfei Du, Hao Wang, and Hancheng Dan. "Three-dimensional microstructure based model for evaluating the coefficient of thermal expansion and contraction of asphalt concrete." Construction and Building Materials 284 (May 2021): 122764. http://dx.doi.org/10.1016/j.conbuildmat.2021.122764.

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32

Li, Ke, and Shao Fei Zhao. "Research on the Civil Engineering and Architecture Based on Thermodynamics." Applied Mechanics and Materials 380-384 (August 2013): 4862–67. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.4862.

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With the constant improvement of the national economic level, the requirements on the building security are also increasing. The external temperature is a major factor leading to unsafe buildings. It is very necessary to research the civil engineering and architecture under the thermodynamic environment. The concrete will crack with the change of the temperature. According to this, the paper studies the reason and defensive measures of expansion caused by heat and contraction caused by cold based on thermodynamic principles. According to climatic characteristics, this article proposes the preservation and heat insulation of buildings, protection the buildings from icy frost damage and the ventilation of the buildings through the selection of building materials. It solves the cracking problem of the concrete very good with the change of the temperature. The research of this paper provides some reference for other research on the civil construction.
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33

Ahmed, Ali, Shoaib Ameer, Safeer Abbas, Wasim Abbass, Afia Razzaq, Abdeliazim Mustafa Mohamed, and Abdullah Mohamed. "Effectiveness of Ternary Blend Incorporating Rice Husk Ash, Silica Fume, and Cement in Preparing ASR Resilient Concrete." Materials 15, no. 6 (March 14, 2022): 2125. http://dx.doi.org/10.3390/ma15062125.

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Although the disposal of waste ashes causes environmental hazards, recycling them helps in reducing their harmful impacts and improves the characteristics of building materials. The present study explores the possible use of locally available waste ashes including Rice husk ash (RHA)and Silica Fumes (SF) as a partial replacement for cement in concrete to counter the negative impact of alkali-silica reactions (ASRs). In the present study, ternary blends including RHA (0–30%), SF (5% and 10%) and Portland cement were investigated. The amorphous behavior of RHA and SF was confirmed by conducting an X-ray diffraction analysis. A petrography analysis was carried out to ensure the reactive nature of aggregates used to prepare the concrete specimen. Accelerated mortar bar tests were performed in accordance with ASTM C 1260 for up to 90 days. It was revealed that specimens incorporating a ternary blend of SF, RHA, and Portland cement exhibited less expansion compared to the control specimens without SF and RHA. The incorporation of 5% SF along with 20% RHA exhibited a 0.13% expansion at 28 days and 10% SF, along with 5% RHA which exhibited 0.18% expansion at 28 days which is within the range specified by ASTM C 1260, with the lowest compromise of the mechanical properties of concrete. Thus, the utilization of SF and RHA in the partial replacement of cement in concrete may be considered a practical approach to mitigate ASR effects as well as to reduce the environmental burden.
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34

Garcia Diosa, Jaime Andres, Alejandro Gonzalez Orive, Guido Grundmeier, Ruben Jesus Camargo Amado, and Adrian Keller. "Morphological Dynamics of Leukemia Cells on TiO2 Nanoparticle Coatings Studied by AFM." Applied Sciences 11, no. 21 (October 22, 2021): 9898. http://dx.doi.org/10.3390/app11219898.

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Coatings of modified TiO2 nanoparticles (TiO2-m) have been shown to effectively and selectively trap non-adherent cancer cells, with an enormous potential for applications in photodynamic therapy (PDT). Leukemia cells have a remarkable affinity for TiO2-m coatings, adhering to the surface by membrane structures and exhibiting morphologic characteristics of amoeboid locomotion. However, the details of the cell–substrate interaction induced by the TiO2-m coating remain elusive. With the aim to obtain a better understanding of this phenomenon, leukemia cell adhesion to such coatings was characterized by atomic force microscopy (AFM) for short contact times up to 60 min. The cell and membrane morphological parameters mean cell height, contact area, cell volume, and membrane roughness were determined at different contact times. These results reveal cell expansion and contraction phases occurring during the initial stage of adhesion. Subsequently, the leukemic cells reach what appears to be a new resting state, characterized by pinning of the cell membrane by TiO2-m nanoparticle aggregates protruding from the coating surface.
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35

Yan, Kai, Yansong Hu, Kaozhong Zhao, and Xin Lin. "Study on Safety Performance of Building Finish Layer under Thermomechanical Coupling Condition." Advances in Materials Science and Engineering 2021 (September 20, 2021): 1–16. http://dx.doi.org/10.1155/2021/3438613.

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The building finish layer is a comprehensive structural system including the building exterior insulation system and building exterior finish. Combining with buildings has the advantage of reducing wall heat loss and building deformation caused by large temperature differences. Since the building finish layer is prone to cracking, hollowing, and peeling, during the application process, its safety needs to be studied and certified. This study prepares 20 groups of specimens, 15 anchor bolts in each group. The anchor bolt pull-out strength test is carried out. Anchoring damage evolution law and failure mode of anchor bolts are investigated. And the influence of anchoring methods on the pull-out bearing capacity is analyzed. In addition, ABAQUS finite element data simulation is carried out. The stress state of finish in thermomechanical coupling condition and without the effect of temperature are compared and analyzed. The influence factors of anchor bolt pull-out strength and the influence of temperature load on the long-term performance of building finish layer are obtained. The durability of the building finish layer is analyzed. The results show that the anchoring strength of the anchor bolt is positively correlated with the anchoring depth. The anchoring strength is influenced significantly by anchoring construction sequence and temperature. The stress under the coupled effect of temperature and load is greater than that of the single effect of load, and the stress distribution changes significantly. Due to thermal expansion and contraction, the anchor bolt would loosen, which is more prone to damage the building finish layer in a low temperature environment. The weight relationship of each influencing factor of the building finish layer is proposed. A systematic evaluation index system is established. The results of this study provide a basis for subsequent related research work and engineering applications.
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36

Miura, Taito, Stéphane Multon, and Yuichiro Kawabata. "Influence of the distribution of expansive sites in aggregates on microscopic damage caused by alkali-silica reaction: Insights into the mechanical origin of expansion." Cement and Concrete Research 142 (April 2021): 106355. http://dx.doi.org/10.1016/j.cemconres.2021.106355.

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37

Abalouch, Ibtissam, Siham Sakami, Fatima-Ezzahra Elabbassi, and Lahcen Boukhattem. "Effects of Recycled Fine Glass Aggregates on Alkali Silica Reaction and Thermo-Mechanical Behavior of Modified Concrete." Applied Sciences 11, no. 19 (September 28, 2021): 9045. http://dx.doi.org/10.3390/app11199045.

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The objective of this work is to develop a new composite material by substituting sand with recycled waste glass (RWG). Different volume percentages of RWG varying from 0 to 50% were incorporated into concrete, with maximum size that did not exceed 1.25 mm. The microscopic characterization by scanning electron microscopy SEM-EDS and optical microscopic test, as well as the durability against alkali silica reaction (ASR) test, were performed respectively to visualize the morphology and assess the damage caused by ASR. Furthermore, the mechanical and thermophysical properties measurements were carried out. The results of microscopic characterization showed the presence of cracks inside a minority of glass particles due to ASR, and ASR test indicated that expansion activity remained well below the limit expansion value of 0.15%. The obtained results also showed that, at 28 and 90 days of curing, compressive strength increased respectively by up to 1.63% and 29% for 20% of the incorporated RWG volume rate in concrete; however, beyond this rate it diminished receptively by 30% and 3.2%. This improvement with curing age was attributed to pozzolanic reaction. Regarding density, it reduced by around 5%. Furthermore, thermal conductivity and thermal effusivity decreased respectively by 36% and 8.06% at dry state and they dropped respectively by 44% and 21.28% at saturated state, related to reference concrete RC. It is therefore feasible to substitute high amount of natural sand with RWG to obtain new composite that may be successfully used as structural material in construction building.
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Chen, Jun, Cheng Yao, Hao Wang, Yangmin Ding, and Tao Xu. "Expansion and contraction of clogged open graded friction course exposed to freeze-thaw cycles and degradation of mechanical performance." Construction and Building Materials 182 (September 2018): 167–77. http://dx.doi.org/10.1016/j.conbuildmat.2018.06.095.

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39

Lu, Duyou, Laibao Mei, Zhongzi Xu, Mingshu Tang, Xiangyin Mo, and Benoit Fournier. "Alteration of alkali reactive aggregates autoclaved in different alkali solutions and application to alkali-aggregate reaction in concrete (II) expansion and microstructure of concrete microbar." Cement and Concrete Research 36, no. 6 (June 2006): 1191–200. http://dx.doi.org/10.1016/j.cemconres.2006.01.012.

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40

Kantautas, Aras, and Giedrius Vaickelionis. "MODIFIED SAWDUST CONCRETE/MODIFIKUOTAS PJUVENŲ BETONAS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 6, no. 2 (April 30, 2000): 113–19. http://dx.doi.org/10.3846/13921525.2000.10531574.

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Wood-cement materials are widely produced and applied in many developed countries. In this case special prepared wood aggregates are employed. Wood sawdust practically is not employed. Extracts, present in wood, slow down the cement hydration. The influence of mineral additives on this process was determined. The efficiency of mineral additives depends on their hydraulic activity. It has been found that the mineral components (additives) of sawdust concrete have a positive effect on cement setting and hardening due to two reasons: 1) hydraulic and other mineral additives absorb wood extracts from liquid phase which inhibit and retard setting of cement and reduce their concentration in solution; 2) reduce pH of liquid phase so the hemicellulose which is in sawdust or other wood aggregates, less disintegrate lightly soluable sugars. When sawdust amounts are different, the optimum cement and rottenstone relation is not constant: y = 1,29x −0,66 where y is cement and rottenstone mass relation, x is sawdust and binding material (cement+rottenstone) volume relation. The influence of sawdust concrete humidity on its strength was found: where y is concrete compressive strength (MPa), when its humidity X (%), R is concrete compressive strength (MPa), when its humidity W(%). The possibility of accelerating the hardening process of concrete mixes of cement-rottenstone (gaize)-sawdust system by means of steaming at 80 °C was studied, too. It is impossible when producing ordinary wood-cement materials. The physical and technical properties of sawdust concrete such as shrinkage strain, expansion deformations and elastic modulus were determined. Sawdust concrete contraction deformation depending on concrete density may vary by 8…14 mm/m and expansion (in humid conditions) by 1,1…2,5 mm/m. Deformation decreases when quartz sand additive is used. When the concrete gets dry repeatedly, deformations are smaller. The sawdust concrete elasticity modulus is similar to that of light concrete with inorganic additives having the same density. Its frost resistance depends on the concrete structure and cement quantity. When the concrete with a small amount of sawdust is used (cement+additive: sawdust=5:1), the samples endure 75 freezing cycles. The heat conductivity of sawdust concrete is low. The experimental data have shown that structural thermoinsulated small blocks can be produced from these concrete mixes.
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41

Wei, Yi. "Feasibility of the Development of New PVC/Fine Sand Imitation Stone Composite Materials to Promote Rural Urbanization." Journal of Nanomaterials 2022 (June 16, 2022): 1–13. http://dx.doi.org/10.1155/2022/2682278.

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At present, with the acceleration of rural urbanization, people’s market demand for new building materials is also increasing, and the research and development of new PVC/fine sand imitation stone composite materials are also in continuous progress and development. The purpose of this article is to analyze the feasibility of developing new PVC/fine sand imitation stone composite materials to promote rural urbanization and propose the application of more new PVC/fine sand imitation stone composite materials to our urbanization construction. In, we first conducted research on the new PVC/fine sand imitation stone composite material and rural urbanization, and then, we conducted research on the various properties of the new PVC/fine sand imitation stone composite material and the development of rural urbanization. The research results show that the new PVC/fine sand imitation stone composite material has at least 400% improvement in compressive performance compared with the traditional PVC material, and it is also better than the traditional PVC material in terms of the material expansion and contraction performance, which is more conducive to the application our rural urbanization is under construction.
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42

Kovalchuk, Oleksandr, and Viktoriia Zozulynets. "Development of alkaline concrete on the basis of active aggregates." Technology audit and production reserves 6, no. 1(62) (December 8, 2021): 36–42. http://dx.doi.org/10.15587/2706-5448.2021.244780.

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The object of the research is the process of directed structure formation in the body of alkaline concrete, made using a reactive aggregate, in this case, basalt, and the process of deformation development in such concrete. The problem with using reactive aggregates is that they cause alkaline corrosion. It manifests itself in the form of cracks and layers of gel-like substances that form at the point of contact of the aggregate with the cement stone. During the research, methods of physical and chemical analysis were used (X-ray phase, differential thermal and thermogravimetric analyzes, electron microscopy, infrared spectroscopy, microprobe analysis). And also methods of mathematical planning of experiments have been used for the dependence of the physical and technical properties of cements and the directions of their structure formation. Also, the research has been carried out based on the analysis of world achievements in solving the problem of alkaline corrosion of concrete. The possibility of joint operation of the matrix of alkaline cements and active aggregates, represented by basalt, has been determined. The component composition of alkaline cement has been optimized and the need to increase the amount of the alkaline component in the system for the normal course of structure formation processes has been proved. The study of the influence of technical factors and conditions of hardening on the development of processes of structure formation of the investigated compositions has been carried out. The deformation properties of fine-grained concrete based on slag-alkaline cement and basalt aggregate have been investigated. It is shown that the expansion deformations of the samples, which accompany the process of alkaline corrosion of the aggregate in concrete, are directly related to the component composition and hardening conditions of the material. The obtained research results confirm the possibility of using active aggregates for the manufacture of building materials, in particular, based on alkaline cements. But for the safe course of the processes of structure formation, the component composition of the system has to be adjusted by introducing an active mineral additive and an additional alkaline component. The use of hydrophobizing additives makes it possible to increase the strength of the material even when operating under normal heat and humidity conditions.
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43

Fournier, B., and M. A. Bérubé. "Application of the NBRI accelerated mortar bar test to siliceous carbonate aggregates produced in the St. Lawrence Lowlands (Quebec, Canada) part 2: Proposed limits, rates of expansion, and microstructure of reaction products." Cement and Concrete Research 21, no. 6 (November 1991): 1069–82. http://dx.doi.org/10.1016/0008-8846(91)90067-r.

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44

Miah, Md Jihad, Md Munir Hossain Patoary, Suvash Chandra Paul, Adewumi John Babafemi, and Biranchi Panda. "Enhancement of Mechanical Properties and Porosity of Concrete Using Steel Slag Coarse Aggregate." Materials 13, no. 12 (June 26, 2020): 2865. http://dx.doi.org/10.3390/ma13122865.

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This paper investigates the possibility of utilizing steel slags produced in the steelmaking industry as an alternative to burnt clay brick aggregate (BA) in concrete. Within this context, physical, mechanical (i.e., compressive and splitting tensile strength), length change, and durability (porosity) tests were conducted on concrete made with nine different percentage replacements (0%, 10%, 20%, 30%, 40%, 50%, 60%, 80%, and 100% by volume of BA) of BA by induction of furnace steel slag aggregate (SSA). In addition, the chemical composition of aggregate through X-ray fluorescence (XRF) analysis and microstructural analysis through scanning electron microscopy (SEM) of aggregates and concrete were performed. The experimental results show that the physical and mechanical properties of concrete made with SSA were significantly higher than that of concrete made with BA. The compressive and tensile strength increased by 73% when SSA fully replaced BA. The expansion of concrete made with SSA was a bit higher than the concrete made with BA. Furthermore, a significant lower porosity was observed for concrete made with SSA than BA, which decreased by 40% for 100% SSA concrete than 100% BA concrete. The relation between compressive and tensile strength with the porosity of concrete mixes are in agreement with the relationships presented in the literature. This study demonstrates that SSA can be used as a full replacement of BA, which is economical, conserves the natural aggregate, and is sustainable building material since burning brick produces a lot of CO2.
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45

Choudhary, Rajan, Dibyatonu Chattopadhyay, Abhinay Kumar, and Ashok Julaganti. "Use of industrial wastes as filler in open-graded friction courses." Baltic Journal of Road and Bridge Engineering 12, no. 2 (June 27, 2017): 106–16. http://dx.doi.org/10.3846/bjrbe.2017.13.

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For a fast developing economy like India, expansion, rehabilitation, and maintenance of transportation infrastructure is crucial and require huge quantities of high quality natural aggregates. Meanwhile, vast amounts of industrial wastes accumulating in the country pose problems related to safe and sustainable disposal. The present study investigated possible utilisation of marble dust, a waste from stone industry, and fly ash, a waste from thermal power stations, as filler materials in open-graded friction course mixes. Open-graded friction course mixes incorporating fly ash, marble dust, and two sources of stone dust as filler fractions were designed and evaluated for mix design properties including draindown, abrasion loss, air void content, and permeability. Morphology of each filler was characterised through scanning electron microscopy. Physicochemical properties of fillers were examined through Rigden voids, German filler test, methylene blue, and hydrometer analysis. Analysis of variance using Fisher multiple comparison procedure was performed to evaluate the effect of filler type on design properties of open-graded friction course mixes. Regression analysis using forward selection technique was performed to identify significant filler characteristics influencing open-graded friction course properties. Results showed that filler type affected open-graded friction course design parameters significantly. Open-graded friction course mixes with marble dust showed promising performance with lowest draindown, and highest durability, air voids, and permeability. Regression analysis identified Rigden void content of filler materials as a major filler characteristic affecting the mix design parameters of open-graded friction course mixes.
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46

Perez Castellanos, Nora, and Lauro Bucio Galindo. "Influence of Crystalline and Amorphous Phases on pre-Hispanic Adobes Properties." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1312. http://dx.doi.org/10.1107/s2053273314086872.

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Adobe earth bricks are part of the past and present in Mexican culture, they have shown to have the right mechanical strength and time resistance that is adequate for a good constructive system. Adobe bricks are built from natural soil, which is an abundant and therefore potentially sustainable material. The archaeological site of Cholula, Puebla, Mexico is one of the most important pre-Hispanic cities during 300-900 A.D. The pyramid at the site has the largest volume and basing in the world and plays a very important role in the community since pre-Hispanic times up until now when it is a symbol of religious syncretism. This research seeks to provide a comprehensive study of the type of adobe earth bricks that were used as building material. The crystallographic study of this type of cultural heritage materials enables the expansion of our knowledge about the details concerning the structure and properties. This was achieved by identifying the role that each mineral plays on the properties of the adobe by integrating knowledge from mineralogy with that of materials science. The relationship between structure and function was foundational to understanding materials and from this knowledge it is possible to develop pathways on how to control and forecast the properties of earth building materials [1]. The results obtained from the XRD analysis of the different granulometric phases showed that plagioclase and quartz constitute the larger aggregates forming the sand phase, whilst a mixture between cristobalite and tridymite, constituted the mineral opal CT, which together with amphibole minerals formed the silt phase, the clay sized particles corresponded to amorphous phases such as allophane, glass and organic material [2, 3]. We concluded that the combination of these minerals in both cohesive and non-cohesive phases that are present in the regional soils fulfill the requirements for building ancient cities and still remain functional up until today.
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47

Spathis, Panayotis K., Maria Mavrommati, Eirini Gkrava, Vasilios Tsiridis, Sotiris P. Evgenidis, Ioannis Karapanagiotis, Vasilios Melfos, and Thodoris D. Karapantsios. "Characterization of Natural Stone from the Archaeological Site of Pella, Macedonia, Northern Greece." Heritage 4, no. 4 (December 15, 2021): 4665–77. http://dx.doi.org/10.3390/heritage4040257.

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The goal of the study was to characterize the limestone that was used extensively in the ancient city of Pella (Macedonia, Greece), the birthplace of Alexander the Great. An on-site examination of the building material was carried out to record the types of damage and to select sampling areas. A variation in the nature of the stone and the degree of deterioration, even between the stones that comprise a specific monument structure, was observed, with water absorption and biological colonization being the main factors resulting in the deterioration of the stone. A comprehensive microanalysis and testing scheme was conducted to fully characterize the mineralogical, chemical, mechanical and thermal properties of the stones collected from various areas of the archaeological site. Optical microscopy, XRD and SEM–EDX were used to investigate the chemical composition and the structure of the stone samples. Finally, other properties, such as porosity, specific gravity and water absorption, were measured. Surface alterations, material degradation and biological deterioration were observed in most samples. The results obtained using XRD showed that the dominant mineral phase of the limestone is calcite, with quartz and clay minerals also detected in traces. The microscopic examination of the samples showed that the main natural stone at the archaeological site is a marly limestone. Thermographical measurements showed that the decay of the stones due to ambient temperature variation and corresponding contraction/expansion phenomena may be relatively limited, as the stone exhibited a low thermal diffusivity. Moreover, high porosity values (12.06–21.09%) and low compressive strength (11.3–27.7 MPa) were recorded, indicating the vulnerability of the stone and the need to take conservation measures.
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48

Gómez, A., J. Rodríguez-Hernández, and E. Reguera. "Crystal structures of cubic nitroprussides: M[Fe(CN)5NO]·xH2O(M=Fe, Co, Ni). Obtaining structural information from the background." Powder Diffraction 22, no. 1 (March 2007): 27–34. http://dx.doi.org/10.1154/1.2700265.

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A new structural model is proposed for cubic nitroprussides and the crystal structure for the complex salts of Fe(2+), Co(2+), and Ni(2+) refined in that model. In cubic nitroprussides the building unit, [Fe(CN)5NO]2−, and the assembling metal (M=Fe2+, Co2+, Ni2+), have ¾ occupancy with three formula units per cell (Z=3). This leads to certain structural disorder and to different local environments for the outer metal. The crystallographic results are supported by the Mössbauer and infrared data. The XRD powder patterns, index in a cubic cell (Fm3m space group), show a sinuous background because of diffuse scattering from positional disorder of the metal centers. Because of this, the crystal structures were refined allowing the metal centers to move from the (0,0,0) and (0,0,1/2) positions (away from positional symmetry restrictions). The refinement under these conditions leads to excellent agreement factors (Rwp, Rp, S), good pattern background fitting, and produced a refined structural model consistent with the crystal chemistry of nitroprussides. The studied materials are obtained as hydrates. On heating, the crystal water evolves, and below 100°C an anhydrous phase is obtained, preserving the framework of the original hydrates. The loss of the crystal water leads to cell contraction that represents around 2% of cell volume reduction. On cooling down from room temperature to 77 and 12 K, a slight expansion for the -M-N≡C-Fe-C≡N-M- chain length is observed, suggesting that at low temperature and reduction in the metals charge delocalization on the CN bridges takes place. For M=Fe and Co the crystal structure was also refined for the anhydrous phase at 12, 77, and 300 K.
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Colman, Charlotte, David Bulteel, Bouarroudj Mohamed Elkarim, Sébastien Rémond, and Luc Courard. "Expansion of concrete by secondary ettringite formation, caused by fine recycled aggregates contaminated with gypsum." Advances in Cement Research, December 19, 2022, 1–25. http://dx.doi.org/10.1680/jadcr.22.00043.

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Recycled aggregates, and especially the fine (0/4 mm) fraction, are often contaminated with sulfates coming from gypsum residues on the demolition site. When these aggregates are used in concrete, the sulfates can induce internal sulfate attack which causes the expansion of concrete. Standard EN206 sets the water soluble sulfate limit at 0.2 % by weight of the aggregate but other studies suggest this limit could be safely increased. In addition to the sulfate content, other parameters like the porosity and alkalinity of a mix have been seen to influence the swelling results. In this study, the different proposed sulfate limits are evaluated on concrete made with 100 % fine recycled aggregates. It is also researched whether mixing parameters could change the swelling amount regardless of sulfate content. The results showed that the incorporation of fine recycled aggregates with sulfate contents up to 0.8 mass% is safe when combined with coarse natural aggregates. If coarse recycled aggregates are used, the sulfate content of fine recycled aggregates could reach up to 0.3 %. The swelling caused by these sulfate levels was not high enough to be influenced by porosity or alkalinity.
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50

Winnefeld, Frank, Gregor J. G. Gluth, Susan A. Bernal, Maria C. Bignozzi, Lorenza Carabba, Sundararaman Chithiraputhiran, Alireza Dehghan, et al. "RILEM TC 247-DTA round robin test: sulfate resistance, alkali-silica reaction and freeze–thaw resistance of alkali-activated concretes." Materials and Structures 53, no. 6 (November 11, 2020). http://dx.doi.org/10.1617/s11527-020-01562-0.

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AbstractThe RILEM technical committee TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ conducted a round robin testing programme to determine the validity of various durability testing methods, originally developed for Portland cement based-concretes, for the assessment of the durability of alkali-activated concretes. The outcomes of the round robin tests evaluating sulfate resistance, alkali-silica reaction (ASR) and freeze–thaw resistance are presented in this contribution. Five different alkali-activated concretes, based on ground granulated blast furnace slag, fly ash, or metakaolin were investigated. The extent of sulfate damage to concretes based on slag or fly ash seems to be limited when exposed to an Na2SO4 solution. The mixture based on metakaolin showed an excessive, very early expansion, followed by a dimensionally stable period, which cannot be explained at present. In the slag-based concretes, MgSO4 caused more expansion and visual damage than Na2SO4; however, the expansion limits defined in the respective standards were not exceeded. Both the ASTM C1293 and RILEM AAR-3.1 test methods for the determination of ASR expansion appear to give essentially reliable identification of expansion caused by highly reactive aggregates. Alkali-activated materials in combination with an unreactive or potentially expansive aggregate were in no case seen to cause larger expansions; only the aggregates of known very high reactivity were seen to be problematic. The results of freeze–thaw testing (with/without deicing salts) of alkali-activated concretes suggest an important influence of the curing conditions and experimental conditions on the test outcomes, which need to be understood before the tests can be reliably applied and interpreted.
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