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2023年10月3日 Concrete, in construction, structural material consisting of a hard, chemically inert particulate substance, known as aggregate
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Aggregates comprise as much as 60% to 80% of a typical concrete mix, so they must be properly selected to be durable, blended for optimum
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2017年8月5日 Hydraulic cement concrete is a cement and water paste in which aggregate particles are embedded. Aggregate is granular material such as sand, gravel, crushed
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179 Reads P. E. Grattan-Bellew G. Cybanski B. Fournier L. D. Mitchell The Concrete Microbar Test is modified after a Chinese test, for alkali-carbonate reactive aggregates.
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2021年4月20日 The scanning area is divided into cement matrix, aggregate surface and aggregate cement interface to evaluate the effect of different agitation methods on cement particle distribution and gel
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2022年3月1日 open access Abstract Several industrial by-products are extensively used again as a supplementary cementitious material or aggregates in the interest to reduce
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China's demand for Cement, Concrete Aggregate will continue to grow at about 8% by 2032. China's demand for Cement, Concrete Aggregate has grown at a fast pace in
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The total water/cement ratio does not take into account the absorption ability of the recycled aggregate, while the effective water/cement ratio does and allows for only the water
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Recycled aggregate concrete (RAC) is made by crushing, cleaning, and classifying discarded concrete blocks and mixing part or all of them with a specific gradation with
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Cement Aggregate Water Air Range7% - 15% 60% - 80% 14% - 18% 2% - 8%: Quality Counts. Make sure that your concrete producer purchases good-quality aggregate as verified by regular aggregate test results in
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2023年3月23日 Standard specification for lightweight aggregate for internal curing of concrete. ASTM C1761-17. West Conshohocken, PA: ASTM. Google Scholar. ... Husem, M. 2003. “The effects of bond strengths between lightweight and ordinary aggregate-mortar, aggregate-cement paste on the mechanical properties of concrete.” Mater. Sci. Eng., A
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2022年10月3日 Aggregate-cement paste interface: Part I. Influence of aggregate geochemistry Cement and Concrete Research , 29 ( 7 ) ( 1999 ) , pp. 1019 - 1025 , 10.1016/S0008-8846(99)00086-1 View PDF View article View in Scopus Google Scholar
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2021年11月22日 Therefore, considering recent annual production of cement worldwide (4–4.2 Gt), about half of aggregates (from the total of 40–50 Gt) is spent in the manufacturing of hydraulic cement concrete (similar estimates can be found elsewhere—see e.g., Gagg 2014). Another 2 Gt of aggregates are bound by bitumens in asphaltic
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1999年7月1日 In order to study the influence of aggregate chemistry on the microstructure of the ITZ, test specimens were prepared for SEM-energy dispersive X-ray analyser (EDAX) analysis as shown schematically in Fig. 1.The aggregates were sawed up into 20 × 40 × 5 mm slices and a layer (approximately 5 mm thick) of cement paste [water/cement ratio
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2021年11月2日 Also marble waste aggregate has higher carbonate content than the natural aggregate, which improves the aggregate cement paste bond that is the reason for the increase in split tensile strength of ...
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2005年4月1日 The influence of the cement paste–aggregate interfacial transition zone (ITZ) on the frost durability of high-performance silica fume concrete (HPSFC) has been studied. Investigation was carried out on eight non-air-entrained concretes having water-to-binder (W/B) ratios of 0.3, 0.35 and 0.42 and different additions of condensed silica fume.
خبير الاتصال2021年5月1日 Aggregates make up between 60% and 80% of the volume of concrete, being surrounded by the cement paste. Aggregates are considered to be the most important factor affecting concrete strength. Moreover, aggregates increase the length of the fluid flow through the concrete microstructure and disconnect the connections of the pores in the
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2022年6月1日 The target porosity of specimens was set at 12%. The mixture ratio conforms to the requirements of the Technical Specification for Pervious Cement Concrete Pavement [33], which was calculated by the filling theory and the volume method [34].According to Lian and Zhuge [35], to ensure better strength and permeability,
خبير الاتصال2020年3月1日 But micro-cracks, which usually exist at the aggregate-cement interface, are much harder to control. The objective of this study is, therefore, to understand the micro-mechanisms that drive fracture propagation in concrete and assess the influence of aggregates on concrete strength. We take the example of the concrete used by the
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2023年3月3日 The use of alternative materials and recycling in construction has gained popularity in recent years as part of the industry#x2019;s commitment to sustainability. One such material,
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Rough-textured, angular, and elongated particles require more water to produce workable concrete than smooth, rounded compact aggregate. Consequently, the cement content must also be increased to maintain the water-cement ratio. Generally, flat and elongated particles are avoided or are limited to about 15 percent by weight of the total aggregate.
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2013年3月19日 There is a decrease in adhesive strength of the mortars without concrete fines when the cement-aggregate ratio decreases from 1:4 to 1:5. This is in agreement with the study of Carasek and Djanikian [ 23] who concluded that as the cement content increases the adhesive strength also increases. The mix with a 1:5 ratio and 15 %
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2023年7月20日 2.1. Test details. The test includes three parts: in the first part, the physical properties of coarse aggregate are taken as the research object, the effective water absorption, apparent density and crushing index of coarse aggregate are taken as variables; in the second part, the compressive strength of cement mortar is taken as the research
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2014年10月15日 Un-hydrated cement grains, natural aggregate: ⩾50 GPa. For the natural aggregate–paste interaction, according to Mehta’s concept [9] and other authors [7], [10], the ITZ is the one inside the cement paste and close to the aggregate which will be weaker than the rest of the paste. This weakness is due to the higher porosity.
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2021年11月1日 A coarse aggregate replacement scheme in concrete is investigated with three different waste ceramic tile materials in replacement ratios including 20%, 25%, 35%, 50%, 65%, 75%, 80% and 100%. Results show waste ceramic as a possible practicable natural coarse aggregate replacement material with minimal changes in mechanical
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2019年7月1日 Coral aggregate morphological features are described by three different levels of features [25, 37]: shape, angularity, and surface texture (See Fig. 2).The shape of the coral aggregate particles is characterized by the sphericity (ψ) [38], which reflects the spherical degree of the coral aggregate particles.The calculation equation is shown
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1998年7月1日 The aggregate-cement paste interfacial transition zone (ITZ) is known to be the weakest region in concrete, influencing both mechanical properties and durability performance. Many investigations 1, 2, 3 have shown that the amount and nature of the hydration products at the ITZ influence these properties of concrete. The processes
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2018年6月17日 Abstract. The microstructural characterization of concrete prepared with RCA is described in this chapter. The interfacial transition zone (ITZ) between the aggregate and the cement mortar matrix is the most important interface in concrete. Particularly, this is very important in RAC, as the recycled aggregate concrete has more interfaces than ...
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2017年6月1日 This region is important enough to consider the concrete microstructure as a composite made of three constituents: cement paste, ITZ and aggregate [10]. The cement paste volume should be considered as a factor in HPC shrinkage and durability [11]. Although shrinkage strains in HPC are similar to those of ordinary concretes, the process
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