2012-5-30 properties than natural aggregate for the workability of fresh concrete. Crushed rock grains are usually flakier, elongated and rough. In addition to that, crushed rocks normally have more fine particles. With crushed granite rocks large amounts of flaky free mica in the fine fractions is common and leads to problems with workability. The main ...
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Concrete in Sweden has traditionally been manufactured with natural aggregate from glaciofluvial eskers. There is a need to preserve the remaining eskers because of their cultural value and importance for water filtration, thus natural aggregate has to be replaced. The most realistic alternative is to use crushed rocks.
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The major problem with crushed rocks in concrete production is the workability. This is because crushed rocks have less favorable properties. The fragments are flakier and have a rougher surface than natural aggregates that have been rounded in water. Without any amelioration of the crushed rock, to reach a certain workability and strength, the ...
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2021-1-1 The use of crushed limestone dust may affect the properties of concrete. As per Celik and Marar the inherent property of concrete to flow known as workability decreases with the use of crushed limestone dust. This is due to the presence of finer particles whose specific surface area is high, which absorbs more water and leads to a reduction in slump value.
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In general terms this study has confirmed that water-cement ratio has the most notable impact on the properties (such as workability and strength) of mortars and concrete. Considering the geological aspects the mortar properties were more sensitive to mineral aggregates than to the fine crushed rocks formed from these minerals.
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1996-7-1 If there is a reluctance to use crushed rock aggregates in concrete manufacturing, it is primarily based on this allowance of a higher dust content in crushed rock fines than that in the natural sand. Most of the crushed rock fine aggregate produced in N. Cyprus contains approximately 17 - 25% of dust.
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2019-1-1 Particle size distribution curves of recycled aggregates from concrete pavement crushed by jaw and impact crushers. The jaw crusher produced 85% coarse aggregates (fraction >4.8 mm), whereas the impact crusher produced 82% coarse aggregates. In both cases, the content of particles finer than 0.15 mm was less than 2% mass.
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2017-6-1 The quality and durability of concrete depends on compressive strength, which is described as the ability to resist the destructive internal strains caused by external compressive loads. 100 × 100 × 100 mm cubes were used to evaluate this property according to the methodology described in the Standard EN 12390-3.The density of concrete was measured
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Millions of stones of crushed rock are needed annually for road base, paving, ready-mixed concrete and asphalt. The study of the properties of stones is a part of
MoreConcrete in Sweden has traditionally been manufactured with natural aggregate from glaciofluvial eskers. There is a need to preserve the remaining eskers because of their cultural value and importance for water filtration, thus natural aggregate has to be replaced. The most realistic alternative is to use crushed rocks.
More
2019-2-15 Aggregate impact value gives a relative measure of the resistance of an aggregate to sudden shock or impact, As an alternative to crushing value, the aggregate impact value should not exceed 45% by weight for aggregates used for concrete other than for wearing surfaces and 30% by weight for concrete for wearing surfaces, such as runways, roads ...
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2018-1-2 grade of cement is used for concrete. The properties of cement were determined as per the IS 8112:1989 and results are given in the table 1. Table -1: Properties of cement Properties Values Compressive strength 43 Mpa Fineness 5% Initial setting time 30 minutes Final setting time 10 hour Specific gravity 3.15
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2015-1-13 Aggregates generally occupy 65- 80% of a concrete’s volume. Aggregates are inert fillers floating in the cement paste matrix for concretes of low strength. The strength of aggregates do not contribute to the strength of concrete for low strength concrete. The characteristics of aggregates impact performance of fresh and hardened concrete.
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2018-8-31 The material model should encapsulate rock’s brittle behaviour and also model large-strain impact upon loading. A few “concrete” models have widely been accepted to investigate the rock performance under large strain loading because of similarity between asphaltic concrete and rock in compression (Malvar et al. 1997).Others including Ramulu et al. have shown that the
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maximum tensile strength of concrete is obtain at 60% and 70% replacement of natural sand with Crushed sand. The concrete with crushed sand performed better than concrete with natural sand as the property of crush sand is better than that of natural sand. Keywords: Natural Sand, Crushed Sand, Concrete, Compressive Strength and Tensile Strength 1.
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2013-3-29 This paper discusses the properties of RCA, the effects of RCA use on concrete material properties, and the large scale impact of RCA on structural members. The review study yielded the following findings in regards to concrete material properties: (1) replacing NA in concrete with RCA decreases the compressive strength, but yields comparable splitting tensile
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Los Angeles (LA) Abrasion is a widely-used procedure that has been around for many years and produces values that are well understood.Dry coarse aggregate samples are rotated in a large steel drum with an abrasive charge of steel balls.
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California bearing ratio (CBR) test was carried out, CBR changing laws of different graded crushed rocks were analyzed, an aggregate gradation on the base of port was put forward, and its performances were verified through laboratory test. Test result shows that the main skeleton structure composed of the aggregate with diameter 19mm-4.75 mm has interlocked force, and
MoreMillions of stones of crushed rock are needed annually for road base, paving, ready-mixed concrete and asphalt. The study of the properties of stones is a part of
More2012-5-30 properties than natural aggregate for the workability of fresh concrete. Crushed rock grains are usually flakier, elongated and rough. In addition to that, crushed rocks normally have more fine particles. With crushed granite rocks large amounts of flaky free mica in the fine fractions is common and leads to problems with workability. The main ...
MoreConcrete in Sweden has traditionally been manufactured with natural aggregate from glaciofluvial eskers. There is a need to preserve the remaining eskers because of their cultural value and importance for water filtration, thus natural aggregate has to be replaced. The most realistic alternative is to use crushed rocks.
More
2020-1-12 The Concrete has been traditionally made with use of Natural / River sand as fine aggregate. As sand contributes to around 25 to 35% of total concrete along with coarse aggregates, cement water, the properties of the fine aggregates would be one of the major influencing factor in determining the fresh hardened Concrete Read More »Use of
Moremaximum tensile strength of concrete is obtain at 60% and 70% replacement of natural sand with Crushed sand. The concrete with crushed sand performed better than concrete with natural sand as the property of crush sand is better than that of natural sand. Keywords: Natural Sand, Crushed Sand, Concrete, Compressive Strength and Tensile Strength 1.
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In this study, crumb rubber with particle sizes ranging from 400 to 600 μm (fine) to 10-15 mm (coarse), 20 mm recycled crushed concrete (RCC), and 20 mm crushed rock (CR) were used. The crumb rubber was added to the two groups of CD aggregates at 0.5, 1 and 2% by weight percentages of the aggregates.
More2018-8-31 The material model should encapsulate rock’s brittle behaviour and also model large-strain impact upon loading. A few “concrete” models have widely been accepted to investigate the rock performance under large strain loading because of similarity between asphaltic concrete and rock in compression (Malvar et al. 1997).Others including Ramulu et al. have shown that the
MoreLos Angeles (LA) Abrasion is a widely-used procedure that has been around for many years and produces values that are well understood.Dry coarse aggregate samples are rotated in a large steel drum with an abrasive charge of steel balls.
More2013-3-29 This paper discusses the properties of RCA, the effects of RCA use on concrete material properties, and the large scale impact of RCA on structural members. The review study yielded the following findings in regards to concrete material properties: (1) replacing NA in concrete with RCA decreases the compressive strength, but yields comparable splitting tensile
More
2019-8-24 rocks from the earth crust. A wide variety of products from quarries form primary raw materials in many industrial applications. Crushed rocks are used as aggregate in highways or concrete and in bitumen plants and rail track construction. Quarry operations are carried out by diverse surface methods such as hard rock
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2022-1-11 Fineness Modulus has larger impact on 28 days Compressive Flexural Strength. Fineness Modulus has very little impact on Permeability of Concrete. Permeability coefficientis changed by about 2% for FM from 2.0 to 3.0. Fineness Modulus also affects the density of concrete. It increases by about 2.3% as the FM increases from 2.0 to 3.0.
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