High strength concrete is a useful material for high-rise buildings, long-span bridges, heavy-duty industrial floors, pre-stressed concrete, etc. Concrete is a mixture of cement, water, coarse and fine aggregates with or without chemical and mineral admixtures. As aggregate covers 75 percent of the volume of concrete, for HSC, high-strength ...

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Therefore, for high strength concrete the water/cement ratio is limited to less than 0.4 and the strength at the interface of cement and aggregate is similar to the crushing strength of coarse aggregates. Although the improvement in strength leads to increases …

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Gravel, cobble and boulders come under this category. The maximum size aggregate used may be dependent upon some conditions. In general, 40mm size aggregate used for normal strengths, and 20mm size is used for high strength concrete. the size range of …

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The paper describes a research to evaluate the performance of nickel slag-aggregate high strength concrete (NSA-HSC). Nickel slag, as a by-product from nickel mines, was used as aggregates, either as coarse aggregates or both fine and coarse aggregates, to produce high strength concrete.

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It has been shown that high strength lightweight aggregate concrete (HSLWAC) has a compressive strength of typically between 34 and 69 MPa through the incorporation of various pozzolans and water reducers. HSLWAC has a water to cement ratio …

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A higher fine aggregate content affected the compressive strength of mixtures with a constant w/c ratio. Although there was not a big difference in the compressive strength of concrete mixtures, there was a slight shift in the increment of strength after …

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The optimum cement contents for both concretes are on the basis of equal mazimum size of coarse aggregate and equal compressive strength. The comparison has shown that much less cement is required for concrete with gap-graded aggregates than its continuously graded counterpart with approximately the same workability.

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Size of Coarse Aggregate. Materials that are large enough to be retained on the 4.7mm sieve size usually constitute coarse aggregates and can reach a maximum size of 63mm. The size of coarse aggregates affects several aspects of the concrete, mainly strength and workability, and the amount of water needed for the concrete mix.

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When its content is high, the flexural strength of the needle-shaped coarse aggregate is relatively low, and the bonding strength between the coarse aggregates decreases, which causes the strength of the concrete to decrease. For ready-mixed concrete, the high content of needles and flakes will make the coarse aggregates poorly shaped, thereby ...

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consumption peak for UHPC2 containing coarse aggregates is high and narrow, while for UHPC1 without coarse aggregate low and wide. The stabilisation time for UHPC2 was approx 2 minutes. The total time from dry mixing to discharging was approx 3.5 minutes. For UHPC1 the stabilisation time and the total time was about 3,5 and 5.5 minutes ...

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the high-strength SCC and HSC mixtures for a given ag-gregate type. Because the only significant variable be-tween high-strength SCC and HSC is the coarse aggregate content (10% difference in coarse aggregate content in the Myers et al. study), the volume of coarse aggregate had a negligible effect on the observed shear stress between the two ...

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Answer (1 of 3): The strength of concrete depends on the total surface area of aggregates, which has to be coated by cement and the voids in between the aggregate particles, which, again has to be filled with cement. As average particle size decreases, the surface area increases for an unit of co...

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Angular aggregates are used for higher strength concrete due to their good interlocking property and high bond strength. The workability of angular coarse aggregate is low, but this problem is minimized by filling voids with rounded or smaller aggregates.

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Structural lightweight concrete plays an important role in the construction industry, especially for the high-rise buildings. It can only be produced using lightweight aggregates. Oil-palm-boiler clinker (OPBC) is a solid waste from the oil palm

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High water absorption aggregates used for concrete pavements are also more susceptible to popouts and are less resistant to freeze-thaw cycles. The moisture content of aggregates can be measured using the moisture content of aggregate test detailed in BS EN 1097-5.

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Variation in the size of Aggregates changes the water demand, cement content, micro-cracking (strength) in concrete. It also effects pumpability, and durability of concrete. Grading of aggregates depends on the proportions of coarse and fine aggregate. If grading of aggregate is varied, it also changes cement paste content (cost economy), workability of the mix,

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smaller sized coarse aggregate produces higher strengths for a given water-to-cement ratio. In fact, it is generally agreed that, although larger coarse aggregates can be used to make high-strength concrete, it is easier to do so with coarse aggregates below 12.5 mm (Y, in.) (ACI 363-95).

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the feasibility of using copper slag as coarse aggregates in high-strength concrete. The effects of replacing limestone coarse aggregate by copper slag coarse aggregate on the compressive strength, splitting tensile strength and rebound hammer values of …

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Basalt Aggregate as Coarse Aggregate in High Strength Concrete Mixes P.RAMTEJA P.G Student Siddartha Group Of Educational Acadamy Tirupati. Abstract: Concrete innovation has been changing quickly and continually since its revelation. The way toward selecting appropriate elements of concrete and deciding their relative sums with the goal of ...

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2.1.3. Fine and Coarse Aggregates . Local mining sand was used as the fine aggregate, having a specific gravity, fineness modulus, water absorption, and maximum grain size of 2.68 g/m 3, 2.72, 0.97%, and 4.75 mm, respectively.The fine aggregate content was kept constant at 860 kg/m 3 for all mixes.. OPS were used as the coarse aggregate in this study.

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Two of the main problems encountered in flexible pavements are the stripping of coarse aggregates and the formation of rut depth due to increases in the volume of road traffic and heavy vehicle loads, especially in areas where speeds are low. The existence of rut depth also affects the comfort and safety of road users due to the water accumulation on the pavement surface and reducing tire ...

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As far as strength is concerned, higher aggregate strength would produce higher concrete strength provided that other controlling factors have been dealt with properly. 1. Maximum Aggregate Size. The maximum size of coarse aggregate is one of the factors that controls water demand to achieve certain work-ability.

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Coarse Aggregate Meaning. Aggregate which has a size bigger than 4.75 mm or which retrained on 4.75 mm IS Sieve are known as Coarse aggregate.. Origin Of Aggregates. The aggregates are generally acquired by blasting in stone quarries or breaking them by hand or by crusher machines.. The aggregates manufactured by machine-crushed consist of stones of various sizes …

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The densification of the interfacial transition zone allows for efficient load transfer between the cement mortar and the coarse aggregate, contributing to the strength of the concrete. For very high-strength concrete where the matrix is extremely dense, a weak aggregate may become the weak link in concrete strength.

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Higher maximum aggregate size lowers paste requirements, increases strength and reduces w/c ratios. However, excessively large aggregate tends to lower strength by reducing available bonding area. ASTM has limits for grading of concrete aggregates. Fineness Modulus-- a parameter for checking the uniformity of grading. Generally calculated for ...

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In general, smaller size aggregates have been shown to produce higher strength concretes, for a fixed w/(c+p) ratio. However, the use of the largest possible coarse aggregate may be an important consideration in terms of optimizing modulus of …

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1995). In ordinary strength concrete, the properties of coarse aggregate do not determine the concrete performance because their strength is significantly higher than the strength of mortar. On the other hand, in high-strength concrete, the coarse aggregate properties are important because of the improved mortar quality.

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1.Size of Coarse Aggregates: The size of the coarse aggregate depends on the use of the concrete is to be poured. For large-scale concreting operations without complex reinforcement, large aggregates of size 80 mm, 40 mm, 20 mm are used. For the simple construction of residential or other buildings, 20 mm is the maximum size will be used.

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Due to the large amount of antimony ore waste rock produced by perennial mining, the antimony ore waste rock is deposited in the open air and need high treatment cost. The goal of this study is to provide a possibility to utilize the antimony waste rock as a complete replacement for coarse aggregate in high strength concrete.

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The toughness and soundness test results on the recycled coarse aggregate showed higher percentage loss than natural aggregate, but remained within the acceptable limits.

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