Novel roller-compacted concrete for dams and preparation method thereof

Abstract

The invention discloses novel roller-compacted concrete for dams and a preparation method thereof. The novel roller-compacted concrete comprises the following components in parts by weight: 60-110 parts of water, 51-59 parts of cement, 70-120 parts of fly ash, 500-700 parts of river sand, 1400-1500 parts of coarse aggregates, 0.876-1.46 parts of a set retarding superplasticizer and 0.02-0.04 part of an air-entraining agent. The preparation method of the novel roller-compacted concrete comprises the following steps: firstly, crushing river sand by using a crusher so as to form a finished sand product; and mixing the finished sand product with other components so as to form the novel roller-compacted concrete. According to the invention, the quality of sand is improved, no water source is consumed, no dust is produced, and an effect of energy conservation and environmental protection is achieved.

Description

technical field [0001] The invention relates to the technical field of water conservancy engineering construction, and more particularly relates to a novel roller compacted concrete for dams and a preparation method thereof. Background technique [0002] Roller compacted concrete is a dry hard cement-poor concrete, which is made of dry hard concrete without slump by mixing Portland cement, pozzolanic admixtures, water, admixtures, sand and grading-controlled coarse aggregate. Use the same transportation and paving equipment as for earth-rock dam construction, and use vibrating rollers for layer compaction. Roller compacted concrete dams not only have the characteristics of small concrete volume, high strength, good anti-seepage performance, and the overflow of the dam body, but also have the advantages of simple, fast, economical construction procedures for earth-rock dams, and the use of large general-purpose machinery. [0003] The construction speed of roller compacted c...

AI Technical Summary

Problems solved by technology

[0004] First, the quality of the stones mined from the stone quarry is poor and the reserves are small, and the artificial sand produced cannot meet the construction requirements in terms of quality and quantity;

[0005] Second, the surrounding area lacks enough artificial sand to meet the large amount of continuous construction of the dam, and most of the artificial sand is poorly graded, with a high content of coarse particles and stone powder, and less intermediate gradation particles, which cannot meet the needs of RCC construction. Require;

[0006] The third is that it is difficult to transport bulk purchased materials such as cement, fly ash, and gravel, which increases the cost;

[0007] Fourth, if the downstream river sand is used, its resources are abundant, but due to the long-term erosion of the river sand and natural deposition, the loss of fine particles is serious, there are many coarse particles, and the gradation is poor, and the content of stone powder is only 2%~3 %, the fineness modulus FM is relatively high, reaching a maximum of 3.8, which has exceeded the specification requirements, and does not need to be directly used for mixing dam concrete, and needs to be treated;

The stone powder content of the sand can be increased through the technical measures of adding stone powder to the river sand, but the mixing process of stone powder and river sand is complicated, and the blending quality is difficult to guarantee; on the other hand, according to the test results of the mix ratio, the amount of stone powder per square concrete has a gap of 137kg , that is, a total of 27,400 tons of stone powder is required. According to the market survey of sand and gravel materials, the supply of stone powder is difficult

[0009] Chinese patent CN100450964C discloses a kind of micro-slump concrete and its construction method for roller compacted concrete dams, which consists of cement, fly ash, coarse aggregate, fine aggregate, retarding superplasticizer, air-entraining agent It is prepared with water. Compared with conventional concrete, cementitious materials are added to greatly improve the slump of concrete, but its compressive and flexural properties are not good.

Chinese patent application CN101168482A discloses a roller-compacted high-performance concrete and its preparation method, which is made of cementitious material, aggregate, water and external water-reducing agent. The concrete and its preparation method solve the problem of insufficient durability of concrete problems, but a large amount of fly ash is used in its formulation, which increases the cost of concrete preparation

Moreover, the compressive and flexural properties of the concrete prepared by this prescription and process are not ideal

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