Study Of Concrete On Durability With Desert Sand And Ecological Fibers

With the construction of large-scale infrastructure projects, the concrete can be widly used because of its superiority, the building materials industry has been gradually brought up, the sand can not to meet building needs whether in the in the perspective of the economy, quality, reserves, or sustainable development, is unable. Ningxia and neighboring ragion like Neimeng and Gansu,have rich desert sand resource, Today,we promote " local conditions, local materials " actively,Exploit and use local desert sand, and apply it to the construction project, turning waste into treasure, not only help to curb desertification, reducing desertification, loss, make a contribution to the ecological environment and promote the harmonious development of man and nature, but also reduce the project cost, with far-reaching social significance and value.This paper analyzes the use of desert sand concrete’current situation ang conclusion previous studies.On this basic,this paper seleceted local desert named Maowusu;desert sand of Ningxia to replace part of velvet for concrete shrinkage cracks easily, abrasion poor performance issues,put forward through incorporation of eco-fiber, using its special enhancements to improve the durability of concrete desert sand. By orthogonal test and shrinkage cracking performance, impact and abrasion resistance, frost resistance comparison test, study the ecological influence on the mechanical properties of fiber concrete desert sand, crack shrinkage properties, abrasion and frost resistance and performance To investigate the mechanism of its effects, the test results were as follows;(1) by orthogonal test optimization and comprehensive analysis, the optimal ecological fiber reinforced concrete with desert sand ratio A1B2C2D1E3, water-cement ratio0.29-0.32, ash content range of20-25%replacement rate, replacing the desert sand rate of20-30%,36-40%sand ratio, eco fiber content is0.9-1.2kg/m3.(2) through28d physical and mechanical properties test results show that by incorporating eco-fibers, the optimal set of tension and compression ratio significantly higher than other groups,22.54%higher than the reference group. The greater the tension and compression ratio, the better the overall reaction toughness of concrete, can be seen, ecological fiber reinforced concrete with high tensile toughening effect.(3) Eco-fiber can significantly improve the performance of concrete frost in the early freeze-thaw cycles, the internal defects in the concrete of the original than its initial dynamic modulus of the negative impact of fiber significantly positive effects:With the increase of the number of freeze-thaw, fiber concrete action to improve the performance of frost became clear, when freeze-thaw200times, the relative dynamic modulus desert sand is about eco-fiber reinforced concrete120%of plain concrete, concrete mixed with eco-fiber is effective to improve the level of antifreeze one of the ways.(4) can be derived from the abrasion resistance test:the reference group, no fiber group, the best group wear rates were1.4%,2.0%,1.5%, after the incorporation of the desert sand to make concrete abrasion performance decreased However, after the incorporation of eco-fiber abrasion performance of the concrete desert sands more significant improvement compared with the non-fiber group, the abrasion strength increased by33.2%, the wear rate decreased by0.5%.(5) concrete shrinkage tests showed:whether shrinkage or shrinkage of concrete is much higher than the reference group of the other two fibers mixed with concrete and desert sand, shrinkage of up to914.9x10-6, the maximum value of shrinkage9.12, shrinkage greater growth. No minimum shrinkage fiber group1d,7d and optimal group near flat, after a significant increase in post-shrinkage greater than the optimal set of concrete. Description ecological fibers can improve the performance of concrete desert sand late contraction.