Experimental Study On The Compression Strength Of Recycled Concrete And Ordinary Concrete With Artificial Sand Containing Stone Powder

one of the methods to solve the problem that it is the growing shortage of the natural sand resources is reasonable to use artificial sand instead of natural sand, which is a by-product in the production of gravel coarse aggregatethe. However, the quality of concrete with artificial sand is affected by the defect of the artificial sand containing a large number of stone powder. At the same time, in order to recycling use waste concrete, the compression strength of recycled concrete and ordinary concrete with artificial sand containing powder should be studied, which is by the natural gravel aggregate, recycled coarse aggregate crushing waste concrete with artificial sand combination preparation.In order to study on different artificial sand replacement rates and different powder contents of artificial sand effect on the workability、the compressive strength and the peak strain of concrete, considering two strength grades (C35, C45) and the different artificial sand replacement rates (0%、30%、50%、70%、100%) corresponding to the different powder content of artificial sand (0、5%、10%、15%、20%) as variables factors, forty-eight RCC35、eighteen RCC45and forty-eight NC35test blocks are made.The main conclusions for the test study can be drawn as follows:(1) When artificial sand replacement rate is less, the gradation is more close to the natural sand and also is better; When artificial sand replacement rate is larger, The fineness modulus are larger and particle is more thick; When the content of stone powder is higher in the same artificial sand substitution rate, artificial sand gradation is better.(2) When the content of stone powder less, the slump of RCC35and NC35rose; When the content of stone powder higher, the slump of RCC35and NC35decline. In line with rational design and selecting the ratio conditions, the workability of RCC35and NC35can be satisfactory.(3) The failure process of RCC35and NC35is as with ordinary concrete: the elastic, elastoplastic damage and experience stage. From the analysis of block failure interface, splitting is from the coarse aggregate and the new, the old gel interface, even directly through undisturbed gravel aggregate internal split.(4) The compressive strength of RCC35and NC35is greatly influenced by stone powder content. The compressive strength of RCC35and NC35containing powder were larger than those uncontaining in the same artificial sand substitution rate; the strength of RCC35and NC35increases with the increase of the artificial sand substitution rate in different artificial sand substitution rates, but the numerical optimal stone powder content of both are slightly different. In contrast, the numerical optimal stone powder content of NC35is higher than RCC35.(5) Effect of artificial sand replacement ratio on the compressive strength of RCC35and NC35is basically the same. In the absence of powder case, the regularity of artificial sand substitution rate for compressive strength of RCC35and NC35is that low and high replacement rate relatively have high strength, intermediate range of a replacement rate relatively have low strength. After adding powder, when the stone powder content is low, if artificial sand replacement rate is higher, the concrete strength is lower; when the stone powder content is high, it is opposite.(6) Effect of fineness modulus on the compressive strength of RCC35and NC35is basically the same:the concrete strength increases with decreasing of fineness modulus. The proposed optimal fineness modulus should be controled in the range of2.6-3.0.(7) In the artificial sand replacement rate and powder content for the peak strain of RCC35and NC35terms, effects of low and high content of stone powder content is opposite:when the stone powder content is less than5%, if artificial sand replacement rate is higher, the peak strain of concrete is less, which its ability to withstand deformation is the lowest; when the stone powder content reaches20%, it is opposite.(8) In the stone powder content for the RCC35�'�NC35peak stress and peak strain terms, in the case of the optimal content of stone powder, no matter how much the artificial sand replacement rate is, RCC35�'�NC35peak stress increases, the peak strain also increases at the same time.