Based On The Comprehensive Utilization Of Construction Waste Recycled Aggregate Concrete

According to statistics, currently the amount of construction wastes what produced from constructing new buildings and demolishming old buildings has reached to 2.400.000～3.600.000 ton annual in china. While,the output of commercial concrete we manufactured in 2004 is 2.840.000 cubic meter in our country, what consumed our natural sandrock 500.000.000 ton at least. The amount of produced construction wastes and consumed natural sandrock is so large,that can be causing a great deal of construction garbage stacked and more and more sandrock excavated, and finally it will pollute and devastate our entironment and having serious ecological consequences. Recycling construction wastes can not only resolve the problem of a great deal of construction garbage stacked polluting our entironment but also reduce the demand of natural sandrock, having the good economic performance, social performance and environmental protection performance.Therefore making construction wastes to be recycled is very necessary.In this paper we outlined the present situation and development trends of reused construction waste and at home and abroad, designed several intensified methods, examinated the pressive strength , flexutal strength, static modulus of elasticity ,penetrability of concrete intensified and economic Analysis was done in the last. The research conclusions showed intensifying recycled aggregate is technically feasible, economic returns of making use of recycled aggregate is very good too.Expetiments proves that when mix recycled coarse aggregate that is not intensified into concrete, strength of concrete does not show a big drop, so in this research the substitution rate of recycled coarse aggregate to natural coarse aggregate setted is 100%. But recycled thin aggregate will influence the strength of concrete very seriously, through research and contrast, the substitution rate of recycled coarse aggregate to natural coarse aggregate in this paper setted is 20%.In this paper we take four kind of measures to intensify recycled aggregate as follows.①mechanical friction;②"cement + fly ash"solution;③water glass solution; ④"water glass + fly ash" solution. We researched these measures how to affect pressive strength, flexutal strength, static modulus of elasticity, penetrability of concrete. The finial experimental data shows that all kinds of intensifying measures all can improve performance of recycling aggregate concrete, but take measure of number 3 is best. Using measure of number 3 can bring about an advance of pressive strength 50%(28d), 47.4%(90d), and flexutal strength 26.7%(28d), 33.5%(90d), and static modulus of elasticity 25.3%(28d). It also can bring down penetrability of concrete 41.5%(28d), improve performance of recycling aggregate concrete. So using "water glass + fly ash" solution to intensify recycled aggregate will be an important methods to realize high -strength for the recycled aggregate concrete, it should be further researched and extended in the future.