The Study On The Basic Properties And Volume Deformation Of Iron Tailing-steel Slag Aggregate Cement Concrete

At the beginning of the 21 st century,the sandstone resources in our country were in the transition stage,which were characterized by large demand,tight supply,depletion of natural reserves and continuous growth of consumption.At present,more than half the regions in our country have experienced the gradual reduction of natural sandstone resources,even no resources.Therefore,looking for new resources which meet the requirements of concrete to replace the tradition sandstone has become a necessary means to solve the problem of shortage of sandstone.With the development of industry,the emissions of iron tailing,steel slag and other solid wastes have increased with annual growth.Adding iron tailing and steel slag into concrete as concrete aggregate can not only solve the problem of the shortage of sandstone resources,but also can realize the effective utilization of solid waste,which has great benefits in economics and environment.The project was searched by using iron tailing instead of river sand as fine aggregate and steel slag instead of gravel as coarse aggregate(The respective replacement rates of iron tailing and steel slag are 0%?20%?40%?60%)to prepare iron tailing-steel slag aggregate cement concrete and carry out relevant experimental research on the working performance,basic mechanics performance and long-term volume deformation of 16 groups of concrete.The results show that:(1)With the increase of substitution of iron tailing and steel slag,the working performance of concrete decreased significantly;The increase of iron tailing dosage is unfavorable to the compressive strength of concrete,but steel slag can improve the compressive strength of concrete and mixed them into concrete,the compressive strength of concrete changes with a certain rule;when the replacement rate of iron tailing is 40%,the compressive strength of concrete deterioration is the most obvious.(2)steel slag is the main factors that cause the volume of concrete unstable and the specific performance is expansion;Because the surface roughness and better bonding with other aggregate,iron tailing can restrict the shrinkage of concrete,but not the more the better.(3)Numerical simulation results verify that with the increase of substitution of iron tailing and steel slag,the compressive strength of concrete changes with a certain rule and in the only consideration of improving the the compressive strength of concrete,it can choose a larger replacement rate.But considering volume stability of the concrete and other aspects,we should reduce the substitution rate of them.