TEST STUDY ON THE RECYCLED AGGREGATE AND RECYCLED AGGREGATE CONCRETE REGENERATED FROM WORN CEMENT CONCRETE PAVEMENT

Regenerate utilization of worn cement concrete is the key technical problem to be solved in the traffic field The cement concrete pavements built long ago are in durative disrepair The study is aimed at the worn cement concrete which can not be re-used Recycled aggregates were obtained according to the practical technics of regenerate, and then test studies on the aggregates and recycle aggregate concrete were carried out Test results show recycled fine aggregate is about 26% of recycled aggregates, and substantive sand pulps are adhere on the surface of recycled while the distinct crackle appears on this sand pulp surface relative to the natural aggregate, one of the remarkable characters of the recycled aggregate is that the inartificial water ratio is relatively low and the water absorbing ratio can reach 4% 12%, and the water-absorbing ratio increased while the fine grain increased The second remarkable characters of recycled coarse aggregate is that the weared stone value and crushed stone value of recycled coarse aggregate are both higher, the Los-angeles weared stone value is 32 7, the crushed stone value is 26 5 So, the recycled aggregate can not meet the criterion, but after being mixed with 40% natural aggregates, it does meet the requirements The mixture ratio test results proved that based on the dosage of cement we can through reduce water cement ratio and augment water quantity to improve the working performance of recycled concrete The failure form of recycled concrete is inline with natural concrete failure The recycled aggregates can absolutely be used in cement concrete under C50