Research On High-Strength Shale Aggregate's Preparation And Property For Aggregate Concrete

The main characteristic of high-strength aggregate is high strength, low absorbing water rate and good grade mix. The concrete made from high-strength aggregate has lighter weight, higher specific strength and better shock resistance etc. It has the remarkable technological economic benefits in the large span bridge and the skyscraper. As the important strategic place in the development of western regions, the large-scale bridge and skyscraper provide the broad market in the light aggregate concrete application at Chongqing. But the produce and the application of high-strength aggregate and high-strength aggregate concrete are still lack at Chongqing .This thesis's main purpose is to utilize shale resource of Chongqing to study suitable raw materials prescription on roast the high-performance aggregate and the high-performance aggregate roast technology parameter and different admixture impact on performance of the aggregate. This thesis study the absorbing water rate of the high-strength aggregate and the high-strength lightweight aggregate concrete also.The result of the study shows:(1)The shale from Jingjin Congqing and Fuxing Yungyan suit the production of high-strength aggregate.(2)When carry on the hot processing technology of the aggregate, lengthening the time of preheating and adopt fast low-temperature calcinations may raise the intensity of the aggregate.(3)It is very helpful to producing the high-performance shale aggregate by adding the right amount fly ash in the shale materials.(4)At Chongqing Yunyang Chuangxin building materials factory , the shale aggregate characteristic with high-performance aggregate is produced out by the author. The packing density is 835 kg/m3; tube press strength is 8. 1Mpa; strength grade is 40Mpa; water absorption rate in atmospheric pressure is 4.8%.(5)The pressure size, press time, w/c ratio and the moisture content of the aggregate affect the water absorption rate of the shale aggregate .(6)By the way of controlling cement content, w/c ratio, sand ratio correctly and adding superplasticizer admixture, we have been produced lightweight aggregate concrete which apparent density is 1760 kg/m3-1920 kg/m3, 28d compressive strength is 50~60MPa , Initial slump degree is 160-210mm and has the better jobperformance by using the shale aggregate made by ourselves.