Preparation For Improving Strength And Mechanical Performance Testing Research On Concrete Made With Recycled Concrete Aggregate

Mechanical property tests and deformation behavior of recycled aggregate concrete has been studied systematically in the experiment to drive the applications of high strength recycled concrete in the engineering field.The variable parameters considered in test beams are aggregate replacement,water-binder ratio and the dosage of cementing agent on the base of recycled concrete coordinating optimal proportion.The study on preparation and performance of high strength concrete was carried by analyzing 36 set of test specimens in four different aggregate replacement inculding 0%,30%,70%,100%,three different water-binder ratio inculding 0.28,0.32,0.36 and three different cementitious material consumption inculding 520kg/m3,570kg/m3,620kg/m3.There are three cube specimens and three prism concrete test specimens for a total of 216 test specimens.The main conclusions were as follows:1.High strength recycled concrete was made in this experiment by low water-binder ratio,high cementitious material consumption and admixture with mineral substance in four different aggregate replacement inculding 0%,30%,70%,100%.The compressive strengths of Recycled aggregate concrete can attain C80 when the recycled aggregate replacement rate reaches 100%.The results showed that it could be possible to compound high strength recycled coarse aggregate.2.The water-binder ratio has become a principal factor in several strategic factors,such as aggregate replacement and the dosage of cementing agent,of influencing the compressive strengths of Recycled aggregate concrete.That is the compressive strength of recycled aggregate concrete will show decreasing trend with the increased water-binder ratio.3.Better strength results and economic benefits in the practical engineenng can be obtained by higher water-binder ratio and appropriate recycled coarse aggregate replacement percentage in the preparation of high strength recycied concrete.4.The stress-strain curve of recycled aggregate concrete showed that vegetation spatial pattern had a close relationship with normal concrete. The dimensionless complete stress-strain curve of recycled aggregate concrete manifested that high strength recycled concrete had significant brittle properties compare with normal concrete.5.In the respect of deformation properties,the most comfortable parameters of ductility factor varied for different water binder ratio and the dosage of cementing agent levels,with the increased recycled coarse aggregate replacement.The test specimens of manifested slightly decreasing trend with high the dosage of cementing agent consumption,but it showed the opposite tendency for 100% recycled coarse aggregate replacement.6.Laws for the energy dissipation coefficient and ductility factor development was basically in line with different aggregate replacement, water-binder ratio and the dosage of cementing agent.