Recycled Aggregate Concrete And Its Performance Study

This thesis mainly carried out on the mechanical properties and durability of the recycled concrete experimental study and experimental study on reinforcement of recycled coarse aggregate processing.On the basic mechanical properties and durability of recycled concrete test,this paper designs the C30,C40,C50 strength grade three,in the same proportion of cases,the selection of six kinds of quality such as recycled coarse aggregate replacement of natural aggregate,respectively,0%,20%,40%,60%,80%,100%,the compressive and freezing-thawing resisting block is 100mm*100mm*100mm standard cube,block,permeability test size is 175 mm in diameter,top of the mouth under 18 mm in diameter,150 mm high.The test results show that the compressive strength of recycled concrete generally on the rise with the increase of the trend,and increase obviously,mostly in more than 10%;Regeneration and C50 concrete when less than 40% recycled coarse aggregate content,ditto,when replace rate is more than 40%,with the increase of replacement ratio,the compressive strength but lower Freezing-thawing resisting performance difference with ordinary concrete,even better than that of ordinary concrete with water cement ratio;Permeability resistance along with the increase of recycled coarse aggregate replacement ratio is on the rise,are stronger than the contrast of the normal concrete.Low intensity level of recycled concrete can be made of more than 20 Mpa waste concrete made from recycled coarse aggregate,the mixture ratio remains unchanged,fresh concrete were mechanical strength will be because of the improvement of mechanical properties of recycled coarse aggregate and improve its product function increases.Recycled coarse aggregate performance study is to analyze the physical and mechanical properties of recycled coarse aggregate,comparing with natural coarse aggregate,and carries on the modification of test.The results show that the water absorption of recycled coarse aggregate and crushing index were greater than natural coarse aggregate,and the apparent density is less than natural coarse aggregate;Interface structure characteristics of recycledconcrete is analyzed.this thesis adopted the outside interface agent,interface agent mixed with cement,sodium silicate and sodium silicate cement and so on four kinds of modification methods,respectively to immersion and drying processing of recycled coarse aggregate,this process can reduce the porosity of recycled coarse aggregate,the reason is that the four kinds of modified slurry with recycled coarse aggregate of Ca(OH)2,C-S-H reaction,such as its products in the aggregate pore filling,made of recycled coarse aggregate griding micro cracks formed in the process of fixed to a certain extent,thus improving the from all walks of life to the bond strength in recycled concrete,to achieve the anticipated effect increased the strength of recycled concrete.Experimental results show that the interface agent outside mixing modification of the recycled coarse aggregate concrete,greatly strengthened its apparent density and crush index,compressive strength and durability performance have been enhanced obviously,shows the interface structure of recycled concrete can be improved through chemical grout.