Tests And Research On Bond Behavior Between Steel Bar And Recycled Aggregate Concrete

Nowadays, More and more Scholars are studying for recycled aggregate concrete, because recycled aggregate concrete can play a great role on Environmental protection and economy. With the development of recycled aggregate concrete, bond behavior between steel bar and recycled aggregate needs to be further experimented on.Based on the above, The following research work was carried out. First, various physical and mechanical properties of recycled coarse aggregate(RCA)were investigated according to Pebble and crush stone for building (GB/T 14685-2001). The test results in dicate that the RCA has the reputation of low density, high water absorption and porosity, low sterngth and soundnesscompared with those of natural coarse aggregates(NCA). Secondly , five kind s of Mixture ratio for concrete were designed and performed. In Experimenta 1 work, we determinated the Construction performance of concrete like Slum p, Apparent density, compressive strength etc. the results of Mixture ratiofor recycled aggregate concrete demonstrat that recycled aggregate concret e could be used in new engineering . Third, the bonding mechanism between s teel bar and recycled aggregate concrete is discussed based on the pullout test results of 162 specimens. Based on the experimental work, we come to Conclusion that: the Load-Slip Curve of RCA concrete pull-out specime n is like that of NCA concrete, Surface features of steel bars has a great influence on bond strength, under the same condictions, Bond strength betw een hot rolled ribbed steel bars and RCA concrete is about 10 times of hotrolled plain steel bars. By the analyses of the influence of compression st rength, anchorage length and bar diameter on anchorage behavior, the formul as of the characteristic strength value and characteristic slip value are a ttained by means of statistical. In this experiment, we found that bond stre ngth of RCA concrete is as good as NCA concrete, so we Propose that anchora ge length of hot rolled ribbed steel bars could be taken the same of NCA co ncrete. The other Proposal is , it must be taken reliable Mechanical anchor m easure when we use hot rolled plain steel bars in RCA concrete.