聚丙烯纤维再生混凝土收缩性能研究

Study on the shrinkage properties of recycled concrete of polypropylene fibers

使用低强度的再生混凝土材料制备预制墙板,对扩大再生混凝土的应用领域、提高再生混凝土的利用率有着积极的意义。将再生混凝土中掺入引气剂(0、5%、10%)和聚丙烯纤维(0、1.2 kg/m^(3)),对其进行抗压强度和收缩性能试验,分析了引气剂掺量和聚丙烯纤维掺量对于再生混凝土自重、抗压强度和收缩变形的影响。结果表明:加入引气剂可减轻自重,但抗压强度会随着引气剂掺量的增加而降低,复掺引气剂与聚丙烯纤维会明显改善再生混凝土的收缩性能。试验结果为将再生混凝土应用于预制混凝土墙板打下基础。

The use of low strength recycled aggregate concrete materials for the preparation of precast wall panels has a positive significance in expanding the application area of recycled concrete and improving the utilization rate of recycled aggregate concrete.The recycled aggregate concrete was mixed with air-entraining agent(0,5%,10%)and polypropylene fiber(0,1.2 kg/m^(3)),and the compressive strength and shrinkage performance tests were conducted to analyze the effects of air-entraining agent dose and polypropylene fiber dose on the self-weight,compressive strength and shrinkage deformation of the recycled aggregate concrete.The results show that the addition of air-entraining agent can reduce the self-weight,but the compressive strength will continue to decrease with the increase of air-entraining agent.The compounding of air-entraining agent with polypropylene fiber will significantly improve the shrinkage performance of recycled aggregate concrete.The test results lay the foundation for the application of recycled aggregate concrete to precast concrete wall panels.