基于高延性水泥基材料基层的抗裂性能研究

Study on Crack Resistance Based on High Ductility Cement-based Materials Base

为研究基层开裂问题,采用正交试验、荧光显微镜观察等试验方法,以提高延性为目的,采用硅酸盐水泥、聚丙烯酸钠、纤维、粉煤灰等材料,研发一种适用于基层的抗裂性水泥。结果表明水泥掺量4%、聚丙烯酸钠采用水泥的5%、掺PVA纤维6%的高延性水泥分布均匀、收缩应变小、抗裂性能佳。根据优选的高延性水泥的配合比,采用四点弯曲试验、改进的干缩试验、三点疲劳试验以及无侧限抗压强度试验,确认15%含泥量的混合料无侧限抗压强度达到7.7 MPa、疲劳次数超8800次,有效解决了“脏”集料在基层混合料的应用问题。

In order to study the basement cracking problem,using orthogonal test,fluorescence microscope observation and other test methods,in order to improve the ductility for the purpose,using portland cement,sodium polyacrylate,fiber,fly ash and other materials,to develop a crack resistance cement suitable for the base.The results show that the cement with 4%,5%of sodium polyacrylate and 5%high ductility cement with 6%PVA fiber has uniform distribution,small shrinkage strain and good crack resistance.According to the preferred mix ratio of high ductility cement,using four-point bending test,improved dry shrinkage test,three-point fatigue test and unlimited compressive strength test,confirm the unlimited compressive strength of 15%mud mixture reaches 7.7 MPa,fatigue times over 8800 times,effectively solve the problem of"dirty"aggregate in base mixture.