乌兰布和沙漠砂制备高延性水泥基复合材料的力学性能

Mechanical Properties of Engineered Cementitious Composites Prepared with Sand in Ulanbuh Desert

使用内蒙古乌兰布和沙漠砂完全代替微石英砂配置了高延性水泥基复合材料(ECC),并以砂胶比为变量,对其抗压强度、抗拉强度、抗剪强度以及抗弯强度四个方面的力学性能展开了全面的研究。抗拉试验后进一步对纤维断面使用扫描电镜(SEM)进行了观测,并采用X射线衍射分析(XRD)方法研究了沙漠砂的物质组成。结果表明,以沙漠砂配置的ECC,在相同骨料含量的条件下,其抗压强度、抗拉强度、抗剪强度以及抗弯强度均与微石英砂配置的ECC接近,延性约为微石英砂ECC的一半。除抗剪强度外,沙漠砂ECC其他各项性能均随砂胶比增大而提高,优化配比设计的沙漠砂ECC延性能够达到微石英砂ECC的水平。

Engineered cementitious composites(ECC)were completely replaced by Ulanbuh desert sand from Inner Mongolia to conduct a comprehensive study on the mechanical properties of its compressive strength,tensile strength,shear strength and flexural strength.The sand-binder ratio was set as the variable.X-ray diffraction(XRD)was employed in this study to analyze the composition of the desert sand,and scanning electron microscope(SEM)was used to observe the cross section of fiber after the tensile test.The results show that the compressive strength,tensile strength,shear strength and flexural strength of the ECC prepared with desert sand are similar to the ECC prepared with microsilica sand,and the ductility of desert sand ECC is about half of microsilica sand.Except for the shear strength,all of other properties of desert sand ECC are improved with the increase of sand-binder ratio.The ductility of desert sand ECC designed with optimized mix proportion reaches the level of the microsilica sand ECC.