工程水泥基复合材料的制备及力学性能

Preparation and mechanic behaviors of engineered cementitious composites

为制备良好的工程水泥基复合材料(engineered cementitious composites,ECC),解决纤维成团以及拉伸试验中不出现应变硬化和多裂缝等问题,提出掺入硅灰的制备方法,并采用整浇方式以确保纤维的良好分散.分析研究了3种试件的拉伸试验和部分配合比的立方体抗压试验.结果表明:掺入硅灰能较好解决纤维成团问题;整浇有利于应变硬化的发挥和多裂缝开展;水胶比增大和水泥掺量减小(即粉煤灰掺量增大)能降低试块的抗压强度;3种类型的拉伸试件均在试验中出现了良好的应变硬化现象.

In order to produce engineered cementitious composites,solve the problem of fiber balling and ensure the phenomenon of strain hardening and the multiple fractures in the tensile test,a method of adding silica fume and using integral casting to protect fiber dispersion is proposed.Tests of tensile specimens with three different kinds and compressive strengths of some mix proportion are analyzed.The results show that silica fume can solve the problem of fiber balling better.Integral cast has advantageous to the occurrence of strain-hardening and multiple-crack.Compressive strength decreases with the increasing of water-cement ratio or cement content（fly ash content increases）.Strain hardening phenomenon all occurs in the tensile tests of three kinds specimens.