纤维水泥浆界面区对FA-SHCC力学性能的影响

Influence on the mechanical performance of FA-SHCC by its structure of interfacial zone between fiber and matrix

对水泥浆基材进行改性是提升应变硬化水泥基复合材料(SHCC)力学性能的一个重要手段.本文利用粉煤灰对SHCC胶凝体系进行改性,改善了PVA桥联功能和SHCC的力学性能.并利用扫描电镜(SEM)和电子探针(EDS)等方法分析纤维-水泥浆界面区(ITZ)的结构和产物.试验结果表明PVA纤维与水泥浆结合较紧密,阻碍了多重开裂的产生;而粉煤灰的加入可以明显改善FA-SHCC的直拉和弯曲性能;对ITZ的EDS观测发现粉煤灰的加入可以改变SHCC的ITZ水化产物和微观结构,提高了桥联作用,改善了力学性能.

The modification of matrix is an important method to improve the mechanical properties of SHCC. The bonder system of SHCC is adapted by mixing of fly ash, then the fiber bridging function and mechanical properties are hereby developed. In addition, the structure and hydration products of interracial zone （ITZ） between fiber and matrix are analyzed by means of SEM and EDS. The experimental results indicate that the high chemical bond between fiber and matrix prevent the occurance of multi-cracking. However, the mixing of fly ash improves tensile and bending performance of SHCC. Furthermore, the EDS inspection and analysis discover that fly ash changes the hydration products and micro-structure of ITZ, it improves the bridging function and mechanical properties of SHCC.