关键词: 超吸水性聚合物, 高性能工程水泥基复合材料, 收缩性能, 抗压强度, 抗折强度, 拉伸性能

Abstract: High shrinkage is one of the bottlenecks limiting the large-scale engineering application of high performance engineered cementitious composites (HP-ECC). This work alleviated the shrinkage of HP-ECC by introducing superabsorbent polymers (SAP). The effects of different amounts of SAP on the compressive strength, flexural strength, tensile properties, autogenous shrinkage and dry shrinkage properties of HP-ECC were investigated. Scanning electron microscopy (SEM) was used to observe the changes in fiber surface morphology after stretching of HP-ECC caused by SAP. The results show that the addition of SAP reduces the compressive strength and flexural strength of HP-ECC and alleviates autogenous shrinkage and dry shrinkage, and the autogenous shrinkage and dry shrinkage decreases with the increase of SAP content. Moreover, SAP reduces the tensile strength of HP-ECC and increases the tensile strain of HP-ECC. The incorporation of SAP reduces the fracture toughness of the matrix, making it more prone to microcracks, thereby improving the strain hardening behavior and multiple cracking of HP-ECC. It is observed that with the increase of SAP content, the surface morphology of the fibers as they are pulled out of the matrix becomes smoother, indicating a decreasing in fiber matrix interface adhesion.

Key words: superabsorbent polymer, high performance engineered cementitious composite, shrinkage property, compressive strength, flexural strength, tensile property