高收缩率是限制高性能工程水泥基复合材料(HP-ECC)大规模工程应用的瓶颈之一。本文通过引入超吸水性聚合物(SAP)来缓解HP-ECC的收缩, 研究了不同掺量的SAP对HP-ECC抗压强度、抗折强度、拉伸性能、自收缩和干燥收缩性能的影响, 并采用扫描电子显微镜(SEM)研究了SAP对HP-ECC拉伸后纤维表面形貌变化的影响。结果表明, HP-ECC中掺入SAP后的抗压强度和抗折强度降低, 自收缩和干燥收缩得到缓解, 且自收缩和干燥收缩随SAP掺量的增加而降低。此外, HP-ECC的拉伸强度降低, 拉伸延伸率提高。SAP的引入降低了基体的断裂韧度, 使基体更容易形成微裂缝, 从而改善了HP-ECC的应变硬化行为和多缝开裂现象。随着SAP掺量的增加, 纤维从基体中拔出时的表面形貌越来越光滑, 纤维-基体界面黏结性能降低。

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 strengthflexural strengthtensile propertiesautogenous 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 shrinkageand the autogenous shrinkage and dry shrinkage decreases with the increase of SAP content. MoreoverSAP 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 matrixmaking it more prone to microcracksthereby improving the strain hardening behavior and multiple cracking of HP-ECC. It is observed that with the increase of SAP contentthe surface morphology of the fibers as they are pulled out of the matrix becomes smootherindicating a decreasing in fiber matrix interface adhesion.