低成本、低碳SHCC的制备及力学性能研究

Study on preparation and mechanical properties of low-cost and low-carbon SHCC

为了解决传统应变硬化水泥基复合材料(以下简称SHCC)高成本和高水泥用量的问题,用国产PVA纤维和河砂分别全部取代传统SHCC中广泛使用的进口PVA纤维、超细石英砂,并用粉煤灰等质量部分取代50.0%、62.5%、75.0%的水泥,制备了低成本、低碳SHCC,研究了粉煤灰掺量和砂胶比对SHCC力学性能的影响,并用SEM观察了其微观形貌。结果表明:用国产PVA纤维和河砂可以制备出低成本、低碳SHCC;随着粉煤灰掺量的增加,试件的抗压、抗折和拉伸强度降低,但延性提升;随着砂胶比的增加,试件的抗压、抗折强度降低,拉伸强度提高,延性降低。

In order to solve the problem of high cost and high cement content in traditional strain hardening cementitious composites(SHCC),the low-cost and low-carbon SHCC was prepared by partly replacing imported PVA fibers and ultrafine quartz sand widely used in traditional SHCC with domestic PVA fibers and river sand,respectively,and replacing 50.0%,62.5%and 75.0%of cement with fly ash.The effects of fly ash content and sand-binder ratio on the mechanical properties of SHCC were studied,and the microstructure was observed by using SEM.The results show that the low-cost and low-carbon SHCC can be prepared by using domestic PVA fibers and river sand.With the increase of fly ash content,the compressive,flexural and tensile strength of the specimen decrease,but the ductility increases.As the sand-binder ratio increases,the compressive and flexural strength of the specimen decrease,the tensile strength increases,and the ductility decreases.