【作者】 陈雪； 孙乾耀； 崔立山； 徐春明；

【Author】 CHEN Xue SUN Qianyao CUI Lishan XU Chunming (State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249;China)

【机构】 中国石油大学重质油国家重点实验室；

【摘要】 高模量的聚乙烯醇纤维可代替钢筋增强水泥基材料的韧性,使其呈现假应变硬化和多缝开裂的特征,从而改善结构的耐久性。通过三点弯曲试验得出不同配比下纤维增强水泥基复合材料(ECC)的抗弯曲特性。结果表明,水灰比越大,ECC的抗弯强度越小,但水灰比小,会降低基体流动性能,不利于施工操作;随着纤维质量分率的增大,ECC的抗弯性能先增后降,纤维的长径比越大,弯曲性能越好。更多还原

【Abstract】 Concrete is characterized by strong compressive strength,but is relatively weak in tension and shear.Worse tough- hess of cementitious composites are the dominant reasons for incidental crack and deterioration of durability for reinforced eonerete structures.For structures that require flexural strength for resistance to bending moments,reinforcing steel-rebar-is embedded in the concrete,but it breaks easily under bending without reinforcing steel.In this paper,the experimental results indicated that the due- tility of the cementitious composites could be enhanced by the high elastic modules Polyvinyl Alcohol (PVA)fiber.In addition,the characteristics of strain hardening and multiple cracks were presented.Consequently,the durability of ECC structure could be im- proved.Via three points bending test study the impact of synthesis recipe on the ECC’s flexural strength had been explored.The experimental results indicated that the ECC flexural strength is higher at smaller water amount.In general the ECC curving perfor- mance increases with higher ratio of fiber length to diameter,but there is a critical value.更多还原