不同纤维类型及尺寸对UHPC力学性能的影响

Study on Size Effect of Steel Fiber and PVA Fiber on Mechanical Properties of UHPC

为研究不同类型纤维及不同试件尺寸对UHPC的力学性能的影响,分别在UHPC中掺入钢纤维及聚乙烯醇纤维(PVA),并进行抗压强度、抗折强度、劈裂抗拉强度及四点弯曲性能试验。研究结果表明,在不同纤维体积掺量下,钢纤维及聚乙烯醇纤维UHPC抗压和抗折强度的尺寸效应十分明显;掺入钢纤维的UHPC抗压及抗拉强度改善效果均优于掺入聚乙烯醇纤维;钢纤维和聚乙烯醇纤维都可提高UHPC的劈裂抗拉强度和拉压比;钢纤维和聚乙烯醇纤维均可明显改善UHPC的弯曲韧性。

In order to study the mechanical properties of UHPC mixed with different types of fiber,steel fiber and polyvinyl alcohol fiber(PVA)were added into UHPC,and the compressive strength,flexural strength,splitting tensile strength and four point bending performance tests were carried out.The results show that the size effect of UHPC compressive strength and flexural strength of steel fiber and polyvinyl alcohol fiber is very obvious under different fiber volume fraction;The compressive strength and tensile strength of UHPC with steel fiber are better than those with polyvinyl alcohol fiber;Both steel fiber and polyvinyl alcohol fiber can improve the splitting tensile strength and tension compression ratio of UHPC;Both steel fiber and polyvinyl alcohol fiber can significantly improve the flexural toughness of UHPC.