双掺钢纤维和聚乙烯纤维的水泥基复合材料的抗折性能

Flexural Properties of Double-doped Steel Fiber and Polyethylene Fiber on Cement-based Composite Materials

采用钢纤维和聚乙烯纤维(PE)双掺的方式制备了一种高韧性水泥基复合材料(UHTCC),在PE纤维固定掺量取1%时,通过三点抗折试验,研究了不同钢纤维长度(6mm、10mm、13mm)和不同掺量(0、0.3%、0.6%、0.9%)对UHTCC抗折性能的影响,同时对UHTCC的强度增强机理进行了分析。结果表明:相较于单掺PE纤维的试件,钢纤维的掺入能够显著提高试件的抗折强度。UHTCC试件的破坏形态为延性破坏,且随着钢纤维长度和掺量的增加,裂缝数量和分布范围逐渐增大;相较于短纤维,长钢纤维对UHTCC的增强效应更优;UHTCC的抗折性能随钢纤维掺量的增加而提高,6mm钢纤维试件在掺量为0.9%时抗折性能最优;10mm钢纤维试件的抗折性能在掺量为0.6%时达到峰值;13mm钢纤维试件抗折强度随掺量增加而提高,但挠度变形减小。

The hybrid mode of steel fiber and polyethylene fiber(PE)has been adopted to produce a novel high toughness cementitious composites(HTCC).The flexural behavior of HTCC has been experimentally investigated with consideration of different steel fiber lengths(6mm,10mm,13mm)and different contents(0,0.3%,0.6%,0.9%).Standard three-point flexural test was carried out and the PE volume percentage was a constant of 1%for all specimens.The results show that the incorporation of steel fiber can significantly improve the flexural strength of the specimens compared with the specimens with single PE fiber.The failure mode of UHTCC is ductile failure,and the number and distribution range of cracks increase with the increase of steel fiber length and content.Compared with short fiber,long steel fiber has better enhancement effect on UHTCC.The flexural performance of UHTCC increases with the increase of steel fiber content,and the flexural performance of 6mm steel fiber specimen is the best when the content is 0.9%.After the content of 10mm steel fiber specimen reaches the peak point at 0.6%,the flexural performance of the specimen decreases.The flexural strength of 13mm steel fiber specimens increases with the increase of content,but the deflection deformation decreases.