关键词: 破坏形态;混杂纤维;抗弯性能

Abstract: Taking the content of silica fume and the content of mixed fiber as the test parameters , one ordinary concrete beams were used as the control group , and three beams with different contents of silica powder and two beams with the different volume fraction of hybrid fiberwere used as the experimental group, the flexural performance of modified recycled concrete beams is analyzed , the results show that failure process of modified recycled concrete beams and ordinary concrete beams has obvious four stages of the process , and its basic mechanical process also accord with flat section assumption; And with the addition of silica fume and hybrid fibers , the flexural performance of the modified recycled concrete beams is enhanced , which cracking resistance and ultimate bearing capacity is better than that of recycled concrete beams is ordinary;According to the standard , the ultimate bearing capacity of the normal section is consistent with the experimental value , and the modified recycled concrete can be designed according to the standard , which provides a reference for engineering practice .

Key words: failure mode;hybrid fiber;flexural behavior