关键词: 弯曲韧性;腐蚀;干湿循环;长期浸泡;硫酸盐

Abstract: In order to study the flexural properties of hybrid fiber reinforced concrete after sulfate corrosion, the sulfate dry-wet cycle corrosion and long-term immersion corrosion tests were carried out to study the effect of different content of polyethylene fibers (PE) and polypropylene crude synthetic fiber (HPP) concrete.Then, based on the three-point bending test, the flexural toughness of mixed fiber concrete before and after sulfate corrosion and the optimum fiber content were compared with ASTMC1018 of USA and ORS of Austrian standard.The results show that the failure mode of concrete is changed by the incorporation of fiber, the maximum load and deflection of the concrete are obviously increased, the I5、I10、I20、R5,10and R10,20 of concrete are obviously improved, and the toughness level is also obviously higher ordinary concrete.The flexural toughness of the concrete with different fiber content in the presence of sulfate has been damaged to varying degrees.The flexural toughness of the concrete under the wet and dry cycle corrosion condition is more serious than that under the long-term immersion corrosion condition.When the content of polyethylene (PE) and polypropylene crude synthetic fiber (HPP) is between 0.8％ and 1.2％, the concrete exhibits good corrosion resistance and flexural toughness, after 450 d long immersion corrosion, I5、I10 and R5,10 are increased by 32.2％, 19.6％ and 6.8％ respectively.

Key words: flexural toughness;corrosion;wet-dry cycle;long-term immersion;sulfate