聚丙烯纤维混凝土-沥青混凝土复合切口梁弯曲韧性研究

Flexural Toughness of Polypropylene Fiber Concrete over Asphalt Concrete Composite Notch Beam

对旧沥青路面进行铣刨处理后,加铺的白色罩面层多采用纤维混凝土,为了研究聚丙烯纤维和沥青层表面凿毛处理对复合切口梁弯曲韧性的影响,采用掺加聚丙烯纤维和对沥青层表面凿毛处理的高性能混凝土-沥青混凝土(AC-13)复合切口梁进行三分点加载试验,得到了荷载与挠度、裂缝张开距离之间的关系曲线,并对复合梁的抗折强度、能量吸收值、等效抗弯拉强度进行了计算。结果表明,聚丙烯纤维与凿毛处理均能提高复合切口梁的弯曲性能,聚丙烯纤维的掺加提高了复合梁的抗折强度,每当聚丙烯纤维掺量的增加0.45时,f_(eq)1、f_(eq)2大约增加0.035MPa,混凝土的能量吸收值也增加8%左右;凿毛处理大幅度提升了等效弯拉强度,等效弯拉强度f_(eq)1、f_(eq)2分别提升了0.05 MPa、0.03 MPa,凿毛处理对f_(eq)1的提升效果比f_(eq)2更明显,使得复合梁的能量吸收值平均提升了20%。

After the old asphalt pavement has been treated by milling, the concrete overlay is mostly made of fiber concrete, in order to study the effect of polypropylene fiber andchisel handle on the bending toughness of composite notched beams, the three point loading test of high performance concrete-asphalt concrete （AC-13） composite notch beam with polypropylene fiber was carried out, the relation curves between load and deflection, CMOD were obtained, the flexural strength, energy absorption value and equivalent flexural tensile strength of composite beams were calculated. The results show that the polypropylene fiber and chisel handle can improve the bending performance of composite beam. Polypropylene fiber improves the flexural strength of composite beam. When the amount of polypropylene fiber increases 0.45,the content of/叫 1 an d /叫 2 increases about 0.035 MPa, and the energy absorption of concrete increases by about 8% . Chisel handle greatly improved the equivalent flexural strength, the equivalent flexural strength of feq 1 and feq 2 increase by 0. 05 MPa, 0. 03 MPa, respectively. The improvement effect of chisel handle on feq 1 is more obvious than that of /eq 2 ,so the energy absorption value of the composite beam increases by 20% on average.