【作者】 黄俊； 姜弘道；

【Author】 HUANG Jun, JIANG Hong-dao (College of Civil Engineering, Hohai Univ., Nanjing 210098, China)

【机构】 河海大学土木工程学院；

【摘要】 对48根282mm×100mm×30mm的板状试件进行了直接拉伸试验,采用两端外夹式的拉伸试验方法,利用合理的颗粒级配,获得了较密实的高性能砂浆。在砂浆中分别掺入不同体积含量的高强高弹模PVA纤维时,进行了纤维对砂浆的抗拉强度、抗拉应变、断裂能的增强效果的研究,对砂浆中仅加入粗骨料或PVA纤维以及同时加入粗骨料和PVA纤维时复合材料的拉伸力学性能进行了分析,完整地获得了各类试件的应力-应变全曲线。分别对高强、高弹模PVA纤维以及粗骨料对砂浆的增强机理进行了探讨,分析了在砂浆中加入粗骨料时裂纹扩展直接穿过粗骨料的破坏模式,同时对相同体积含量但具有不同纤维长度的两种纤维分别对砂浆的增强增韧效果进行了对比研究。试验结果显示:砂浆中纤维体积含量为4％时可获得最高的抗拉强度,纤维过短会降低复合材料的抗拉强度。更多还原

【Abstract】 By the uniaxial tensile tests on 48 plain specimens(282mm×100mm×30 mm) with steel plates connecting manner, a high performance mortar is acquired with a good grain gradation. The properties about tensile strength、tensile strain and fracture energy of mortar mixed with high strength、high elastic modulus PVA fiber by different volume fraction are studied. The mechanics properties of composites are analysised when the coarse aggregates or the PVA fibers or the coarse aggregates and the PVA fibers are added into the mortar. The stress-strain whole curves of different specimens are obtained. It is discussed for the strengthening mechanism about mortar added with PVA fibers. When the mortar is mixed with coarse aggregate, cracks will penetrate into the coarse aggregate. The strengthening effects of different fiber length with the same volume fraction to mortar are compared. The result displays: composites have the highest tensile strength with the 4% volume fraction PVA fiber ,very short fibers will decrease the tensile strength of composites.更多还原