玻璃纤维再生混凝土力学性能研究和微观结构分析

Mechanical properties and microstructure analysis of GF recycled concrete

利用经PVA溶液浸泡的PVA改性再生骨料替代部分天然骨料,同时掺入不同长度、不同掺量的玻璃纤维制备再生混凝土,研究玻璃纤维再生骨料混凝土的两项基本力学性能。结果表明:经改性后的再生骨料基本达到天然骨料强度,在此基础上掺入玻璃纤维,再生混凝土抗压强度得到显著提升,掺量0.1%、纤维长度为6 mm时最为明显,养护28 d时达到40.8 MPa,比未掺纤维时增大了33.7%;掺量0.2%时试件的劈裂抗拉强度均明显提高,纤维掺量0.1%时劈裂抗拉强度随纤维长度的增大而增大,但总体低于掺量0%纤维对照组。电镜扫描(SEM)发现改性再生骨料与其他材料粘结较好,玻璃纤维均匀分散于试件中。

The PVA modified recycled aggregate soaked in PVA solution is used to replace some natural aggregates,and at the same time,different lengths and different amounts of glass fibers are mixed to prepare recycled concrete,and the two basic mechanical properties of glass fiber recycled aggregate concrete are studied.The results show that the modified recycled aggregate basically reaches the strength of natural aggregate.On this basis,glass fiber is added,and the compressive strength of recycled concrete is significantly improved,which is most obvious when the content is 0.1%and the fiber length is 6 mm.It reaches 40.8 MPa at 28 days of curing,which is 33.7%higher than that without fiber;the splitting tensile strength of the specimen is significantly increased when the content is 0.2%,and the splitting tensile strength increases with the increase of fiber length when the fiber content is 0.1%,but it is generally lower than 0 fiber control group.Electron microscope scanning(SEM)found that the modified recycled aggregate bonded well with other materials,and the glass fibers were evenly dispersed in the specimen.