玄武岩纤维贫混凝土力学性能研究

Study on Mechanical Properties of Basalt Fiber Lean Concrete

从贫混凝土基层的复合式路面的使用状况来看,反射裂缝的问题比较突出.玄武岩纤维贫混凝土是一种能有效减弱或者避免贫混凝土产生反射裂缝的新型混合料.通过一系列室内试验,对玄武岩纤维贫混凝土的抗压强度、抗弯拉强度、抗冲击能力以及静力抗压弹性模量等力学性能进行了系统研究.得出玄武岩纤维最佳掺量为混合料总质量的2.0‰,最佳掺量范围为3～6 kg/m3.掺入玄武岩纤维后,能大幅提高贫混凝土的早期抗压、抗弯拉强度,且28 d龄期的纤维贫混凝抗压强度和抗弯拉强度也较一般贫混凝土提高了20%以上;可使贫混凝土具有良好的抗冲击性能,较普通贫混凝土提高了近1/3倍;可提高贫混凝土材料的静力抗压弹性模量,但提升幅度不大.

The problem of reflection crack is outstanding from the aspect of usage situation of lean concrete base composite pavement. The basalt fiber lean concrete is a new kind of mixture which can effectively weaken or avoid reflection cracking in the lean concrete. By a series of indoor tests, mechanical properties of the basalt fiber lean concrete such as compressive strength, bending tensile strength, impact resistance and static compressive modulus of elasticity were studied. The results were obtained as follows： the opti- mum dosage of basalt fiber was 2.0%o of the total weight, and the dosage range was 3 - 6 kg/m3 ; mixing basalt fiber could greatly im- prove the compressive and bending tensile strength of the lean concrete at early age, and then the compressive strength and bending strength of fiber lean concrete at the age of 28 days were improved up to more than 20% of normal lean concrete; the lean concrete had a good impact resistance performance after mixing basalt fiber, which increased nearly a third times than normal lean concrete; the stat- ic compressive modulus of elasticity was improved, but the increment was not too much.