橡胶粉掺量和细度对路用橡胶混凝土物理力学性能影响分析

为研究橡胶粉掺量和细度对路用橡胶混凝土物理力学性能的影响规律,以3种橡胶粉掺量和4种橡胶粉细度为变化参数,对橡胶混凝土和普通混凝土进行抗弯拉强度和立方体抗压强度试验,并得出橡胶混凝土脆性系数。试验结果表明:橡胶混凝土脆性较小,具有良好的变形能力;橡胶粉掺量对混凝土各强度指标的影响程度高于细度对其的影响;橡胶粉掺量10%和20%的橡胶混凝土的抗弯拉强度和立方体抗压强度均随橡胶粉掺量的增加而减小,随橡胶粉细度的增大而增大;橡胶混凝土脆性系数随着橡胶粉掺量的增加而不断减小;橡胶粉掺量30%、细度为177 μm的橡胶混凝土性能指标的离散性较大,建议实际工程中采用掺量≤20%,细度≤250 μm的橡胶粉。研究成果可为橡胶混凝土在道路工程的应用提供参考。

Influence of Content and Fineness of Rubber Powder on Physical and Mechanical Properties of Road Rubber Concrete

The aim of this study is to probe into the influence of dosage and fineness of rubber powder on the physical and mechanical properties of road rubber concrete. We performed flexural tensile strength and cubic compressive strength tests to obtain the brittleness coefficient of rubber concrete with the dosage and fineness of rubber powder as variables (three different dosages and four different fineness). Results revealed small coefficient of brittleness and good deformation performance of rubber concrete. The influence of rubber powder dosage is higher than that of fineness. The flexural tensile strength and cubic compressive strength of rubber concrete with a dosage of 10%-20% decreased with the increasing of the content of rubber powder, while increased with the increasing of the fineness of rubber powder. The brittleness coefficient of rubber concrete reduced continuously with the increasing of rubber powder content; but increased along with the increasing of the rubber fineness. The performance indices of rubber concrete with a rubber content of 30% and fineness of 177 μm are highly discrete. Therefore we recommend a dosage ≤20% and fineness ≤ 250 μm of rubber powder in practical engineering.