Abstract: 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.

Key words: rubber concrete, physical and mechanical properties, flexural tensile strength, cubic compressive strength, brittleness coefficient