Research on compressive strength of hybrid fiber reinforced concrete based on orthogonal design

The influence of steel fiber and polypropylene fiber mixed on compressive strength of high performance concrete (HPC) was studied. The steel fiber content (0.5%, 1.0%, 1.5%, 2.0%) (volume fraction, the same below), polypropylene fiber content (0.05%, 0.1%, 0.15%, 0.2%) and length (5mm, 6.5mm, 12mm, 18mm) were studied by L 16 (4 5 ) orthogonal test for 28d ages, the range analysis and variance analysis of the test results are carried out, and the prediction model of compressive strength of hybrid fiber reinforced concrete was established. The results show that: The significant influence factor of concrete compressive strength is the volume fraction of polypropylene fiber, while the length of polypropylene fiber and the volume fraction of steel fiber are not significant; the concrete compressive strength with polypropylene fiber shows negative hybrid effect; The prediction model of compressive strength of hybrid fiber reinforced concrete has high accuracy, and the average relative errors is 2.96%.