Effects of polypropylene fibers and aggregate contents on the impact performance of coral aggregate concrete

The paper aims to study the effect of polypropylene (PP) fibers and aggregate contents on the impact compression mechanical performance of coral aggregate concrete (CASC). 5 PP fiber contents (0 kg/m3, 1 kg/m3, 2 kg/m3 3 kg/m3, 4 kg/m3), 3 natural gravel replacement ratios (0 %, 40 %,70 %), and 3 impact pressures (0.10 MPa, 0.12 MPa, 0.14 MPa) were designed for the split Hopkinson pressure bar (SHPB) test herein. The PP fiber contents and gravel replacement ratios effects on the impact compressive properties of CASC were assessed in term of the stressstrain curve, the strain rate effects and the toughness. The results showed that the dynamic compressive strength enhanced obviously with the increasing PP fiber contents and gravel replacement ratio, while the excessive fiber can degrade its properties instead. There exists the apparent strain rate effect of dynamic compressive strength and dynamic increase factor. The addition of PP fiber and the gravel can also improve the toughness of CASC and weaken the strain rate sensitivity. Eventually, the dynamic constitutive model based on ZWT constitutive model was established by considering the material damage, which can excellently forecast the dynamic stress-strain curve of CASC and the dynamic mechanical properties.

Automated summary

This study aims to investigate the impact of polypropylene (PP) fibers and aggregate contents on the mechanical performance of coral aggregate concrete (CASC). The results revealed that increasing the PP fiber contents and gravel replacement ratio significantly improved the dynamic compressive strength and toughness of CASC, while excessive fiber can have a detrimental effect. The study also developed a dynamic constitutive model that accurately predicted the stress-strain curve and mechanical properties of CASC.