Polymer/Carbon Fiber Co-modification: Dynamic Compressive Mechanical Properties of Carbon Fiber Modified Polymer Reinforced Concrete

To explore the dynamic compressive mechanical properties of carbon fiber modified polymer reinforced concrete (CFMPRC), the 100 mm diameter SHPB (Split Hopkinson Pressure Bar) test system was used to carry out impact compression tests of CFMPRC with different carbon fiber volume content (0.1%, 0.2%, 0.3% and 0.4%). The dynamic stress-strain curves and fracture morphology of CFMPRC under different strain rates (37.7 s^-1 to 132.2 s^-1) were obtained, and the effects of strain rate and carbon fiber content on dynamic compressive strength, deformation and toughness of CFMPRC were analyzed. The results show that the dynamic compressive strength, deformation and toughness of CFMPRC have obvious strain rate strengthening effect and carbon fiber strengthening effect. The dynamic compressive strength, dynamic increase factor (DIF), dynamic peak strain and impact toughness of CFMPRC increase with strain rate gradually. The dynamic compressive mechanical properties of polymer reinforced concrete are improved by adding carbon fiber, and the optimal carbon fiber content is 0.2%. When carbon fiber content is 0.2%, the strain rate sensitivity of CFMPRC is the strongest, and the increase of strength is the maximum. Carbon fiber can bridge the internal cracks of concrete, and shows the co-modification effect with polymer. Polymer can enhance the carbon fiber/concrete matrix interface, which makes carbon fiber exert its effect more effectively.