Effect of Dynamic Loading on Mechanical Properties of Concrete

Concrete structures have to bear dynamic loads in daily work, strength and deformation characteristics of concrete under dynamic loads differ from the characteristics under static loads, and this difference may become a key factor to restrict the structural safety under certain conditions. Using the MTS815 test system, the dynamic uniaxial compression tests of concrete specimens were conducted. The mechanical characteristic parameters of strength, elastic modulus, peak strain and the stress-strain curves at different loading rates of concrete specimens have been studied. The results reveal that concrete is a rate-sensitive material, as a small loading rate may lead to the rapid growth of strength; the variation rule of peak strain is not obvious with the increase of loading rate, thus the peak strain can be regarded as a fixed value in actual projects; the higher the loading rate is, the greater the concrete strength and the elastic modulus are; the elastic modulus increases essentially due to the improvement of structural stiffness; concrete specimens with the same mix proportion have similar stress-strain curves and the loading rate has little effect on the shape of the curve.