Influence of strain rate and water content on mechanical behavior of dam concrete

The influence of strain rate and water content on the mechanical behavior of dam concrete has been investigated. Sieved concrete specimens with water-binder ratio (w/b) 0.45 are subjected to four-point loading at strain rates of 10−6, 10−5, 10−4 and 10−3 s−1. All these tests were performed with a closed loop servo-controlled stiff testing machine. The tests provide stress–strain curves at the chosen strain rates. Strain rate sensitivity is measured with in terms of the stress–strain curves, the maximum stress (flexural strength), dynamic increase factor, elastic modulus and Poisson’s ratio. Strain rate sensitivities are compared for different water content (0%, 40%, 70% and 100%). The obtained results showed significant influences of strain rate and water content on materials behavior. Both flexural strength and elastic modulus increased with higher strain rates, while Poisson’s ratio remained unchanged. At same strain rate, increasing water content would increase elastic modulus, but lower the flexural strength.

► Concrete are subjected to four-point loading under different strain rates.
► Strength and elastic modulus increases with increasing strain rate.
► Dynamic increase factor is relative to strain rate and water content.
► Increasing water content will increase elastic modulus, but lower strength.
► Poisson’s ratio remains unchanged with strain rate and water content.