Effects of pore water saturation on the mechanical properties of fly ash concrete

This paper investigates the effects of pore water saturation on the ultrasonic pulse velocity, rebound value, compressive strength, and elastic modulus of fly ash concrete. Fly ash concrete was placed in an artificial climate chamber to achieve different degrees of pore water saturation. Effects of the level of fly ash replacement and the degree of pore water saturation were examined on the concrete rebound value, ultrasonic pulse velocity, compressive strength and elastic modulus. The results showed that the influence of fly ash replacement on rebound values, ultrasonic velocity and elastic modulus was basically the same as on compressive strength. For the range of 0-45% for the level of fly ash replacement, the rebound value, the ultrasonic velocity, the elastic modulus and the compressive strength all reached their maximum value corresponding to the fly ash replacement level of 15%. As the degree of pore water saturation increased, the rebound value of fly ash concrete was increased first and then decreased, the compressive strength was decreased, but the ultrasonic velocity and the elastic modulus were increased.