Center for By-Products Utilization MECHANICAL PROPERTIES OF CONCRETE INFLUENCED BY INCLUSION OF FLY ASH AND TEMPERATURE

This research was carried out to evaluate performance of concrete produced, placed and cured under weather conditions normally followed in this country as well as several other countries. Mechanical properties of concrete containing low-calcium fly ash were determined under simulated hot and dry weather conditions. Compressive strength, tensile strength, and secant modulus of elasticity were measured. A concrete designed to have 28-day compressive strength of 2500 psi (17 MPa) was used in this investigation. Mechanical properties were measured at three levels of temperature 73, 95 and 120'F (23, 35 and 49*C) and four levels of cement replacement by Class F fly ash (0, 10, 20 and 30%) on an equal weight basis. Results show that for hot weather the optimum quantity of this low-calcium fly ash varied between 10-20% by weight of cement used with respect to compressive strength, tensile strength, and secant modulus depending upon test temperature and age.