The Effect of Hot and Cold Weather on the Performance of High Strength Fly Ash Concrete

The effect of the temperature in which high strength fly ash concrete is mixed, placed and cured is examined in this thesis. An experimental study was performed to determine the compressive strength development and modulus of elasticity of concrete mixes, with and without fly ash (Class C and Class F), when subjected to different hot and cold weather mixing and curing regimes. The structural behavior of high strength fly ash concrete members is affected by the large variability in curing conditions. Considering that concrete is poured in many different climates with contrasting temperature regimes, it is important to study the influence these factors have on the concrete material properties. The ACI Committee 305 Hot Weather Concreting Report and the ACI Committee 306 Cold Weather Concreting study suggest several guidelines for these situations. Despite these suggestions, several projects have experienced damage due to inadequate compliance with these codes. It also should be noted that these codes do not specifically discuss the effect temperature has on the properties of high strength fly ash concrete. Information must be gathered to study the effect temperature has during mixing, placing, and curing on the development of high strength fly ash concrete.