Curing/Environment Effect on Pore Structure of Blended Cement Concrete

The overall aim of this paper is to investigate the effect on pore structure of concretes exposed to hot and dry environments and made with combinations of portland cement, silica fume, and slag. Five different concrete mixes were cast and tested to investigate the role of different periods of water curing on the porosity and pore structure characteristics when exposed to two different hot/dry environments. The first environment was an indoor laboratory (23°C + 2°C and 70% relative humidity + 10%) and the other was the real outdoor environment in Dubai, representing a typical hot climate. Pore structure was evaluated by means of mercury intrusion porosimetry. The results indicated that longer water durations of water curing reduced porosity and pore sizes significantly. The influence of water curing was maximum in the case of slag mixes cured in the outdoor environment. Hot climates are seen to have adverse effects on the pore structure characteristics, especially when no water curing is involved. The properties of slag concrete were seen to be a function of duration of water curing. The properties of slag concrete mixes exposed to hot/dry environments without any water curing were very poor.