The effects of curing conditions on mortars using glass powder as cement replacement material

Abstract

The likelihood of adopting fine glass powder as a cement replacement material to protect the environment was examined by three types of experiments, including compressive strength test, sorptivity test and pundits test. To promote the comprehensiveness of this research, different curing conditions, namely air curing, 27°C water curing and 60°C water curing, were applied to the specimens. The investigated level of cement replacement were 0%, 20%, 40% and 60%. For the influences of level of cement replacement, all the properties of mortar were weakened by the increase of level of cement replacement, except the sorptivity; 40% cement replacement was the optimum level for the development of sorptivity. Larger glass particle size than cement was believed to be the reason of the above observation. In regard of the influences of curing conditions, firstly, water curing were more conducive to the performances of the specimens than air curing. Secondly, 60°C water curing promoted the early, day3 and day7, performances of the all specimens, but sometimes it was deleterious to the day60 performance. For example, the day60 compressive strength of the 60°C water cured specimens were lower than the 27°C water cured specimens, as a result of crossover effect; the development of pulse velocity in 60°C water curing were also limited by the same reason. Only the sorptivity of all samples in all age could be benefited by 60°C water curing. Apart from the influences of curing conditions and level of cement replacement, facts about correlations of pulse velocity and compressive strength were found. It is found that the slope of the linear correlation were very sensitive to the curing conditions and level of cement replacement.