THE EFFECT OF GROUND GRANULATED BLASTFURNACE SLAG ON THE STRENGTH DEVELOPMENT AND ADIABATIC TEMPERATURE RISE OF CONCRETE MIXES

摘要

The strength development of concretes containing ground granulated blastfurnace slag (GGBS) has been investigated under standard and adiabatic curing conditions. Concretes with cement replacement levels varying from 0 to 70%, and water/binder ratios from 0.25 to 0.80 have been investigated. For a given water/binder ratio, the 28-day strength is approximately the same, irrespective of the level of cement replacement. However, the early age strengths of GGBS concrete are lower than those of Portland cement concrete. The adiabatic temperature rises of concretes with target mean strength of 70N/mm~2 at 28 days and cement replacement levels of 0, 35, and 70% have been measured. Their strength development under adiabatic conditions has been determined and compared with the strength development under standard curing conditions. For higher cement replacement levels, the adiabatic temperature rise is slower and the peak temperature reached is lower. Concretes containing GGBS show a much greater improvement in early age strength than PC concrete, even though the adiabatic temperature rise is lower, with 2-day strengths as high as 21/2 times the standard cured strength.