The effect of constituent materials on the time development of the compressive strength of high-strength concrete

The effect of the constituent materials of different types of high-strength concretes, and the other characteristics of concrete mix, on the development of compressive strength has been studied. The measured values of the compressive strengths of concretes made using different types of cement and types of aggregate, as well as w/c ratios (water/(Portland cement + addition) ratios) and amounts of silica fume, have been compared and analysed. This investigation was performed with the emphasis on the early stages of maturing of such concretes. The results of measurements of compressive strength are shown from the initiation of the hardening process up to an age of 360 days. In the case of concretes containing cement with a high specific surface area and a predominant amount of alite, as well as in the case of concretes containing no silica fume or only a small amount of it, compressive strength increased rapidly in the early stage of hardening, whereas later its rate of increase was, in the majority of cases, practically insignificant.