A systematic mix design method for high strength concrete

Abstract

In this presentation, a systematic and easy to use mix design method for high strength concrete (HSC) is proposed. It is based on the Design of Normal Concrete Mixes!]O) published by the Department of Environment (D.OE) of United Kingdom. Experimental results showed that the concrete proportioned by the proposed method can achieve compressive strength of up to 120MPa at the age of 28 days. It was found and suggested in the proposed method that the lowest free-water to cement ratio should be limited to 0.22 in terms of practicality and economy. Furthermore, the relationship between the 28-day compressive strength and the free-water to cement ratio determined from the experimental result was very similar to the extrapolation of that of the D.OE manual. It shows that the modification of the D.OE Method is a possible means to design high strength concrete mixture. A research programme is now being undertaken to develop a systematic mix design method for HSC and very high strength concrete (VHSC) incorporating local pozzolanic materials such as pulverised fuel ash and microsilica.