No abstract

The use of different supplementary cementitious materials (SCMs) has attracted the interest of researchers for years. These materials have their advantages and dis-advantages. The optimal use of these SCMs in concrete may call for blending them together in concrete instead of using them individually. The blend may increase their quality as one disadvantages may be catered for by another one advantages. The present study focusses on investigating the effect of proportional combination of these SCMs on strength development. Three different South African SCMs (Ground granulated blast-furnace slag, Silica fume and Fly ash) were blended at different proportions and used as replacement of cement in concrete. Compressive strength test based on SANS 5860:2006 standard were adopted. The compressive test was performed on 16 different mixes at 7, 14, 28, 90 and 120 days curing periods. The water/cement ratio for all the mix was maintained at 0.5. The compressive strength results are desirable for each curing age at the 30% replacement of cement in which each SCM contributes 10% to the mix, greater strength value at curing age beyond 120 days compared to control sample was envisaged for this sample.

-In this paper, the embedded reinforcement in concrete are usually sheltered from corrosion by a thick oxide layer formed on their exteriors because of the highly alkalinity of the exposed environment of the adjoining concrete which thus affect both the strength and durability of the affected structures. In spite of this protective mechanism, corrosion of the reinforcement remains one of the biggest common durability challenges. On the other hand, this destructive phenomenon affects not only the durability but the strength of the affected structures. However, the use of cementitious blends which has generated huge research interest for many years has greatly increased due to environmental concern and awareness. The present study focusses on investigating the effect of quaternary combination of South African supplementary cementitious materials on the early strength development of the concrete with a view to encourage local usage of these power plant by-products and to encourage reduction of CO 2 emission during the cement production.