Analysis and Assessment of Strength Development in Concrete Cubes Using Granulated Blast Furnace Slag as Marginal Material

The Iron and steel industries produce a huge quantity of granulated blast furnace slag (GBFS) as a byproduct, which is a non-biodegradable waste material, from which only a small percentage is used by cement industry to manufacture cement. In the present investigation granulated blast furnace slag from local industries has been utilized as marginal material to find its suitability as a fine aggregate in concrete making. Replacing all or some portion of natural sand with slag would lead to considerable environmental benefits. The strength development when granulated blast furnace slag replaces the conventional sand is found to be more significant at lower water-cement ratios compared to higher water-cement ratios. In this investigation it is also intended to study the strength development in concrete cubes by replacing natural sand with granulated blast furnace slag at different proportions, on the basis of the Abrams’ law. The sand is replaced by granulated blast furnace slag at proportions of 10%, 20% and 30% by weight, in order to ascertain the effects more clearly. In the present study it was observed that the bulk density is reduced with reduction in water-cement ratio, as a result the strength developed with age got reduced with decrease in water-cement ratio. Keeping the bulk density constant by use of additional quantity and increasing the compaction effort the strength is found to be increased with decreasing water-cement ratio i.e., it follows Abrams’ law. Abrams’ law can be generalized by normalization of strength values at S0.6. This generalized approach to predict strength has been confirmed by additional experimental data.