Abstrakt

Flexural Strength of Concrete by Partial Replacement of Sand with Basic Oxygen Furnace Slag

Musawir Quadir

This research work evaluates the use of Basic oxygen furnace slag as a replacement for fine aggregates, in M-25 grade of concrete. The fine aggregates were partially replaced, by weight with Basic oxygen furnace slag. The prepared mixes were named as Mix-A, Mix-B, Mix-C and Mix-D. The mixes were prepared at 0%, 15%, 25% and 35% replacement levels respectively. All the mixes were fabricated at 0.46 water cement ratio. To study the behaviour and response of beam members, casted with above said composition, in flexure, the tests performed after 7 and 28 days on beam specimens and the composite mix prepared, were flexural strength test, density and slump test. IS standards were followed while conducting the above captioned tests. The obtained results were compared with those of controlled M-25 concrete mix. The investigated results found, vary according to proportions of supplementary constituents added to the M-25 concrete mix. The substitution of Basic oxygen furnace slag enhances the Flexural strength of M-25 concrete mix up to certain percentage. After adding 15% Basic Oxygen furnace slag in the mix, there is an increase of 17.67% strength after 7 days, and 17.26% increase after 28 days. The Flexural strength increases as compared to control mix as the percentage of Basic Oxygen furnace slag is increased. At 25% addition of Basic Oxygen furnace slag in the mix, there is an increase of 28.37% strength after 7 days, and 23.31% increase after 28 days. A decline in Flexural strength as compared to control mix was observed when the percentage of Basic Oxygen furnace slag was increased to 35%. A decrease by 3.16% was observed after 7 days, and 16.42% decrease after 28 days. Slump and unit weight of thus manufactured concrete also increases with the addition of Basic oxygen furnace slag to it. Thus Basic oxygen furnace slag can be successfully used in concrete, to improve flexural strength, slump values and weight of concrete as wells.