EFFECT OF MINERAL ADMIXTURES ON THE FRESH PROPERTIES OF SELF COMPACTING CONCRETE PRODUCED WITH RECYCLED AGGREGATE

Senthamilselvi R, Revathi P

Abstract: The rising demand and decrease in supply of aggregates for the production of concrete result in the need to identify new sources of aggregates. On the other hand, majority of the countries are facing the problem of construction and demolition (C&D) wastes disposing. In view of this aspect, there has been a growing priority on the utilization of C & D waste and its by-products in construction activities. Self compacting concrete (SCC) having enormous advantages compared with the vibrated concrete which can be placed easily in congested reinforcements. Industrial by products/waste materials such as fly ash, Silica fume and granulated blast furnace slag are generally used as mineral admixtures in SCC. The mineral admixtures can improve particle packing, improve the quality of recycled aggregate (RA) and decrease the permeability of concrete. This investigation is an attempt to examine the influence of different mineral admixtures such as Silica fume and Ground Granulated Blast Furnace Slag (GGBS) on the fresh properties of SCC produced with recycled aggregate (RA). Recycled concrete aggregate is used as coarse aggregate in the production of SCC, with varying percentage replacements of natural coarse aggregate (NA) from 0% to 100% with increment of 50%. Cement is partially replaced with Silica fume (5 %, 10% & 15%) and GGBS (20%, 40% & 60%) in various proportions. Fresh Properties of all the mixes are assessed by the following tests namely slump flow, T500, J ring, V funnel, T5mins and L-box. The test result shows that the mineral admixtures extensively increase the workability with an increase in the percentages of RA. The result also shows that all SCC mixtures satisfy the EFNARC standard values of fresh properties. From this it is concluded that recycled aggregate can be effectively used in the production of SCC

Keywords: Self Compacting Concrete Recycled Aggregate, Fresh Property, Mineral Admixtures.

DOI: https://doi.org/10.15623/ijret.2016.0532029