Fresh and Hardened Properties of Ternary Blended Fast Setting Early Strength Fibre Reinforced Self Compacting Concrete

Abstract

Cement, used for engineering the concrete structures has become the most demanded construction material, the production of which consumes enormous quantity of raw materials and thereby emits approximately 7% of greenhouse gas emissions into the environment. Determinations are being made to use, as much quantity as possible, the supplementary cementitious materials (SCM), like ground granulated blast furnace slags (GGBFS), flyash (FA), metakaolin (MK), silica fume (SF), rice husk ash (RHA), etc., which are industrial by-products and hold pozzolanic properties, and are capable to be used as a part replacement of ordinary portland cement (OPC). The consumption of OPC has significantly increased all over the world due to construction of infrastructure facilities on massive scales. Also for the aged infrastructure, constructed decades before, necessities maintenance and repairs thereby further increase the demand of OPC and thus cause higher impact on the environment. Researches all over the world are trying experimentations in finding out suitable combinations of various proportions of potential materials like finer SCMs viz. FA, GGBFS etc. and ultrafine SCMs like SF, MK, RHA etc. which are being investigated along with different types of fibres to produce fibre reinforced self-compacting concrete for use in fast track constructions and repair works. In this study on ternary blended SCC and FSCC (fibre reinforced SCC), concrete mixes were established with OPC ranging from 64% to 74%, combinations of proportions of MK (as ultrafine SCM), as a part replacement of OPC, varying from 2.5%, 5%, 7.5% and 10%; Fly ash (as fine SCM) fixed at 25%, without fibre and with 1% of Alkali resistant (AR) fibre. The established concrete mixes were set a target to achieve maximum final setting time of 10 hours, 1 day compressive strength of 25 N/mm² and flexural strength of 2.5 N/mm² besides meeting SCC characteristics of slump flow of 550mm-650 mm (SF1), V Funnel flow 9-25 Seconds (V2 class) for use in fast track concrete construction and repair of infrastructure facilities.