Title : MECHANICAL PROPERTIES OF SELF COMPACTED RECYCLED CONCRETE AGGREGATES USING TWO STAGE MIXING APPROACH
Authors : Puja Rajhans, Sarat Kumar Panda, Sanket Nayak
Publication : 8 - 10, October 2015
Volume : 1
Pages :
Price : 250
Abstract : This paper addresses the methods of improvement of mechanical properties of self compacting concrete (SCC) with the use of coarse recycled concrete aggregate (RCA) obtained from construction and demolition (C&D) waste. Two stage mixing approach (TSMA) is employed, in which water is divided into two parts. All the other quantities of ingredients are added subsequently. Initially, fine and coarse aggregates were mixed for 60 secs, then half water and half SP were added in first stage and mixed for another 60 secs. After that total cementitious materials were added and mixed for another 30 secs. Finally, the remaining half of the water and SP were added in second stage and mixed for 120 secs. as per recommended procedure of mix design of SCC in the literature. In TSMA, during the first stage of mixing, a thin layer of cement slurry was formed on the surface of RCA which fills up the old cracks and voids and thus stronger interfacial transition zone (ITZ) is developed around the aggregate, resulting improved strength of concrete. Experimental results show that 100% replacement of RCA marginally affects the mechanical properties in two stage mixing approach (TSMA). However, TSMA significantly improves all the mechanical properties as compared to normal mixing approach (NMA).