Performance assessment and footprint analysis of recycled fine aggregate self curing concrete

Abstract

In the present era, construction sector mainly focuses on the sustainable newlineconstruction materials so that it can reduce the impacts it creates on the newlineenvironment. Over exploitation of natural resources and producing a large amount newlineof waste every year can significantly deteriorate the quality of well-being of living newlineorganisms. This research work is aimed at developing a concrete with reduced newlineusage of water and sand, with higher utilisation of recycled concrete waste. newlineSelf-curing concrete is a special type of concrete in which no water is newlinerequired externally for curing process and certain ingredients used in the newlineproduction of this concrete can themselves act as an internal reservoir of water. newlineHere, the curing process takes place internally. Recycled Fine Aggregates (RFA) newlineare usually processed from the concrete waste of construction and demolition newlinewaste. These RFA are found to have higher water absorption behaviour than newlinenatural fine aggregates due to the presence of adhered mortar of parent concrete. newlineThis behaviour has been utilised positively in the production of self-curing newline-Curing(RFA- RFA, water retainingadmixture Polyethylene Glycol 400 (PEG 400) has also been utilised in the production of this concrete in order to achieve the required internal curing. This research work comprises of three phases. The first phase focused on newlinethe strength optimisation of RFA Concrete using Taguchi design. The parameters newlineconsidered for this study were the replacement proportions of RFA to that of newlinenatural fine aggregates (0%, 10%, 20%, 30%, 40% and 50%), OPC and PPC as newlinethe two variants of cement and two types of curing process as self-cured and newlinenormal moist-cured techniques. Experimental investigations were conducted on newlinecubes, cylinders and prisms to examine the compressive strength, split tensile newlinestrength and flexural strength respectively to study the performance of concrete newlineunder different parameters considered.Based on the results obtained from the experimental investigations,optimisation studies were conducted on RFA concrete using Taguchi Design in newlineMinitab software. Optimisation studies indicated the optimum replacement newlineproportion of RFA as 40% for both compressive strength and split tensile newlinestrength whereas 30% RFA replacement proportion as optimum for flexural newlinestrength. Optimum type of cement was found to be OPC and self-curing process newlinewas found to produce optimum results with respect to all the three strength newlinecharacteristics.Second phase of research work was conducted to study the sustainable newlineperformance of RFA-SC Concrete based on durability studies, microstructural newlinestudies, carbon footprint studies and water footprint studies. Durability studies newlineincluded acid resistance test, chloride resistance test, sulphate resistance test, newlinewater absorption test conducted on RFA-SC concrete specimens for the six newlinereplacement proportions of RFA with OPC as the binder. newline newline