Performance evaluation of pond ash aggregate modified concrete reinforced with polymeric fibres

Abstract

Natural aggregates used in concrete are obtained from naturally occurring rocks. Digging a quarry destroys habitats of wildlife. The usage of natural aggregates has become serious issue in this developing infrastructure era. Utilization of Pond ash in concrete will be a viable solution. Utilization of pond ash in manufacturing artificial aggregate overcomes its disposal issues. Pond ash is a by-product of Thermal power plant. Many studies were made and shown that utilization of such material gives better performance to the efficiency of concrete. Attempt has been made to utilise pond ash in manufacturing artificial aggregates. In addition to the usage of artificial aggregates, these aggregates are reinforced with the help of polymeric fibres. Polymeric fibres addition helps in increasing the bond between the concrete matrix. Any types of mechanical failure in concrete will affect the concrete matrix only and not the aggregate hence strengthening the matrix is also to be considered. Artificial aggregate of nominal size 20 mm is manufactured using pond ash and cement which is cured for 7 days. Cement to pond ash ratio 14:86 is used in manufacturing of pond ash aggregates. Aggregates are manufactured using Pelletization process. Disc pelletizer are used for the manufacturing of Artificial aggregate and angle of inclination used is 35o to 55o with rotating speed of 35 to 55 rpm. Then packing density method of concrete mix design for M20 is performed. Artificial aggregates made of pond ash are replaced for coarse aggregates in various proportions (0%, 10%, 20%, 30%, 40%, and 50%). Polypropylene fibre is added in different volume fraction (0%, 0.1%, 0.2%, 0.3% and 0.4%) to the M20 concrete mix. Mechanical properties have been studied and the values are then compared with conventional method of manufactured concrete.40% replacement of artificial aggregates made of pond ash was found to be optimum. Application of artificial aggregates enhances the mechanical properties of the concrete and also fibre addition improves the efficiency still better. Since fibres bridged the crack in concrete matrix, split tensile strength and flexural strength increases on increasing the dosage of polyproplylene fibres. Regression analysis is performed to arrive the relationship between compressive strength and flexural strength. Durability test is performed for the optimized mixes and the results were compared with control concrete. Since polypropylene fibre is non-polar in nature, it is least affected by acids and salts.40% pond ash and 0.4% polypropylene fibres records least value in the results obtained. Fibres resistance property to chemical attack improved the durability performance of these mixes. newline