High volume fly ash concrete: an innovative, cost effective, durable and eco-friendly material for cement concrete road

Roads are the life of any nation. Deterioration of Concrete Roads in India has been a matter of great concern for engineering fraternity throughout the world. In an effort to improve the performance of concrete, investigations have been made to develop durable, cost effective and eco friendly concrete composite using fly ash in a specified percentage (by weight) in place of cement. Study of behaviour of plain concrete and high volume fly ash concrete having fly-ash in high volume exposed to different aggressive environment (5% H2O sub 4 solution, 5% HCL solution, 10% (NH sub 4) sub 2 SO sub 4 solution, and 10% NaOH solution) for 28 days revealed that high volume fly ash concrete was more durable than ordinary Portland cement concrete (PCC). A specified percentage replacement of cement (by weight) by fly ash makes the concrete impervious and enhances the compressive strength and durability of concrete exposed to different aggressive environments. The strength of PCC exposed to aggressive medium reduced significantly. This reduction in strength was mainly due to expansive salt formation and weakening of bonds. The formation of expansive salt also resulted in cementitious properties and loss of weight. The investigations were carried out to establish correlation between durability and deterioration in properties for both undamaged concrete and concrete damaged by chemical attack. International and National scenario in the field of utilization of HVFC was presented. Economic aspects and environmental aspects were also discussed.