Effect of Fly Ash on Strength of Pavement Quality Concrete

Abstract

Now-a-days with the growing industries large amount of waste products are produced. Disposal of these waste materials are required as they cause harm to human and other life. For its disposal large area is covered. As the production of waste is increasing day by day we need to find a substitute to overcome this problem. Fly ash is a waste product produced due to burning of coal in power generating plants. Concrete consists of cement, sand, fine and coarse aggregate. Production of cement emits large quantity of green house gases. Due to increase in construction work, demand for cement will also increase. So to avoid production of green house gases and to produce environment friendly concrete, cement is replaced with certain percentage of fly ash. Replacement of cement with certain percentage of fly ash is to improve the strength of pavement concrete. The fly ash used in this study is from Rourkela Steel Plant (RSP), Rourkela, Odisha and is of Class F. In the experimental study the replacement of OPC (Ordinary Portland Cement) with fly ash is done and to get the desired workability and strength. Polymer based superplasticizer is used for all grades of concrete. The compressive and flexural strength of PQC (Pavement Quality Concrete) with different percentage of fly ash has been studied for 3, 14 and 28 days. From the experimental results it has been noted that without superplasticizer the compressive strength of Pavement Concrete is less for both 7days and 28 days. With the use of superplasticizer the desired compressive strength is achieved. But in case of flexural strength even without superplasticizer concrete attains the required strength and with superplasticizer the flexural strength of PQC achieve higher strength.