Application of Fly Ash for High Strength Concrete

The utilization of waste material like fly ash is the need of time. Hence, application of fly ash for improving the properties of concrete is studied. It is found that by introducing fly ash in concrete, properties of concrete are altered. It will be helpful for sustainable development of concrete. Concrete containing very high volume of fly ash is usually called high volume fly ash concrete (HVFAC). The HVFAC is one specific type of fly ash concrete with higher fly ash contents, lower water/cement ratio (W/C), and lower cement contents. This is to take full advantage of the increased workability and strength provided by fly ash and the low W/C, and to produce a more environment friendly concrete by reducing its cement content. Volume change is one of the most detrimental properties of concrete, which affects the long-term performance of concrete. To the practical engineer, the aspect of volume change in concrete is important from the point of view that it causes unsightly cracks in concrete. One of the most objectionable defects in concrete is the presence of cracks, particularly in floors and pavements. Shrinkage is one of the main factors responsible for fine cracks in concrete.