Modified Bolomey equation for strengths of lightweight concretes containing fly ash aggregates

The Bolomey equation has been used for relating the cement–water ratio to compressive strengths of concrete containing normal weight aggregate. This is basically a linear equation, not considering explicitly the parameters relating to coarse aggregates. Strengths of lightweight concretes containing fly ash aggregates (FAAs) are influenced both by cement–water ratio and the properties of the aggregates. It is generally very difficult explicitly to determine the properties of lightweight aggregates (such as FAAs). In view of this, a modified Bolomey equation, considering indirectly the presence of FAAs, is suggested in this paper, using the experimental data generated at the Structural Engineering Research Centre, Chennai. Applicability of this formula is checked with reference to the published data.