A lightweight structural concrete is composed of coarse structural aggregate sized between ¼″ to ½″ occupying 15% to 25% of total concrete volume, large non-structural lightweight aggregate such as expanded polystyrene bead of a particular size distribution and volume amount, small size non-structural lightweight aggregate or entrained air cells of another specific size distribution and volume amount, and a dense cementitious composition comprising cement binder, pozzolan, and fine structural filler no larger than concrete sand ASTM C33.