Effectiveness of fly ash and cement for compressed stabilized earth block construction

•Suitability of CSEB stabilized with cement and fly ash is assessed in terms of strength and durability.•Inclusion of fly ash is effective in reducing the cement content significantly.•Optimum fly ash content is 15% for 5–7% cement content.•Fly ash is effective in reducing water absorption capacity.•Fly ash and cement stabilized CSEBs are more suitable compared to fired clay bricks from economic standpoint.