Inclusive approach for mix proportioning of dry lean concrete based on the experimental study on the effect of cement and coarse aggregate content on strength and abrasion characteristics

This paper reported the effect of cement and coarse aggregate content on the mechanical and abrasion properties of dry lean concrete (DLC) and proposed design curves for its mix proportioning. DLC has a wide application as a sub-base layer for rigid pavement. 12 DLC mixes were prepared by varying cement content as 150, 180, 210 and 240 kg/m³ and by varying ratio of coarse aggregate-to-total aggregate (CA/TA) ratios as 0.50, 0.60 and 0.70. The strength results such as 7- and 28-day cube and 7-day cylinder compressive strength, 7-day splitting tensile strength and 7-day and 28-day flexural strength increased with increasing cement content and increasing ratio of coarse aggregate-to-total aggregate. The abrasion test showed that mixes with higher cement content and higher coarse aggregate-to-total aggregate ratio exhibited the highest abrasion resistance index. This study has proposed design curves for mix proportioning of DLC based on the correlations between 7- and 28-days cube compressive and flexural strengths for estimating cement, aggregate and water content. The proposed design curves were verified with experimental results and showed a reasonably good prediction.