Experimental Investigation of Mix Proportions Effects on Roller-Compacted Concrete Properties Using Response Surface Methodology

This research investigated how cement content, the water to cement (W/C) ratio, and the sand to aggregate (S/A) ratio may affect Roller-Compacted Concrete (RCC) mechanical properties. Results were obtained through experimental tests and response surface methodology (RSM) analysis. Two cement content, three W/C ratios, and three S/A ratios were implemented, and their effects on Vebe time as consistency parameter, modulus of elasticity, and compressive, flexural, and tensile strengths were evaluated. The RSM model conformed with the analytical trend of results indicating that this method can be used as a powerful tool for analyzing the properties of RCC. It was found that the most efficient parameter affecting consistency of RCC was W/C ratio. The cement content and W/C ratio had an inverse relationship with the Vebe time, while the S/A ratio influences the Vebe time directly. The RSM analysis revealed that the cement content had the greatest impact on compressive strength in comparison to W/C and S/A ratio. In contrast to normal concrete, in RCC, the compressive strength increased when the W/C ratio increased up to 0.4 due to greater compactability. Results indicated that the modulus of elasticity was a function of coarse aggregate content. The flexural strength was governed by cement content and the first cracking strength of paste. However, in the splitting test, it was the S/A ratio had the maximum effect.

Automated summary

This research examined the impact of cement content, water-cement ratio, and sand-aggregate ratio on the mechanical properties of Roller-Compacted Concrete (RCC). Experimental tests and response surface methodology (RSM) analysis were conducted to obtain results. The RSM model demonstrated that it can effectively analyze RCC properties. It was found that the water-cement ratio was the most significant factor affecting consistency, while the cement content had the greatest influence on compressive strength.