Influence analyses of mixing approaches on properties of conventional and interlocking-dense concrete

The main objective of this paper is to analysis the influence of mixing approaches on the properties of the conventional concrete (CC) and interlocking-dense concrete (IDC). Compared with the normal mixing approach (NMA), the two-stage mixing approaches (TSMA, including mortar mixed first (MMF), coarse aggregate wrapped with paste (CAWP), aggregate wrapped with cement (AWC)) were employed. The mixing homogeneity tests were conducted to evaluate the uniform of the fresh concrete with different mixing approaches. Moreover, compressive strength, flexible-tensile strength, flexible modulus and abrasion resistance tests were designed to evaluate the performance of the hardened concrete. Pearson correlation analysis and analysis of variance (ANOVA) was also involved to illustrate the correlation and differences between NMA and TSMA. The repercussion in the mixing homogeneity test shows that ΔG is a reasonable index to evaluate the uniformity of fresh concrete. This also reveals that the uniformity can be improved by TSMA for CC, while the MMF is the most effective approach to enhance the uniformity for IDC. The results help to find out that the most appropriate mixing approaches for CC and IDC are CAWP and MMF, respectively.