Packing density and surface finishing condition effects on the mechanical properties of various concrete pavements containing cement replacement admixtures

This paper presents an experimental research on the relation between methods of surface preparation and mechanical properties of concrete pavements containing cement replacement admixtures. It also tries to evaluate the effect of various weather conditions (cold, normal, and hot) on the mechanical properties. Nine types of mixtures including conventional concrete (CV) and self-consolidating concrete (SCC) with different packing density were prepared by adding silica fume, metakaolin, and low-activity-granulated blast furnace slag as a replacement of Portland cement. The results emphasized that the admixtures such as silica fume or metakaolin reduced plastic settlement and the risk of segregation potential in concrete pavement mixtures. However, using low-activity-granulated blast furnace slag in concrete pavement is not recommended due to a decline in the early age mechanical properties. The study of different methods of surface finishing with concrete mixture shows that the use of wooden troweling in the SCC reduces abrasion resistance and is, therefore, not recommended. The results of concrete mixture placement under various environmental conditions (including hot, normal, and cold weather) shows the SCC containing silica fume and metakaolin has a better performance compared to conventional concrete.