The effect of exposed aggregate concrete gradation on the texture characteristics and durability

Abstract

To ensure a lower tire/road noise level and proper friction, exposed aggregate concrete (EAC) is widely used for the construction of major highways in Europe. Even though EAC is commonly used, the number of publications about the effect of the EAC composition on the texture characteristics and durability is lacking. Moreover, there are no publications about EAC mixtures for pedestrian sidewalks. The objective of this article is to develop a mixture gradation that will lead to better pavement surface characteristics and durability of EAC used for the wearing layer of highways and pedestrian sidewalks. Variations in the maximum coarse aggregate size and proportions were used to develop EAC mixtures. The experimental research results showed that increasing the amount of coarse aggregates improves the skid resistance, resistance to polishing, exposed aggregate peak number, and compressive strength but impairs the mean profile depth (MPD) and mean texture depth (MTD). Based on the evaluation of the experimental data collected in this study, all EAC mixtures with a maximum aggregate size of 8 mm (EAC 8) achieved higher compressive strength values than EAC mixtures with a maximum aggregate size of 5 mm (EAC 5). However, EAC 8 and EAC 5 showed similar values of flexural strength, splitting strength, skid resistance and resistance to polishing. The analytic hierarchy process (AHP) was developed and applied to prioritize all tested EAC alternatives considering the most important criteria. The EAC 5 mixture with 80% coarse aggregates fr. 2–5 mm (EAC 5_3) was selected as the most rational alternative for the wearing layer of pedestrian sidewalks, while the EAC mixture contained 70% coarse aggregate fr. 5–8 mm (EAC 8_1) was selected for the wearing layer of highways.