Investigation of the hydraulic characteristics and homogeneity of the microstructure of the air voids in the sustainable rigid pavement

Abstract

The present research investigates how incorporating waste concrete block aggregates (WCBA) in place of natural coarse (5–12 mm) aggregates (NCA) affect the characteristics of concrete pavement. The topography of the voids, water absorption, porosity, and hydraulic conductivity characteristics such as flexural and compressive strengths in addition to density were investigated. The consequences of replacement were looked at using four replacement percentages, 10, 30, 60, and 100% of the normal weight had been substituted with 0% functioning as the control value. Mix design of 1:1.41:2.52 (cement:fine aggregate:coarse aggregate) was used in the study with water to cement ratio of 0.43. As the replacement percentage of WCBA increased, water absorption, porosity, and hydraulic conductivity increased while density, compressive strength, and flexural strength decreased. The drop in values in comparison to control mixture were in the range of 10–30, 22–40, and 1–32% for density, compressive strength, and flexural strength, respectively. On the other hand, increase in values (16–33, 12–40, and 11–37%) have been identified for hydraulic conductivity, porosity, and water absorption, respectively. When designing rigid pavement, concrete with replacement percentages of WCBA 30% produces results that were acceptable. Porosity along with other hydraulic characteristics, such as hydraulic conductivity, are closely associated. There is an extremely significant correlation between porosity and all topological parameters. Finally, high level validation (R 2 > 0.9) and predictive models of hydraulic conductivity and porosity were established.

Keywords

• recycled
• aggregate
• concrete
• voids
• models
• topology
• hydraulic conductivity