Use of Waste Materials for Sustainable Development of Rigid Pavement

Earth's natural resources belong to everyone and must be maintained for future generations. Thus, waste management and consumption are researchers' main concerns. Using waste resources to build sustainably. It's growing increasingly popular due to its environmental and economic advantages. This paper uses waste materials to increase the sustainability in construction work with cement-based such as waste concrete as a normal aggregate replacement and ground-granulated blast-furnace slag (GGBFS) as supplementary cementitious materials (SCMs) to improve the sustainability in rigid pavements production, to decrease the use of raw materials, and to reduce the CO2 production in Portland cement (PC) factories. Cubic, cylindrical, and prismatic specimens were prepared in the laboratory with (0%, 10%, 20%, 30%, and 40%) by weight of aggregates waste concrete (WC) as replacements from the natural aggregates. The strength activity index (SAI) of the concrete specimens was in the acceptance strength zone with a slight reduction when compared with the conventional concrete strength. On the other hand, the hybridized effect of using the GGBFS as SCMs with various proportions of GGBFS/PC (0.8, 1.2, 1.6, 2), and WC at (40%, 30%, 20%, and 10%) respectively appeared that SAI was enhanced. Three manufactured specimens in each type of mixture were tested after 7 and 28 days of age curing. The findings from compressive strength, splitting, and flexural tests conducted on mixtures containing recycled aggregate indicate their suitability for use in rigid pavements for secondary roads. It was observed that as the proportion of recycled aggregate in the mixture increased, the strength of the concrete decreased. when ground granulated blast furnace slag (GGBFS) was added to the concrete mixtures, the results varied depending on the ratio of GGBFS present in the mixture. Among the different mixes tested, the mix designated as R30S1.2 was the highest strength load and it can be used for main roads. The results indicate that the use of recycled aggregates at a ratio of 30% and 55% GGBFS gave the best strength results and at the same time reduces the amount of cement and natural aggregates used, and this has an impact on the environment by reducing the presence of waste.