A One Year Investigation of Self-Compacting Concrete With Recycled Asphalt Pavement

Abstract

Abstract This paper investigated the behavior of self-compacting concrete mixtures produced from high volume of supplementary cementitious materials incorporated with moderate and high percentages of recycled asphalt pavement as a partial replacement of coarse aggregate (CA). The mechanical properties and unrestrained shrinkage of 12 self-compacting concrete mixes through one-year timeframe are investigated. All mixes were proportioned to accomplish self-compacting concrete characteristics with constant water to cementitious materials ratio of 0.37. Three groups of mixtures were investigated while all groups consist of a control mixture without any cement replacement and three other mixtures made with various percentages of supplementary cementitious materials (SCMs), such as fly ash and ground granulated blast furnace slag. Mixtures in group I were made with 100 % natural coarse aggregate, whereas those in groups II and III, the coarse aggregates were partially replaced by 25 and 50 % recycled asphalt pavement, respectively. The fresh properties, the compressive and tensile strengths, and the unrestrained (free) shrinkage of all mixtures were investigated up to 365 days. The compressive strength was measured at 3, 14, 28, and 365 days, whereas the free shrinkage was periodically measured up to one year. Results show that self-compacting concrete (SCC) can be developed with up to 70 % of cement replaced by supplementary cementitious materials and up to 25 % of coarse aggregate replaced by recycled asphalt pavement, whereas up to the 25 % replacement, the proposed mixtures showed very comparable results to the conventional SCC mixtures. A linear regression analysis was also conducted to correlate the studied compressive strength to the mixture's ingredients and showed strong agreement with the experimental results.