Evaluation of the Beneficial Use of Recycled Concrete Aggregates at the MnROAD Test Cells

AUTHORS: Izevbekhai, B.; and Aili, M.

ABSTRACT: Sustainability is increasingly a critical issue in transportation, as activities continue to significantly impact the environment and our ability to maintain a healthy and prosperous society without jeopardizing the ability of future generation to do the same. Consequently, there is a growing recognition of the need for sustainable practices in infrastructure systems reflecting in current corporate policies and government regulations. Paucity of naturally occurring aggregates and blasted rocks at or near construction projects are ramified in two factors. First practitioners experience shortage of naturally occurring aggregates and blasted rocks due to their depletion at sources where needed. Secondly, the haulage option implies huge cost of transporting naturally occurring aggregates and blasted rocks from distant sources. The increased usage of recycled aggregates in concrete thus triggered a series of studies including a 2010 test cell and two-lift concrete test cell where the lower lift was made of recycled concrete aggregates and a 2013 imitative that constructed a concrete test cell containing recycled aggregates as 75% of the total coarse aggregate content. After monitoring these cells and a control cell over time their performances were compared to those of control cells using age-normalized Load Transfer Efficiency and International Roughness Indices. Rebound Hammer and Petrographic Analysis facilitated evaluation of the 2-lift interface as well as relative conditions of each lift. Petrographic analysis validated internal curing in the lower lift.