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

Abstract

Sustainability is increasingly a critical issue for the future of our planet, as activities especially in infrastructure development continue to significantly  impact the environment and our ability to maintain a healthy and prosperous society without jeopardizing the ability of  future generartion 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. Depletion metrics for aggregates for virgin aggregates debunk the conventional  assumption of infinite resources especially when logistic and material factors are introduced to  the analysis of regional  or local needs. There is consequently a paucity of the necessary local  virgin aggregates for infrastructure without expensive haulage or compromise of quality. 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 concete aggregates and a 2013 initative 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, age-normalized Load Transfer Efficiency and International Roughness Index were compared. Rebound Hammer as well as  well as Petrographic Analysis on the cares facilitated evaluation of the 2-lift interface as well as relative conditions of each lift.  Kullbach-Liebler Divergence analysis and t-test to 95% significance did not reject the null hypothesis of similarity in performance between the recycled concrete cells and the conventional cell performance.