Title: Comparison Among Different Mix-Design Procedures for RCA Concrete

Author(s): Diego Jesus De Souza, Leandro Sanchez, Faraz Ahimoghadam and Gholamreza Fathifazl

Publication: Symposium Paper

Volume: 334

Issue:

Appears on pages(s): 99-121

Keywords: recycled concrete aggregate, equivalent mortar volume method, modified equivalent mortar volume method, equivalent volume method

DOI: 10.14359/51720255

Date: 9/30/2019

Abstract:
Various studies on the use of recycled concrete aggregate (RCA) were developed in the past decades. Yet, very often direct replacement techniques are adopted to proportion RCA concrete, which leads to inferior performance of the recycled material when compared to conventional concrete. RCA is a multi-phase material comprised of original virgin aggregate and residual mortar (RM) and thus these distinct phases should be considered during the RCA mix-design process. The Equivalent Mortar Volume (EMV) mix-design method accounts for the RM to proportion RCA concrete. Although great results are normally achieved in the hardened state, EMV-designed mixtures may present important challenges in the fresh state. Modifications of the original EMV such as the modified-EMV and the Equivalent Volume method were recently proposed to tackle issues related to the fresh state and binder efficiency of recycled mixtures. This paper discusses the differences among the recent mix-design procedures developed to proportion RCA concrete.