Can Concrete Containing High-Volume Recycled Concrete Aggregate Be Durable?

Abstract

This paper evaluates the effect of recycled concrete aggregate (RCA) on concrete durability. Six RCA types procured from different sources were employed at 30 to 100% replacement rates by volume of virgin coarse aggregate. One fine RCA was also investigated and was used for up to 40% replacement by volume of virgin sand. In total, 33 mixtures were proportioned with these aggregates in concrete made with a binary or a ternary binder system and a water-cementitious materials ratio (w/cm) of 0.37 to 0.45. The mixtures were investigated for frost durability, electrical resistivity, sorptivity, and abrasion resistance. Test results indicate that concrete made with up to 100% coarse RCA from an air-entrained source can exhibit proper frost durability. No significant reduction (limited to 3%) in frost durability factor was observed when the fine RCA volume was limited to 15% of total sand. Increase in mass loss due to deicing salt scaling was observed in concrete made with 50% of RCA with high (over 4%) deleterious materials content and high mass loss during soundness test. For a given w/cm and binder type, the use of 50% coarse RCA resulted in up to 32% reduction in electrical resistivity. The reduction in w/cm from 0.40 to 0.37 and the use of ternary binder containing 35% Class C fly ash and 15% slag proved to be effective in mitigating the potentially negative impact of RCA on sorptivity and abrasion resistance, compared to concrete made without any RCA with w/cm of 0.40 and binary cement with 25% fly ash.

Department(s)

Civil, Architectural and Environmental Engineering

Keywords and Phrases

Abrasion; Binary mixtures; Binders; C (programming language); Concrete mixtures; Concrete testing; Durability; Electric conductivity; Fly ash; Recycling; Slags; Sustainable development; Tribology; Wear resistance; Air-void systems; Cementitious materials; Concrete durability; Deleterious materials; Frost durability; Recycled concrete aggregates; Replacement rates; Scaling resistance; Concrete aggregates; Electrical resistivity; Sustainability

International Standard Serial Number (ISSN)

0889-325X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2018 American Concrete Institute (ACI), All rights reserved.

Publication Date

01 May 2018

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