Durability of concrete containing aggregate produced from recycled concrete affected by alkali-silica reaction
thesisposted on 08.06.2021, 09:45 authored by Chris Christidis
Minimal information is available on the durability of concrete containing demolished concrete as an aggregate. The purpose of this study was to: investigate and control the reactivity of recycled concrete aggregate (RCA) produced from concrete that was suffering from alkali silica reaction (ASR); and investigate other durability issues of concrete containing RCA with emphasis on salt scaling and freezing & thawing. It was deduced that the RCA produced from ASR-affected concrete caused expansion when used in new concrete as an aggregate. This high reactivity of the tested RCA was attributable to its relatively high alkalis and calcium contents. Furthermore, a greater amount of SCM was required to reduce expansion compared to concrete containing raw natural reactive aggregate. In terms of freezing and thawing and salt scaling, concrete containing coarse RCA at a 100% replacement level of coarse aggregate showed lower durability compared to concrete made with natural coarse aggregate.