Impact resistance of nano-modified recycled aggregates concrete.

Reusing waste resources like recycled concrete aggregates (RCA) can benefit both the environment and the economy. Using RCA in concrete mix can help save natural resources and minimize CO2 emissions. However, up to date, most studies have revealed poor performance and strength under external stresses. Currently, researchers have recommended using nanomaterials to improve recycled aggregates concrete (RAC) mixes. Despite reasonable published findings, no study on MWCNTS has been accomplished. The goal of this study is to assess the fresh and hardened properties of RAC treated with various MWCNTS concentrations and RCA replacements. To achieve this, 60 concrete mixes were made with RCA at of 0, 25, 50, 75, and 100% and MWCNTS at 0.05, 0.15, and 0.25%. Workability and impact performance were discussed in this paper. The repeated drop blows weight impact (RDBWI) method described by ACI 544-2R was utilized to assess impact resistance at 28 days. The results showed that adding MWCNTS reduced the RAC slump by 60.8 to 73.5% but significantly increased the impact resistance by 426 to 679%; 459 to 490% at two stages, namely the initial crack and collapse stages, respectively compared to conventional mixes. Also, 0.1% MWCNTS was found to be optimal for both stages. The findings will aid in the development of effective strategies to promote the use of nanomaterials in RCA applications for both sustainability and performance. [ABSTRACT FROM AUTHOR]