Use of recycled aggregate concrete in structural members: a review focused on Southeast Asia

• Published in: Journal of Asian architecture and building engineering pp. 1 - 24
• Main Authors: Neupane, Ram Prasad, Imjai, Thanongsak, Makul, Natt, Garcia, Reyes, Kim, Boksun, Chaudhary, Sandeep
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 20-10-2023
• Subjects: recycled concrete; recycled concrete aggregate; state of the art review; structural performance
• ISSN: 1346-7581; 1347-2852
• DOI: 10.1080/13467581.2023.2270029

This article presents a comprehensive review on the use of recycled concrete aggregate (RCA) and recycled aggregate concrete (RAC) in construction, with emphasis on structural applications and identification of challenges and opportunities of RCA/RAC materials in Southeast Asia. For the first time and as a first step towards potential standardization of RCA/RAC in Southeast Asia, the article critically examines the physical and mechanical performance of RCA and RAC in structural applications. Global aggregate demand is projected to surpass 50 billion tons by 2025, with major Asian countries accounting for 62% of consumption. At the same time, the global annual production of construction and demolition waste (C&DW) exceeds 3.57 billion tons, and Asia is responsible for 53% of this total. Recycling C&DW plays a crucial role in addressing environmental issues and promoting sustainable construction practices. Previous research indicates that RAC exhibits certain physical and mechanical deficiencies, with strengths 10% to 20% lower than natural aggregate concrete (NAC). At the structural level, RAC elements show reductions of up to 15% in axial, bonding, shear, and flexural strengths relative to NAC. Measures such as treatment of RCA, recycling process optimization, and optimized mixing techniques are recommended to enhance RAC properties. Prioritizing RCA treatment during construction and exploring novel strengthening techniques could elevate improve RAC and make it suitable for structural applications. The review also found that C&DW recycling efforts vary significantly across countries (particularly in Southeast Asia), with some countries lagging regarding recycling technologies and use of best practices. Various strategies to improve the performance of RAC elements are also proposed and discussed. The main findings and shortcomings of previous investigations are critically discussed, and further research needs are identified.