Use of recycled aggregates for low carbon and cost effective concrete construction

JOURNAL OF CLEANER PRODUCTION

卷:189

Article

Bostanci, Sevket Can¹  Limbachiya, Mukesh²  Kew, Hsein² 

[1] European Univ Lefke, Fac Engn, Dept Civil Engn, TR-10 Mersin, Northern Cyprus, Turkey

[2] Univ Kingston, Sch Nat & Built Environm, Kingston Upon Thames KT1 2EE, Surrey, England

关键词: Initial surface absorption;    Carbonation;    Drying shrinkage;    Mineral admixtures;    Recycled glass sand;    Coarse recycled aggregate;   

DOI  :  10.1016/j.jclepro.2018.04.090

来源: Elsevier

【 摘 要 】

Reducing the carbon footprint of activities and a more prudent use of natural resources require for concrete production is a significant concern on the grounds of environmental and economical sustain ability. It is widely reported that the concrete industry contributes around 8% to total global carbon dioxide (CO2) emissions whereas cement utilization contributes approximately 90% of these emissions. Moreover, natural resources are becoming scarce and the world has become environmentally conscious. Against this background, reported work carried out to assess BS EN 197-1 cement concretes made with natural and partially substituted recycled aggregates and thus their suitability for use in low carbon cost effective concrete construction. In that respect, supplementary cementitious materials (SCMs) additive cements were selected to reduce the potential carbon footprint and establish fresh and hardened properties of natural aggregate concrete (NAC) mixes for equivalent 28-day compressive cube strengths of 40 and 50 N/mm(2). Then, a further investigation was carried out to assess the potential embodied CO2 (ECO2) emissions and cost analysis and performance of partially substituted recycled aggregates (coarse recycled aggregate (RA) and recycled glass sand (RGS) with proportions of 25% and 15% respectively by mass replacement). Results showed that SCMs incorporated NAC mixes has a potential to reduce ECO2 emissions and cost of concrete whilst partially substituted recycled aggregate concrete (RAC) mixes provided comparable ECO2 emissions but slightly increased cost for equal design strength. The loss of workability was found to be more for SCMs and recycled aggregate incorporated mixes. Studies of hardened concrete properties, comprising bulk engineering properties (compressive cube and cylinder strength, flexural strength, drying shrinkage) and durability (initial surface absorption) showed enhanced performance for SCMs concretes equivalent strength, except resistance to carbonation. However, the use of SCMs in RAC mixes slightly reduced the engineering and durability properties compared to corresponding NAC mixes. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free