Abstract

Researchers put significant effort to decrease the environmental impact of concrete by using industrial by-products as an alternative binder. However, the considerable environmental impact still exists due to the consumption of natural resources as aggregates. Natural aggregates are the most used resources by volume in the construction sector. Therefore, it is necessary to investigate by-products as an alternative to natural aggregates as well. This study presents the environmental impact of lightweight concrete (LWC) produced by replacing natural aggregates with recycled waste plastic (polyethylene) (RWP) and partially replacing Portland cement with Class F fly ash (FA). Life Cycle Assessment (LCA) was performed to compare a conventional LWC, containing pumice as natural aggregate and Portland cement as a binder, with green LWC, containing 30% RWP as pumice replacement and 20% FA as cement replacement. These scenarios were evaluated in terms of global warming potential, abiotic depletion, ozone layer depletion, terrestrial ecotoxicity, photochemical oxidation, acidification and eutrophication. LCA was coupled with mechanical tests at 7 days and 28 days. RWPs were found to be an environment-friendly replacement material for natural lightweight aggregates with an overall decrease in all CML-IA impacts except eutrophication. Tested green mix design also provided sufficient strength for nonstructural applications.

摘要

研究人员通过使用工业副产品作为替代粘合剂，努力减少混凝土对环境的影响。然而，由于自然资源作为总量的消耗，仍然存在相当大的环境影响。天然骨料是建筑行业使用量最大的资源。因此，有必要研究副产品作为天然骨料的替代品。本研究介绍了用再生废塑料（聚乙烯）（RWP）替代天然骨料和用 F 级粉煤灰（FA）部分替代波特兰水泥生产的轻质混凝土（LWC）对环境的影响。进行生命周期评估 (LCA) 以比较传统的 LWC（含有作为天然骨料的浮石和作为粘合剂的波特兰水泥）与绿色 LWC，含有 30% RWP 作为浮石替代品和 20% FA 作为水泥替代品。这些情景根据全球变暖潜力、非生物消耗、臭氧层消耗、陆地生态毒性、光化学氧化、酸化和富营养化进行了评估。LCA 与 7 天和 28 天的机械测试相结合。RWP 被发现是天然轻质骨料的环保替代材料，除富营养化外，所有 CML-IA 影响都总体下降。经过测试的绿色混合设计也为非结构应用提供了足够的强度。LCA 与 7 天和 28 天的机械测试相结合。RWP 被发现是天然轻质骨料的环保替代材料，除富营养化外，所有 CML-IA 影响都总体下降。经过测试的绿色混合设计也为非结构应用提供了足够的强度。LCA 与 7 天和 28 天的机械测试相结合。RWP 被发现是天然轻质骨料的环保替代材料，除富营养化外，所有 CML-IA 影响都总体下降。经过测试的绿色混合设计也为非结构应用提供了足够的强度。