Environmental Evaluation of Concrete Containing Recycled and By-Product Aggregates Based on Life Cycle Assessment

Rakhyun Kim,Won-Jun Park,Hoki Ban,Seungjun Roh

doi:10.3390/app10217503

Rakhyun Kim, Won-Jun Park + Show 2 more

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https://doi.org/10.3390/app10217503

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Abstract

This study aims to compare the potential environmental impact of the manufacture and production of recycled and by-product aggregates based on a life cycle assessment and to evaluate the environmental impact and cost when they are used as aggregates in concrete. To this end, the six potential environmental impacts (i.e., abiotic depletion potential, global warming potential, ozone-layer depletion potential, acidification potential, photochemical ozone creation potential, and eutrophication potential) of the manufacture and production of natural sand, natural gravel, recycled aggregate, slag aggregate, bottom ash aggregate, and waste glass aggregate were compared using information from life cycle inventory databases. Additionally, the environmental impacts and cost were evaluated when these aggregates were used to replace 30% of the fine and coarse aggregates in concrete with a design strength of 24 MPa. The environmental impact of concrete that incorporated slag aggregate as the fine aggregates or bottom ash aggregate as the coarse aggregates were lower than that of concrete that incorporated natural aggregate. However, concrete that incorporated bottom ash aggregate as the fine aggregates demonstrated relatively high environmental impacts. Based on these environmental impacts, the environmental cost was found to range from 5.88 to 8.79 USD/m3.

Highlights

Aggregates are important resources that account for 60–80% of the volume of concrete, and there is a continuously increasing demand for them
This was despite the fact that the environmental impact of waste concrete, which is the raw material of recycled aggregate, is close to zero
The potential environmental impacts caused by sand and gravel as well recycled, ash,environmental and waste glassimpacts aggregates

Summary

Introduction

Aggregates are important resources that account for 60–80% of the volume of concrete, and there is a continuously increasing demand for them. The supply and demand of aggregates, has been an important discussion point in the construction industry due to the management and regulation of the collection of natural aggregate for environmental conservation purposes in many countries. To address this supply and demand problem, the concrete industry has made considerable efforts to research and develop new concrete that incorporates recycled or by-product aggregate to replace some of the natural aggregate, while still ensuring the same level of quality (e.g., compressive strength and durability) associated with ordinary concrete that incorporates natural aggregate [1,2].

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