Comparative process-based life-cycle assessment of bioconcrete and conventional concrete

Abstract

Purpose Bioconcrete is widely believed to be environmentally beneficial over conventional concrete. However, the process of bioconcrete production involves several steps, such as waste recovery and treatment, that potentially present significant environmental impacts. Existing life-cycle assessments of bioconcrete are limited in the inventory and impact analysis; therefore, they do not consider all the steps involved in concrete production and the corresponding impacts. The purpose of this study is to extensively study the cradle-to-gate environmental impacts of all the production stages of two most common bioconcrete types (i.e. sludge-based bioconcrete and cement kiln dust-rice husk ash (CKD-RHA) bioconcrete) as opposed to conventional concrete. Design/methodology/approach A cradle-to-gate life-cycle assessment process model is implemented to systematically analyze and quantify the resources consumed and the environmental impacts caused by the production of bioconcrete as opposed to the production of conventional concrete. The impacts analyzed in this assessment include global warming potential, ozone depletion potential, eutrophication, acidification, ecotoxicity, smog, fossil fuel use, human toxicity, particulate air and water consumption. Findings The results indicated that sludge-based bioconcrete had higher levels of global warming potential, eutrophication, acidification, ecotoxicity, fossil fuel use, human toxicity and particulate air than both conventional concrete and CKD-RHA bioconcrete. Originality/value The contribution of this study to the state of knowledge is that it sheds light on the hidden impacts of bioconcrete. The contribution to the state of practice is that the results of this study inform the bioconcrete production designers about the production processes with the highest impact.

Concrete water footprint: a streamlined methodology

“…Furthermore, most studies have a local connotation, whether based on local industry data, a local database or a local adaptation of database information, and thus they also use methods prevalently used in their region. Such an example is the North American TRACI method, which has been used by only 2 studies (Soleimani and Shahandashti 2017;Yazdanbakhsh et al 2018), both focusing on US territory results. Often, different versions of the same base method are used, whether it is because of the time when the study was carried out or because of indicators that are more convenient.…”

“…Regarding water-related impact considerations shown in Table 2-3, many of the studies also have an indicator in the final results that is related to water quality, such as acidification, eutrophication and, very rarely, ecotoxicity, but only four have an indicator concerning quantity of water (Serres et al 2016;Soleimani and Shahandashti 2017;Singh et al 2017;Fraj and Idir 2017). Moreover, Singh et al (2017) considers a water depletion indicator, whereas the rest consider it as water consumption.…”