Material flow analysis and material use efficiency of Brazil's mortar and concrete supply chain

Abstract

Cementitious materials, mostly concrete and mortar, account for about one‐third of all materials extraction worldwide. Material flow data in this industry are still unsatisfactory, especially related to unused extraction materials, quarry wastes, and water consumption, aspects which usually are not included in environmental analysis studies. The aim of this study is to conduct a material flow analysis (MFA) of the Brazilian concrete and mortar supply chain to quantify material use efficiency (ME) and dematerialization potential. The MFA includes extraction, production, and construction stages for the following indicators: i) unused extraction; ii) quarry waste; iii) water consumption; iv) material wastage; v) raw material consumption; vi) energy carriers; and vii) atmospheric emissions. The results demonstrated that the primary raw material footprint is about 456 million metric tons (Mt) corresponding to a metabolic rate of 2.2 metric tons/capita (t/capita). After including unused extraction, quarry wastes, water consumption, and secondary materials this value increases to 4.1 t/capita corresponding to a total material consumption of 840 Mt. Concrete and mortar can be produced using two routes—mixing on site or industrial mixing. We conclude that the industrial scenario allows for dematerialization by about 8% for concrete and 24% for mortar, by mass; and the average material use efficiency is low, at about 53% for concrete and 34% for mortar.

The role of cement service-life on the efficient use of resources

“…Improving yield loss during manufacture, where possible (e.g. [62]), and reducing over-ordering of material for construction projects also fall under the category of improving material efficiency measures that could aid in environmental impact mitigation. Further, engineering concrete to provide necessary properties with less material or with less weight can reduce material flows associated with the concrete as well as potentially with structural systems needed to support the concrete.…”

Harea berdeen erabilera morteroen eroankortasun termikoa aldatzeko

“…Industria eta eraikuntza sektoreetan geroz eta lehengai gehiago kontsumitzen direnez, jasangarritasunak garrantzia handia hartu du azken urteotan. Eraikuntza sektorean hormigoiak eta morteroak izanda gehien erabiltzen diren eraikuntzamaterialak [1,2], lehengai naturalez osatuta daude gehienbat, bere osagai nagusiak -harea eta zementua-harrobietatik lortutako harri natural desberdinak tratatuz lortu behar baitira. Hori dela eta, hormigoiak eta morteroak fabrikatzeak duen karbono-aztarna murrizteko bi alternatiba nagusi daude: zementuan, Portland klinkerraren erabilera murriztea, baliabide naturalak eta ekoizpen energia murrizteko, eta harea naturalen erabilera murriztea.…”

“…Horrela, geroz eta bero espezifiko bolumetriko eta eroankortasun termiko altuagoak izan, gutxiago eta motelago berotuko da diskoa. Gustafsson-en arabera [17], sentsorearen "∆T" tenperatura igoerak "τ" denbora adimentsionalarekin erlazio lineala dauka (1):…”