Concrete water footprint: a streamlined methodology

• Autor(a) principal: Mack Vergara, Yazmin Lisbeth
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: http://www.teses.usp.br/teses/disponiveis/3/3146/tde-16092019-144335/
• topic: Cementitious materials; Ciclo de vida (Avaliação); Concreto; Construção sustentável; Construction materials; Consumo de água; Life cycle assessment; Materiais cimentícios; Materiais de construção; Sustainable construction; Sustentabilidade; Water consumption

Water is the most used substance in the world, followed by concrete. Water scarcity is nowadays more common due to concentrated population growth and climate change. Concrete demand is ~15 billion m3 per year fulfilling the need for more and better housing and infrastructure for a growing and wealthier population. Since no other material could fulfil this demand, concrete needs to be produced in a sustainable way, minimizing environmental loads such as water consumption. The water footprint is a tool that measures water use over a products\' life cycle and estimates its potential environmental impacts. Despite the growing concern on water, the existing water footprint methodologies are too complex and require large amounts of data. This study develops a streamlined water footprint methodology for concrete production, simple enough to be useful to the industry and robust enough to be environmentally meaningful. An extensive study on existing water footprint methodologies have been conducted. Then a streamlined methodology was proposed focused on the water flows that are more relevant in concrete production including water quantity and quality letting to meaningful results with less data. Typical water inventory includes the batch water (150-200 H kg/m3), dust control (500-1500 H kg/day), truck washing (13-500 H kg/m3), cement production (0.185-1.333 H kg/kg) and aggregates production (0.116-2.0 H kg/kg). Regarding water quality, the most critical flows - Zinc, Lead, Nitrate, Nitrogen oxides and Sulfur dioxide- were identified based on the contribution of these flows to the potential environmental impacts, the control or influence that the concrete producer has on the activities were these flows appear and the feasibility to measure these flows on site. Concrete water footprint varies due to mix design, technological routes, location and choice of impact assessment method. The results are of interest to the research community as well as to the stakeholders of the cement and concrete industries and a contribution to sustainable construction since study of water footprint is fundamental to improve water efficiency.