Avaliação ambiental do sistema construtivo de alvenaria de blocos de solo-cimento considerando diferentes especificações de projeto

Abstract

Este trabalho teve o objetivo de avaliar os potenciais impactos ambientais no ciclo de vida de diferentes especificações de projeto do sistema de alvenaria estrutural de blocos de solo-cimento. As alternativas avaliadas foram comparadas com a alvenaria estrutural de blocos cerâmicos e de concreto. Foi utilizada a metodologia de Avaliação do Ciclo de Vida (ACV). Foram comparados diferentes tipos de processo de produção de blocos de solo-cimento, considerando um processo manual e outro mecanizado. Foram também comparados dois tipos de cimento, CP-II-E-40 e CP-V-ARI e diferentes tipos de revestimento utilizados em uma parede de blocos de solo-cimento. A alternativa de alvenaria com blocos de solo-cimento com processo manual e com cimento CP-II-E-40 foi a mais vantajosa. As alternativas de alvenaria de blocos de solo-cimento apresentaram menores impactos ambientais que a alvenaria estrutural de blocos cerâmicos e de concreto para a maioria dos casos avaliados principalmente quando o revestimento de resina acrílica é considerado, com diferenças de até 77% para a categoria de Potencial de Aquecimento Global. A pesquisa contribui por mostrar, de forma quantitativa, o desempenho ambiental de diferentes alternativas do sistema de alvenaria de blocos de solo-cimento, para o contexto brasileiro. Os resultados apresentados, especialmente as diretrizes ambientais de projeto, podem auxiliar projetistas e construtores desse sistema construtivo

Is the Soil-Cement Brick an Ecological Brick? An Analysis of the Life Cycle Environmental and Energy Performance of Masonry Walls

“…For instance, hypothetically assigning a 50% allocation factor to an extra structural function for the concrete masonry examined herein, a non-structural soil-cement masonry would be outperformed in all categories assessed. On the other hand, considering structural soil-cement bricks and normalizing the functional unit for compressive strength, it would demand nearly 70% more raw material per m 2 •MPa-of which cement is a major portion-than concrete blocks [25,30], compared with 10% lower material demand without structural function as shown in this study.…”

“…The inclusion of finish coating layers was also examined. A layer of acrylic resin coating was considered on each side of the soil-cement wall with replacement every 5 years [25], and cement/sand mortar coating on each side of the wall for the three technologies, being 1.5 cm thick for soil-cement and concrete, and 3.0 cm thick for ceramic due to its smaller width [32,48].…”

“…In this study, soil-cement masonry bricks produced using a hydraulic press, PVA mortar wall joints, and resin coating, with 10 km-distant suppliers resulted in 16 kg CO 2 eq•m −2 and 160 MJ•m −2 . As for the carbon footprint, the consulted literature has reported results either in the same order of magnitude: 7 kg CO 2 eq•m −2 [12] and 12 kg CO 2 eq•m −2 [24]; or one order of magnitude higher: (80-100) kg CO 2 eq•m −2 [25]. Similarly, in terms of the energy footprint, the consulted literature reported 138 MJ•m −2 [24] and (700-800) MJ•m −2 [25].…”

“…As for the carbon footprint, the consulted literature has reported results either in the same order of magnitude: 7 kg CO 2 eq•m −2 [12] and 12 kg CO 2 eq•m −2 [24]; or one order of magnitude higher: (80-100) kg CO 2 eq•m −2 [25]. Similarly, in terms of the energy footprint, the consulted literature reported 138 MJ•m −2 [24] and (700-800) MJ•m −2 [25].…”

“…Similarly, Mpakati-Gama et al [24] reported a lower carbon footprint than ceramic and concrete, but a greater energy demand than concrete in Malawi. Caldas and Toledo Filho [25] reported better performance than ceramic and concrete structural masonry in Brazil for only a few indicators within a predefined set of categories in a given characterization method.…”