Determinação das emissões de dióxido de carbono das matérias primas do concreto produzido na região norte do Rio Grande do Sul

Abstract

Resumo O concreto é um dos materiais mais usados na construção civil no Brasil, e seu uso difundido advém da grande facilidade de execução e adaptação às mais diversas formas. Reduzir o consumo dos materiais envolvidos na produção do concreto é uma das maneiras de buscar uma maior sustentabilidade da construção civil. Estas reduções de consumo de materiais, se avaliadas levando-se em conta também os impactos que a produção e o transporte dos mesmos geram no meio ambiente, podem vir a aprimorar ou redirecionar as conclusões ou decisões a serem tomadas em relação à busca de uma maior sustentabilidade ambiental. Dentro deste enfoque foram levantadas e avaliadas as emissões de dióxido de carbono (CO2), impactos ambientais gerados quando da extração/produção e transporte até o local de utilização das matérias primas do concreto. Juntamente foram levantadas e avaliadas as emissões na produção e transporte do concreto até a obra. Dentre as conclusões do estudo constatou-se que menores resistências características do concreto produzirão menores emissões de CO2, e que a influência do transporte nas emissões é significativa devido às longas distâncias percorridas pela maior parte das matérias primas.

Avaliação da sustentabilidade de habitações de interesse social a partir da especificação de materiais e elementos de edificação

“…In the end, the results obtained from the sustainability index related to the environmental aspect were averaged. These values were adopted based on researches by Bessa (2010), Saade et al (2014), Caldas (2016) and Santoro and Kripka (2016). These studies are inserted in the Brazilian context, with a scope defined as "cradle to the grave"…”

Studies on Environmental Impact Assessment of Reinforced Concrete in Different Life Cycle Phases

“…The amount of CO 2 emitted by the concrete with additives was 47% lower (a significant reduction) when compared to the concrete without any addition. Santoro and Kripka (2016) proposed the determination of CO 2 emissions parameters from the production and transportation of raw materials and from the production and transportation of the concrete to the work site, to be used in the design of concrete structures by considering the environmental issue. To evaluate the results obtained, they concluded that producing a concrete with a higher strength will produce a greater amount of CO 2 in the environment, mainly because the cement will be present in greater quantity.…”

“…Kim et al (2016) If concrete mix and raw material suppliers were carefully selected, it can be obtained a reduction of 34% in the emission of CO 2 and 1% in the costs Park et al (2012) CO 2 emissions increase linearly with the compressive strength of the concrete; to similar strengths, the concrete produced in the winter presented an increase of approximately 5% in the CO 2 emissions Santoro and Kripka (2016) Higher strength concrete will produce a greater amount of CO 2 ; the CO 2 emissions during transport are significant Choi et al (2016) For smaller loads the increase of the transversal area of concrete is more advantageous for the eduction of O 2 emissions, and for greater loads the increase of the steel profile produces a more sustainable solution Berndt (2015) The use of smaller resistances is advantageous in relation to CO 2 emissions; the choice of the concrete mixture strongly influences the magnitude of the CO 2 emissions Yang et al (2015) The intensity of CO 2 emissions gradually decreases as Portland cement is replaced by complementary cementitious materials (up to 20%) García-Segura et al (2014) In comparison to Portland cement, despite the reduction in CO 2 capture and life time, 80% blast furnace slag cement emitted 20% less CO 2 per year Cabello et al (2016) To reduce the environmental impact generated by a structure, the focus should be on phases of production of raw materials, transportation and production of concrete Oliveira et al (2014) It is not appropriate to base decisions on the emissions of concrete solely on the strength of the concrete and the type of cement used, since the variations are significant Paya-Zaforteza et al (2009) Minimization of embedded CO 2 emissions and economic cost seem to be highly related Park et al (2013) Reducing the amount of steel and increasing the amount of concrete can be an effective way to reduce the structural costs and CO 2 emissions of columns Habert and Roussel (2009) It is also possible to combine cement replacement and increase mechanical strength Possan et al (2016) Concrete during its life time can absorb from 40 to 90% of CO 2 emitted in the manufacturing process; the absorption of CO 2 is directly proportional to the surface area of concrete exposed to CO 2 , and influenced by the type of cement and resistance to concrete. Park et al (2014) Increasing the strength of the structural materials used is more efficient in reducing CO 2 emissions and costs than increasing the quantities of structural materials used Collins (2013) If carbonation is ignored, emission estimates can be overestimated by up to 45% depending on the strength of the concrete that was used as well as the type of construction application that incorporates recycled concrete during the second generation Yepes et al (2012) CO 2 emissions and costs are closely related.…”

Emissões de CO2 de sistemas de revestimento de argamassa: estudo de caso de aplicação de argamassa projetada comparativamente à aplicação convencional

“…O Brasil encontra-se entre os maiores emissores de gás carbônico proveniente de atividades industriais no planeta, ocupando o sexto lugar no ranking global (SANTORO;KRIPKA, 2016;SEEG..., 2017). A indústria da construção contribui significativamente para a emissão dessesgases, que, juntamente com outros gases, tais como o metano, formam os gases de efeito estufa (GEE) (AYE et al, 2012).…”