Effect of Supplementary Cementitious Materials on Reduction of CO2 Emissions From Concrete

LCA of recycled and conventional concretes designed using the Equivalent Mortar Volume and classic methods

“…8 The materials used for the elaboration of the concrete mixes were cement polycarboxylates, and air entraining admixture (AE; Micro-Air 100). The RA was 12 produced entirely by recycling concrete material and was classified according to 13 the EN 933-11 standard [37].The results of these concrete characteristics come 14 from an extensive experimental campaign [25]. Their composition and main 15 results are detailed in Table 1 water/cement ratio (w/c), minimum cement content, and minimum air content.…”

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

“…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.…”

“…In addition, Yang et al (2015) examined the efficacy of complementary cementitious materials such as blast furnace slag, fly ash and active silica in reducing the CO 2 emissions of Portland cement used in concrete production by assembling and analyzing a comprehensive database, including 5294 laboratory concrete mixtures and 3915 concrete mixtures under construction. Compressive strength ranges from 8 to 170 MPa and substitution levels of 3 to 80% blast furnace slag, 3 to 70% fly ash and 3 to 40% active silica were considered.…”

Influência de agregados reciclados de concreto na reologia do concreto

“…Além disso, a indústria de concreto também é responsável por uma parcela significativa das emissões globais de gases do efeito estufa [2].…”