Mix Sustentável (Oct 2018)
CEMENT CONTENT REDUCTION IN CONCRETE THROUGH AGGREGATE OPTIMIZATION AND PACKING: A SUSTAINABLE PRACTICE FOR PAVEMENT AND SEAPORT CONSTRUCTION
Abstract
Based on the full-bodied scientific consensus that climate warming is occurring on Earth, significant environmental and economic benefits may be obtained from cement content reduction in concrete, naming reduction in CO2 emissions, energy consumption, and construction costs. In contrast, standard limestone aggregate may experience increase in mining rate. The objective of this study was to propose the reduction of cement content in concrete framed by aggregate optimization as a viable alternative to reduce environmental effects from the cement industry. It was concluded that the higher the concrete volume in construction, the more environmental benefit can be obtained by reducing cement content in concrete. A 25 % cement reduction in a concrete pavement led to a decrease of 80.000 tons in CO2 emission, while a seaport construction displayed a decrease of 17.000 tons of CO2. The higher the designed cement per volume of concrete, the more budget savings in case of reduction in cement content. Port construction presented a reduction of 20,10 USD per m3 of concrete in cement costs against 11,04 USD per m3 in pavements. A 11,5 % increase in aggregate mining is expected when concrete contains less cement in its composition, targeting South Florida (U.S.A.) quarries.
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