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It is now recognized that the construction sector is one of the main generators of Construction and Demolition Waste (CDW) and emissions of greenhouse gases (GHG) worldwide. While nationally there is Resolution 0472 of 2017 to carry out proper management of the CDW, it is important to analyze the influence of compliance with this standard in the generation and GHG possible reduction nationwide. For this reason, the present research aims to technically assess the relationship between policy management component RCD (Resolution 472, 2017) and reducing the carbon footprint in the first phase of the construction cycle, setting a case study one high-rise building located in the Medellin city. Four scenarios of compliance with Programa de Manejo Ambiental (PMA) were proposed based on different concrete mix designs of compressive strength 24 MPa, also evaluating the carbon footprint of each scenario. Concrete mix designs presented the inclusion of superplasticizer admixtures, partial substitutions of cement for fly ash and / or partial substitutions of virgin aggregates for recycled aggregates. The results showed that in order to comply with the CDW regulations, the partial replacement of virgin aggregates with recycled aggregates is strategic (scenario 3), but for the reduction in the carbon footprint, the partial replacement of cement with fly ash, including superplasticizer admixtures, is important (scenario 2). Therefore, the stage 4 which links all the above strategies has high percentages of compliance (17.2% versus 11.3% in the baseline scenario) and a reduction in carbon footprint (338.1 kg CO2/m² versus 438.1 kg CO2/m² in the baseline scenario). [ABSTRACT FROM AUTHOR]

The mine tailings cause several environmental impacts, due to high and progressive mineral exploitation and waste management. Alkaline activation to manufacture building materials using waste as supplementary cementitious materials has been a widely used method. In this article, mortars with alkali-activated mine tailings has been studied. Vein gold tailing wastes, were activated by a mixture of NaOH and Na2SiO3 solution. Two types of mortars were analyzed to assess influence of particle size were manufactured, the first by using original granulometry tailing and the second with milled residue. In addition, each type of mortar was set at 24 and 80 °C. Crystalline phases in mortars were identified by X-ray diffraction (XRD), and the morphology of the fracture surfaces after the compression test was analyzed with scanning electron microscopy (SEM). The results show that the compressive strength of the specimens produced from milled residue was higher value in comparison with original granulometry specimens. In addition, setting temperature increase did not have an influence on the property evaluated. [ABSTRACT FROM AUTHOR]