Análise da potencialidade da cinza do papel kraft na incorporação em concreto de cimento Portland

Abstract

The building construction industry plays a significant social and economic role in the country, bringing forth jobs and being responsible for a relatively large share of Brazil's gross domestic product. However, this is the largest industry about the generation of solid waste, a group of waste in which the bags of cements are framed. However, sack, which often do not receive adequate treatment because they are contaminated by cement impregnation, end up mitigating the environmental impact caused by construction. In the present work the potentiality of the kraft paper ashes from the cement sacks in the concrete incorporation of Portland cement is analyzed. This analysis was initiated by determining the pozzolan activity index of the ashes produced at temperatures ranging from 500 ° C to 1000 ° C by the modified Chapelle method. From this moment, the temperature of 900 ° C was adopted to produce the ash to be incorporated by means of mass substitution of cement in the contents of 5%, 10% and 15%. Although the ashes produced at 900 ° C returned the highest index of pozzolanic activity, the ash produced at all temperatures proposed had pozzolanic potential. Maintaining the trace and the fixed water / cement ratio, it was observed that the incorporation of the ashes did not entail significant changes of the concrete in its fresh state. Among the proposed incorporation levels, the 5% content presented the best strength gains.