Uso de lama de carbonato de cálcio gerada no processo kraft como material de enchimento em concreto asfáltico usinado à quente

Abstract

The use of solid waste in hot-machined asphalt concrete has the potential to provide an economic gain not only for the sector in which they are generated, but also in sectors such as civil construction, especially when these industrial wastes have basically constituted of inorganic material. The general objective of this work was to evaluate the technical feasibility of using calcium carbonate slurry, generated in the KRAFT process, as a filling material, in the production of hot-machined bituminous asphalt mixture. In the methodology used, based on the respective regulations in force, the reference trace of the asphalt mixture was determined based on the Marshall dosage, measuring the optimal content of petroleum asphalt cement (PAC) and also the percentage of residue (sludge of calcium carbonate) that would best fit the trace. Mixtures with 2%, 3% and 4% calcium carbonate slurry were tested. For the stability and creep parameters, the results did not show a statistically significant difference, despite increasing up to a certain amount of LCC inserted in the mixture. As for the percentage of voids and bitumen-voids ratio, the values showed a statistically proven improvement, even verified by the analysis of the images using a magnifying glass, where in the mixture with 4% there were signs of exudation from the CAP, thus indicating the possibility of decreasing the percentage of voids. CAP in its composition, thus demonstrating its potential for use as a filler in hot-machined asphalt mixtures.