Per: EVANDRO TOLENTINO (CENTRO FEDERAL DE EDUC TECNOLOGICA DE MG), Raquel salgado Batista (Centro Universitário do Leste de Minas Gerais, UNILESTE-MG), Dyandra Lorayne Souza Pereira (CENTRO UNIVERSITÁRIO DO LESTE DE MINAS GERAIS, UNILESTE-MG), Armin Franz Isenmann (CENTRO FEDERAL DE EDUC TECNOLOGICA DE MG)
Abstract:
Kraft process is one of the major alkaline process used to convert wood to pulp. The solution obtained after the removal of the fiber is named black liquor, a very complex liquid, consisted of high alkalinity and high dissolved solids such as lignin residues, degraded carbohydrates and inorganic constituent. In this study the use of lignin from black liquor as chemical admixture for Portland cement mortars was investigated. Cement paste and mortar mixtures were prepared with 0.05% wt., 0.1% wt., 0.3% wt., and 0.5% wt. lignin addition, and they were tested for workability and setting time. From results it was shown that lignin addition did not modified the workability performance of mortars. However, 0.3% wt., and 0.5% wt. of lignin addition increased cement pastes setting time, proving that lignin could act as set retarder.