Matéria (Rio de Janeiro)
versão On-line ISSN 1517-7076
SANTOS, F.I.G.; ROCHA, J.C. e CHERIAF, M.. Influence of bottom ash replaced natural aggregate and air-entraining agent in moisture transfer mechanisms in mortars. Matéria (Rio J.) [online]. 2007, vol.12, n.2, pp. 253-268. ISSN 1517-7076. http://dx.doi.org/10.1590/S1517-70762007000200003.
The study of moisture transfer has great importance for the characterization of mortars behavior, particularly in relation to durability, waterproofing, aesthetics degradation and the thermal performance. However, researches on properties related to moisture transfer mechanisms present applicable results only for conventional mortars. On the other hand, the use of industrial solid residues and admixtures are increasing in civil construction activities. The present work evaluated the properties related to moisture transfer mechanisms not only in conventional mortars, but also in mortars with 50% and 100% natural aggregate replaced by bottom ash, by volume, and with and without air-entraining agent. Bottom ash was chosen because it is a residue of great availability in southern Brazil, and its equilibrium moisture content is higher than that of sand, reflecting its porous nature. In relation to admixtures to cement-based materials, air-entraining agent deserves prominence because it increases the disconnection of the capillary network and decreases the specific gravity. The evaluated properties had been: specific gravity, porosity, water absorption by capillarity, air drying, water vapor sorption isotherms and apparent wetting angle. The results show that the bottom ash percentage and the air-entraining agent are parameters that significantly affect the properties related with the moisture transfer.
Palavras-chave : mortar; bottom ash; durability; moisture transfer; air-entraining agent.