ABSTRACT
The goal of this study was to discuss the contribution of pozzolan to the durability of reinforced mortars with addition of metakaolin used to strengthen non-load bearing walls. It is known that, from the 1960s, around 6,000 buildings have been erected with masonry sealing having structural function in the metropolitan region of Recife. These popular buildings are known as "box-type buildings" because they have the shape of a box due to the positioning of the apartments on four floors. They have high rates of pathologies and even fatal accidents. Despite the collapse of foundation walls, structural masonry has no substantiation regarding stability, particularly because the sealing blocks, which leads to insufficient support of the acting loads and sudden rupture. This way, we sought to establish criteria for strengthening with reinforced mortar within the matrix that meets three essential conditions: (i) support capacity; (ii) ductility and (iii) durability. In this work, we draw conclusions on durability, in which the experimental arrangement encompassed the specification of two proportions [(1:1:6:1.5 and 1:0.5:4.5:1.5)-cement, lime, sand, and water/cement ratio], with two contents of addition (8 and 15%) and two ways of addition (replacing part of the cement and with no cement replacement). Tests of compressive strength, elasticity modulus, velocity of ultrasonic wave propagation, absorption of water by immersion, and accelerated aging methods were conducted to assess the performance regarding carbonation and chlorides in mortar specimens. The results indicate that the metakaolin can substantially mitigate the action of deleterious agents, especially the samples with no cement replacement and 15% whit proportions (1:0.5:4.5:1.5).
Keywords:
Non-structural masonry; Reinforced mortar; Metakaolin
