Alexandre Alves


Durabilidade de argamassas poliméricas de agregados leves

The aim of this study is to evaluate the durability of polymeric mortars with lightweight aggregate facing several environmental agents. For this purpose, it was investigated the effect of wet-drying cycles in saline environments, with the soaking in salt water and drying inside a climatic chamber. Furthermore, it was evaluated the effect of wet-drying cycles in acidic environments, using sulfuric and formic acid solutions.
In this study it is analyzed the behavior of four types ofepoxy resin polymer mortars with a concentration of 85% by weight, with two types of filler (cork powder and rubber powder) with a concentration of 15%.
The wet-dry cycles in saline environment consisted on immersing the specimens in salt water for 20 hours, followed by 20 hours of drying at 50ÂșC and cooling at room temperature for 2 hours, this consisting on a 24 hour cycle. Specimens were removed at 60 cycles and at 120 cycles in which the loss of weight and strength were evaluated.
The research of the effect of sulfuric acid immersion consisted on immersing the specimens on different types of sulfuric acid solutions (5, 10, 15, 20 and 30%) for 7 days and then to be dried in an oven for 7 days. After each cycle the specimens were weighted to evaluate its mass loss. Five cycles of immersion-drying were made.
The effects of wet-dry cyclesin formic acid were evaluated by immersing the specimens in a formic acid solution with a concentration of 10% and were made the same number of that have been made for the immersion in sulfuric acid study. At the end of each cycle the specimens were weighted and at the 5th cycle, compression tests were also made.