Estudo da expansão por umidade e da resistência mecânica dos tijolos do edifício Aquarela, Jaboatão dos Guararapes-PE.

Abstract

The objective of the research was it of determining the Moisture Expansion and the Mechanical Flexural Resistance of the Aquarela Building's bricks, located in Jaboatao dos Guararapes-PR, whose structure entered in collapse in 1997. For this, were studied the bricks, the soil and the groundwater of the area where it was located the construction. The moisture expansion is a phenomenon that happens in some ceramic materials that contain anidrous silicates, that recombined with water in the liquid form or of vapor, they have as effect the increase of the dimensions of the ceramic piece, in an indefinite way, in a reason non constant and that decreases with the time. For the determination of moisture expansion, proof bodies were prepared with bricks affected and not affected by the action of the humidity, that were analyzed by the methods of the immersion, boiling in water, pressure cooker, autoclave and dilatometry that were to determine of current, total and future moisture expansion. After the analysis of moisture expansion the mechanical flexural resistance were accomplished in the same proof bodies. Were also prepared samples of milled bricks that were for the mineralogical characterization: differential thermal analysis, termogravimetry analysis and X-ray diffraction, they were still accomplished, the chemical analysis of the water and soil. The results obtained by the direct measurement they proved the phenomenon of the moisture expansion. The mineralogical characterization and chemical tests didn't justify the differences in moisture expansion of the affected bricks and the not affected. The mechanical flexural resistance tests showed that, after the "re-burning" of the bricks, happened a resistance earnings that practically equaled the tensions of rupture of the proof bodies a fleeted and not affected, differing in the proof bodies broken dry and humid. Just in the proof bodies not thermally treated occur evidences of the resistance loss in the affected bricks for the humidity. Through the study of the moisture expansion followed by the evaluation of the mechanical flexural resistance, were obtained subsidies to prove that the moisture expansion together with errors of execution of the work and employment of bad quality bricks was one of the main causes that contributed to the collapse of the construction. The results allow to conclude that was a loss of mechanical resistance due to suffered moisture expansion for the bricks.