Influência do tipo de junta de assentamento no comportamento mecânico de alvenarias confeccionadas com tijolos ecológicos

Abstract

Ecological brick masonry constructions are widely carried out due to their practicality, low cost and sustainability. Given this, earthen construction technology becomes attractive in developing countries due to its ease of implementation and low cost. It has also become attractive to developed countries because it has a sustainable characteristic, when compared to conventional construction methodologies. This work proposes the study of the influence of laying joints on the mechanical behavior of masonry made with ecological bricks. To this end, an experimental program was developed including prisms and small walls constructed with different types of joints: laying mortar, adhesive mortar and PVA glue. The average compressive strength of ecological bricks was influenced by different humidity conditions: oven-dried (10.47MPa), ambient condition (6.92MPa), with relative humidity of 90% (5.79MPa) and saturated (3.88MPa ). The adhesive mortar and conventional mortar presented compressive strength 1.36 and 0.99 times the compressive strength of bricks, respectively. The compressive strength of prisms and small walls was also impacted by the joints, with values being: 3.26MPa and 4.86MPa (adhesive mortar), 2.84MPa and 4.01MPa (conventional mortar), 1.86MPa and 1.87MPa ( PVA). This converged to an increase in compressive strength of 75% and 52% for adhesive and conventional mortar (respectively) in relation to PVA prisms and a 2.60 and 2.14 times increase for these small walls. The rupture mode observed in the sticky mortar and conventional mortar prisms was due to traction in the bricks. In the small walls, in addition to the traction in the bricks, the crushing of the units on the sides of the test specimens was also observed. As for the prisms and small PVA glue walls, traction cracks were observed throughout the entire test piece in addition to the crushing of the units, characterized by the chipping of debris. It is concluded that the laying joint, which in addition to solidifying the bricks, had the function of uniformly transmitting the efforts, avoiding the accumulation of tensions and local failure of the units, giving the ecological brick system greater resistance. Among the types of joints studied, the one that presented the best efficiency in distributing internal stresses was the adhesive mortar, possibly due to its greater resistance to compression and traction/adhesion due to the presence of polymeric additions in addition to cement.