Estudo sobre as características nos estados fresco e endurecido de uma argamassa para revestimentos estabilizada por 72 horas variando o tempo de aplicação a partir de sua mistura na central dosadora

Abstract

Stabilized mortars are scarcely diffused in the national market, consequently there’s not much information about them and much still has to be learned regarding application techniques, limitations and care. Therefore, the work presented here intends to investigate these mortars through their isolated behavior and also in the form of a coating and, with this, to draw methodologies that aim at the elaboration of practices that can analyze the characteristics of a mortar for coatings stabilized for 72 hours, composed of natural river sand, binders, chemicals and mineral additives, when applied on plated ceramic substrates. Mortar, still in the fresh state, was applied at time intervals of twelve hours from its mixing in the metering center, and due to the limitations the environment used for the study was the university’s laboratory interior, and at the time of each applications were performed consistency index, water retention, mass density and incorporated air content tests. After the curing time had elapsed, the mortar was submitted to mechanical strength tests, mass density and water absorption by capillarity. The tensile adhesion strength and the progress of cracking of the mortar coatings was also analyzed. The fresh mortar presented a loss of consistency index equivalent to 24,45%. Another information verified was the loss of entrained air in the mix while stabilization time, with consequent gain of mass density. In the hardened state, the mechanical strength increased until the period of 36 hours of stabilization, and after that began to decrease. Regarding the mortar coating itself the tensile strength increased to a time equivalent to 24 hours, after which it started to decrease until the final stabilization period, presenting significant effects in this attribute (sic).