Adhesive mortars for stone plate bonding

Abstract

This work addressed the properties of adhesive mortars and the comparative study of their use for stone plate bonding. Tests were performed on the tiles of eight types of “granites” to compare the adherence of well-known mortar brands on the market, specifically for granites. Thus, an adhesive porcelain mortar (with comparable production cost) was used, developed by researchers at the Institute of Architecture and Urbanism–University of Sao Paulo, in addition to three laboratory-developed porcelain-based mortars. The rocks chosen were: grey swallow (monzogranite), yellow ornamental (garnet porphyroblastic gneiss), red Brasilia (syenogranite), Black Sao Gabriel (hypersthene diorite), green labrador (charnoquite), fantastic blue (biotite monzogranite megaporphyritic serial gnaissified), black Indian (migmatite), and rose jacaranda (nebulitic migmatite syenogranite) They did not have similar petrographic and sawability characteristics that resulted in different initial roughness values of the plates obtained by breaking apart the blocks on the gangsaw machine. The machine used granulated steel as an abrasive element. The adherence of these rocks with the mortars was determined on the rough surface by the pullout traction test, standardized for ceramics. It was observed that the laboratory-developed mortars showed excellent adherence and flexibility qualities; larger contact surfaces provided greater physical interaction, since the extremely low porosity of the rocks under study limited the anchoring adhesion process (penetration of mortar through the pores).