Durability Assessment of Adhesive Systems for Bonding Ceramic Tiles on Façades: The Research and the Practice

Abstract

The aim of this work is to give a contribution for the assessment of the durability of adhesive systems for bonding ceramic tiles on façades, based on experimental works carried out at the Building Physics Laboratory, Faculty of Engineering, University of Porto, Portugal (LFC—FEUP), in the perspective of both the research and the possible practical applications. The durability assessment of any construction material is not an easy task. The researchers must choose between several different approaches, each of which has advantages and limitations. While, in a building in use, the materials or components are subjected to varying actions in an environment where the great majority of the degradation agents are not controllable by man, in a laboratory, one can choose to expose the materials to artificial and controlled conditions, using climatic chambers for accelerated ageing. The main difficulty of this type of test lies in the interpretation of the results, in what concerns their correspondence to real time. Researchers on durability have been discussing this problem for a long time: how to get a valuable correlation between the results of accelerated ageing tests and the one issued from natural exposure. This work is presented in two different stages. In a first stage, a discussion on durability assessment is presented based on an experimental research study, concerning the performance over time of different types of cementitious adhesives exposed to accelerated ageing tests and also to natural ageing. The main advances and the main difficulties in implementing a service life prediction model are identified. Suitable strategies are discussed for the future development of this approach. In a second stage, an extensive case study is presented. The main goal of this case study is to evaluate the durability of alternative adhesive systems for bonding ceramic tiles on the façades of a building, located near the sea. For this purpose, accelerated ageing tests are performed following two different ageing procedures, allowing the comparison of the performance over time of the systems under analysis.