A tile system for external cladding comprises the tiles, a substrate, a necessary fixative to adhere the tiles on to the substrate adhesive., and a grouting material to seal the pointing gaps between the tiles Fig. 1..
Although normally designed as non-loadbearing, such a system always responds to the environment with differential movements due to its composite nature. For example, tiles are inclined to have an irreversible
moisture expansion, while its cementitious substrate, on the contrary, tends to permanently shrink on drying. If the bonding strength between the different constituents is sufficient, the tendency of the differential movements may be constrained, causing high build-up
of stresses and possible damages in weaker constituents of the system. In other cases where the bond strength is weak, more differential movements may realise, leading to a disintegration of the composite system at the interface between the layers w1]3x.
The common causes for wall tile failures are:
1. deformation of adhesive or mortar. onto which the tiles have been laid due to shrinkage, etc.;
2. differential movements between the tile, adhesive and the immediate substrates, due to thermal, moisture or other effects;
3. failure of the cement rendering behind the adhesive;
4. structural movements, shrinkage and creep, vibrations and settlement problems;
5. improper surface preparation such as inadequate cleaning, no provision of proper keys;
6. improper design and selection of materials; and
7. improper sequence of work.
A detailed analysis of the important factors causing adhesion failures is critical for a proper design and construction strategy to prevent the problem from occurring. The objectives of this study are to study the
effect of temperature and movements on adhesive strength