The cost of most primary materials is increasing, therefore, finding innovative solutions for the re-use of residual waste has become a topic discussed more intensely in recent years. WPCs certainly meet some of these demands. The presented study is focused on an experimental analysis of the effect of surface treatment on the adhesive properties of selected WPCs. Bonding of polymer-based materials is a rather complicated phenomenon and modification of the bonded area in order to improve the adhesive properties is required. Two traditional types of surface treatments and one entirely new approach have been used: mechanical with sandpaper, chemical with 10 wt % NaOH solution and physical modification of the surface by means of a MHSDBD plasma source. For comparison purposes, two high-density polyethylene based products and one polyvinyl-chloride based product with different component ratios were tested. A bonded joint was made using a moisture-curing permanently elastic one-component polyurethane pre-polymer adhesive. Standardized tensile and shear test methods were performed after surface treatment. All tested surface treatments resulted in an improvement of adhesive properties and an increase in bond strength, however, the MHSDBD plasma treatment was proven to be a more suitable surface modification for all selected WPCs.

Facades are a key element in creating modern building designs. Their area is up to ¾ of the total area of the outer surface, and this also largely influences the interior of the building. The choice of the type of sheathing structure is not only dependent on the appearance or requirements of the indoor environment but also on the maintenance, the lifetime of the structure and the assembly technology. Ventilated facades, known as "Cold Facades", are an appropriate solution. The principle of these structures is based on the airflow in the gap between the outer and inner parts of the sheathing. The exterior cladding makes the visual aspect of the building and protects the structure against climatic influences. The inner part ensures the thermal, acoustic or fire requirements [1].

The paper describes an experiment focusing on the way the material system influences the bond strength of large-format tiles installed on concrete substrate during mechanical loading under conditions that correspond to real-life application. This involves a controllable mechanical load applied over an area of a test model while observing its condition using non-destructive methods (ultrasonic pulse velocity test, acoustic emission method, strain measurement, and acoustic tracing). The model consisted of a concrete slab onto which were mounted four different systems with large-format tiles with the dimensions of 3 m × 1 m. The combinations differed in the thickness of the tile, the adhesive, and whether or not a fabric membrane was included in the adhesive bed. The experiment showed that the loading caused no damage to the ceramic tile. All the detected failures took place in the adhesive layer or in the concrete slab.

Precise adherence to the manufacturer’s instructions and requirements plays an important role in various installation processes. The presented paper deals with the evaluation of the effect of manufacturing imperfections and surface defects on the failure behaviour of flexible adhesive intended for façade application. The failure to comply with the accepted procedures is more common in construction practice than in other sectors of the industry, mostly due to the surrounding conditions and lack of trained supervision. Unfortunately, this may lead to premature failure of adhesively bonded joints and a considerable shortening of the service life of the entire construction. To determine the potential of the risk, five types of artificially applied (a) manufacturing imperfections: (1) application on wet adhesion promoter, (2) application after the expiry of the laying-time, (3) curing of samples at +1℃ (b) surface defects: (4) application on a wet substrate and (5) application on a dirty surface, were suggested. Moreover, the Taguchi L32 orthogonal array design was used to arrange the test setup of all possible combinations. The 1 K polyurethane adhesive was applied in tensile butt joints and single-lap shear joints composed of aluminium alloy and thermally modified wood substrates. The obtained results confirmed that non-observance of the required manufacturing techniques and recommended procedures can have a negative impact on the decrease of the adhesively bonded joint strength and deformation behaviour. Surprisingly, the most critical was not the combination of all suggested types of imperfections and defects. The performed one-way ANOVA revealed that the most perilous was the combination of types 2 and 4 in the tensile test with 77% joint strength reduction. In the shear test, the most critical was the combination of all types of imperfection and defects which led also to a 77% drop of shear strength.

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This research was carried out as part of project MPO FR - TI4/332 – New Technologies of Bonded Facade Cladding with Anchor Elements with Increased Resistance to Corrosion.This contribution concerns tests carried out to investigate the tensile properties of silicone sealants for use with facade cladding materials. The experimental part of the research is aimed at ascertaining the technical properties of sealants via the cyclic alternation of extension and compression of test specimens in test moulds. For the tests, industrially manufactured neutral and universal silicones were chosen from three different manufacturers. The aim of the research was to discover any differences that might appear in their resistance against alternating maintained extension and compression of the specimens under extreme temperature conditions, i.e. a high temperature of (70+2) °C and a temperature simulating freezing, i.e. (-20+2) °C. The cladding material used was fibre-cement composite boards (known as Cembonit), ceramic and glass cement facade claddings.The result of the measurements taken is a summary in which effective and unsuitable combinations of sealants and test substrates are outlined. The main conclusion is the fact that it is not possible to responsibly choose a suitable material without taking appropriate measurements or having previous experience. A secondary conclusion to this article is the fact that there are significant differences between individual sealants in the results they provide in combination with specific cladding material.

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