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.

The use of construction sealants is an important area not just of the building construction. Each building requires a careful processing of all details and façades are no exception. From today´s point of view we may note that sealing of façade joints and different types of cracks, fissures or gaps is nothing unusual and, therefore, it is astonishing that there still occur defects that often cause a significant decrease of the durability of the structures and sealed structures. This paper deals with testing of a selected group of construction sealants at a so-called ‘real joint’. The real joint is a term defining a set of testing samples when the testing body contains a sealant applied in a manner corresponding to its real application. Cement bonded particleboard board was representing the façade cladding in this research since during the sealing there often occur complications with adhesion of sealants. For the presented experiment the existing testing methods that are used for verification of adhesion of cladding materials were studied and modified. According to the opinion of the authors those modified methods simulate well the parameters of the external environment and thus also the negative influences that may have a significant impact on the sealed joint in practice. The measured results prove that in the application of the sealants it is very important to follow the technology discipline and namely it is necessary upfront to verify whether the chosen materials are compatible. In most tested cases, diversion from the above-given steps resulted in failure of the sealed joint.Použití stavebních tmelů je důležitou oblastí nejen konstrukce budovy. Každá budova vyžaduje pečlivé zpracování všech detailů a fasád není výjimkou. Z dnešního pohledu lze poznamenat, že utěsnění fasádních kloubů a různé typy prasklin, trhlin nebo mezery není nic neobvyklého, a proto je úžasné, že se stále vyskytují závady, které často způsobují významné snížení trvanlivosti Konstrukcí a uzavřených konstrukcích. Tento článek se zabývá zkoušením vybrané skupiny stavebních tmelů na takzvaném "skutečném spojení". Skutečný spoj je termín definující sadu testovacích vzorků, když zkušební těleso obsahuje těsnicí prostředek aplikovaný způsobem, který odpovídá jeho skutečnému použití. Dřevotřísková deska s cementovou deskou reprezentovala fasádní obklady v tomto výzkumu, protože během těsnění se často vyskytují komplikace s přilnavostí těsnicích materiálů. Pro předložený experiment byly studovány a modifikovány stávající testovací metody, které se používají pro ověření adheze obkladových materiálů. Podle názoru autorů tyto modifikované metody dobře simulují parametry vnějšího prostředí a tím i negativní vlivy, které mohou v praxi významně ovlivnit utěsněný kloub. Naměřené výsledky dokládají, že při aplikaci těsnicích materiálů je velmi důležité dodržovat technologickou disciplínu, a to je nutné předem ověřit, zda jsou zvolené materiály kompatibilní. Ve většině testovaných případů způsobilo odklon od výše uvedených kroků selhání uzavřeného kloubu

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.

One of the current issues in the Czech building industry is an efficient implementation of seal joint between constructions. An undesirable penetration of water, moisture or air between structural elements may have a negative effect on their reliability and may also affect the length of expected service life. This issue is addressed in detail in the following paper. The experimental part of the research is aimed at ascertaining the technical properties of sealants and on verification of their potential usage in practise. Furthermore, this article focuses on the preparation and subsequent production of test specimens, and also on the experimental verification of their tensile properties at a temperature of (20 ± 3) °C and (-22 ± 2) °C. For the tests, composite high pressure laminates (i.e. HPL Trespa Meteon) are chosen for the cladding. In order to find the best solution ten types of commonly manufactured industrial sealants is selected. At the same time the emphasis was on representation of sealants in various price categories. The main conclusion of tests 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 selected cladding material. Moreover, the method also suggests that the use of the most expensive sealant does not always provide the best results.Jedním z aktuálních problémů v českém stavebnictví je řešení realizace tmelených spojů. Nežádoucí pronikání vody, vlhkosti nebo vzduchu mezi konstrukčními prvky může mít negativní vliv na jejich spolehlivost a může také mít vliv na délku očekávané životnosti. Tato problematika je řešena v následujícím příspěvku. Experimentální část výzkumu je zaměřena na zjištění technických vlastností tmelů a na ověření jejich možného využití v praxi. Kromě toho, je tento příspěvek zaměřen na přípravu a následnou výrobu zkušebních vzorků, a také na experimentální ověření jejich mechanických vlastností při teplotě (20 ± 3) °C a (-22 ± 2) °C. Pro účely zkoušek byl vybrán kompozitní vysokotlaký laminát (tj. HPL Trespa Meteon) pro opláštění. S cílem nalézt nejlepší řešení bylo vybráno deset druhů běžně vyráběných průmyslových tmelů. Zároveň byl kladen důraz na zastoupení tmelů z různých cenových kategorií. Stěžejním závěrem zkoušky je skutečnost, že není možné odpovědně zvolit vhodný materiál a tmel bez předchozích zkušeností nebo experimentálního odzkoušení

The presented paper summarizes the main research findings on the impact of the environment concerning the durability and service life of building joint sealants. The focus is placed on sealed joints in façade applications, which can serve different purposes and can also be several meters long which often intensifies the stresses that the joint needs to withstand and therefore its service life can be significantly shortened. Different approaches, test sample geometries and high-performance sealants, were used in this context to determine the most critical aspects for the studied application sector. The research was divided into three phases where the joints were subjected to (I) artificial weathering in a laboratory environment, (II) real weathering in an external environment, and (III) weathering via a real application that was monitored for almost 4 years. The extensive research scope confirmed one commonly known presumption, that standardized artificial weathering/aging methods are not able, from a long-term perspective, to simulate the impact of a real environment. The most valuable results were obtained in the third phase of the research, where the monitoring of a real façade brought to light completely different conclusions. The joints exposed to the real environment were either completely deteriorated or showed signs of advanced aging.