Key Engineering Materials Vol. 898

Abstract: This paper deals with the problematics of utilization of waste perlite from production of expanded perlite in polymer-based material. The goal of this paper is to develop repair mortar containing as high amount of waste perlite as possible as substitution for filler. The resulting mortar exhibits very high physical-mechanical properties such as high bonding strength to a large variety of building materials. The microstructure and the re-dispersibility of filler were also studied.

Abstract: It is assumed, that the pore content is related to other parameters of CIPP liners such as mechanical properties and service life or durability of pipelines. The article examines the pore structure of two different materials - composites pipes cured with steam and UV light. The pore structure was examined using an optical microscope and X-ray computed tomography (CT). The aim of the work was to verify the applicability of some methods for verifying the volume of air/gas in the cured composite.

Abstract: External wooden structures have own place in the building industry for ages. The problem is that wood easily degrades due to UV radiation, atmospheric conditions and biological aggressors. We are trying to eliminate degradable factors by photocatalytic materials (namely titanium oxide). Those materials are efficient UV absorbers and they are able to destroy biological aggressors also. Nowadays, there is no information about the interactions between wooden surface and non-photoactive or photoactive forms of TiO₂. TiO₂ exists in many morphological forms. The planar particles were chosen for the purpose of our research and applied on a wooden surface. The samples of wood (namely pine) were monitored for 255 days and subsequently evaluated using an electron microscope. The use of TiO₂ was compared with reference material and a reference commercial coating.

Abstract: Concrete filled steel tubes (CFST) represent a composite building member suitable especially for the construction of columns of a skeleton frame. Filling the steel tube with concrete allows the use of suitable properties of both materials and their interaction. This is very beneficial in a fire exposure, where a circular column has slightly better fire resistance than a square column. In case of an assessment of columns at the ultimate limit state (ULS), a buckling resistance decides. In previous research, it was found that increasing the strength of concrete increases buckling resistance only to a certain extent. The main aim of the article is to show through a theoretical study what benefit the use of ultra-high strength concrete has for buckling resistance of CFST.

Abstract: Wood is a versatile material able to be used in a wide variety of situations and applications. Wood has also very good strength to weight ratio. Problem is degradation of wood due to bad external conditions. The protection of wood takes many forms including proper design detailing. The majority are directed towards the prevention of moisture access and weathering. However, there are also some design details that can also assist in reducing the risk of biological attack. Our work provides a background on a number of important subjects related to good performance of wooden structures. This paper deals with durability of wood, design for durability of wooden structures, surface modification of wood and also evaluation and monitoring of wooden structures.

Abstract: In common practice, we encounter cases where it is not possible to test the wood quality by destructive methods and it is, therefore, necessary to use non-destructive or semi-destructive methods, especially when the wood is already used in construction. The article deals with the methodology of non-destructive and semi-destructive testing of wooden structures using the methodology commonly used for the diagnosis of masonry structures, where mortar strength is tested using a so-called Kučera drill, and with verification of the applicability of this method in the testing of wood properties. Kučera drill was specially modified for the purpose of the experiment and its functionality was tested. The depth of penetration of the drill into the test specimen was tested. The article describes the principle of measurement and the design of the initial experiment, but also the pitfalls, which had to be faced.