Modern high-strength steels achieve their strength exclusively through the manufacturing process, as the chemical composition of these steels is very similar to the composition of standard-quality steels. Typically, hot-dip galvanizing is used to form a protective zinc layer on the steel parts of structures; nonetheless, the material is exposed to high temperatures during the process. With high-strength steels, this can lead to deterioration of the mechanical properties. This study aims to experimentally examine and evaluate the extent of deterioration of the mechanical properties of high-strength-steel members. The effect was studied on specimens made of three different types of steel with the yield strength ranging from 460 to 1250 MPa. For each type of steel, selected mechanical properties—yield strength, tensile strength, and hardness—were determined on specimens with and without hot-dip galvanization, and the obtained results were mutually compared. Our study shows a significant impact of the hot-dip galvanization process on the mechanical properties of some high-strength steels. With the studied types of steel, the yield strength decreased by up to 18%, the tensile strength by up to 13%, and the hardness by up to 55%.

When used together with traditional grades of steel, the favourable mechanical properties of high-strength steels open up a wide range of applications in civil and engineering structures, both in primary structural elements and in individual parts. Modern high-strength steel markedly differs from the more traditional steel grades S355 and S235, not only in its mechanical properties but also in the fact that it requires different manufacturing techniques and heat treatment. The key problems that arise when welding high-strength steel to normal-strength steel are the choice of technical welding parameters, which take into consideration significant local heating effects, and the choice of suitable filler welding materials. The paper is focused on welded joints between components fabricated from high-strength steel with a yield strength of 700 MPa and elements made of traditional grade S355 and S235 steel.

Pinned joints are a basic type of mechanical joints for steel elements. They have been used in metal load-bearing structures since the middle of the nineteenth century. Due to their specific properties – the ability of the connected elements to rotate freely and the elimination of any bending moment transfer between the elements – pinned joints are designed for both steel and timber load-bearing structures. The BS EN 1993-1-8 standard lists simple rules for use when designing pinned joints. The procedures are based on design rules (recommendations) set out by E. Winkler in the latter half of the nineteenth century. In many layout and loading situations, such joints provide results that differ quite significantly from those obtained from precise numerical calculations or experiments. This paper focuses on issues concerned with the design of pinned joints. It deals with the options for the application of the design rules contained in BS EN 1993-1-8 during the design of such joints, and compares the results of these options both with three-dimensional numerical finite-element method models and with executed experimental measurements – load tests performed on joints. The obtained results for examples of specific joint layout and loading type are analysed.

Ventilated façade systems are being increasingly used in energy-efficient building envelopes due to their configurational flexibility and potential to reduce thermal bridging. This study focuses on the experimental evaluation of anchoring components used in such systems, specifically examining the effect of various thermal insulation pads and internal inserts on the system’s mechanical, thermal, and fire performance. A series of laboratory tests was carried out to assess the static behavior of aluminum brackets under both tensile (suction wind load) and compressive (pressure wind load) forces. The results demonstrate that the use of thermal pads and inserts does not lead to any significant degradation of the mechanical capacity of the anchoring brackets, confirming their structural reliability. Additional thermal testing revealed that the use of insulating materials significantly reduces heat transfer through the brackets. Fire resistance tests were conducted to compare the performance of different types of insulation pads under elevated temperatures. The findings indicate that the choice of pad material substantially influences both fire integrity and thermal performance. This study confirms the potential of incorporating optimized insulating pads and inserts into façade brackets to enhance the thermal and fire performance of ventilated façades without compromising their structural behavior.

This paper presents a brief information about problems of research, design and realization of steel tubular space structures based on the tradition started in the fifties at the Division of steel structures of the Technical University in Brno. Some examples of recent actual designs will be also presented and experience of analysis and detailing of tubular systems will be shortly discussed.