Research Interests:
Polyethylene from renewable resources produced using sugarcane as raw material was modified with phosphonium ionic liquids. Tensile properties and thermal behavior of modified biopolyethylene in air and nitrogen atmosphere were studied.... more
Polyethylene from renewable resources produced using sugarcane as raw material was modified with phosphonium ionic liquids. Tensile properties and thermal behavior of modified biopolyethylene in air and nitrogen atmosphere were studied. The thermal degradation of ionic liquids and their influence on thermal degradation of polyethylene from renewable resources were studied by thermogravimetric analysis (TGA). In general, modification of biopolyethylene with phosphonium ionic liquids resulted in improvement of tensile properties, i.e., tensile strength and Young’s modulus. Thermal degradation of biopolyethylene modified with phosphonium ILs proceeds in one step in the range of 400–500 °C in nitrogen atmosphere. Modification of polyethylene with trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate ionic liquid resulted in increase in DTGpeaks and T10% temperatures toward higher temperature for modified polyethylene in comparison with unfilled PE sample both in air and nitrogen atmosphere.
Research Interests:
During fire, there appear a lot of risks, including mechanical and thermal ones. To protect themselves, firefighters use special protection equipment. Helmets protect head and neck form falling debris or hitting invisible (under smoke... more
During fire, there appear a lot of risks, including mechanical and thermal ones. To protect themselves, firefighters use special protection equipment. Helmets protect head and neck form falling debris or hitting invisible (under smoke conditions) obstacles. What is more, helmets should be resistant to lateral deformation in case of strewing. The shell is the most essential and the most exposed to the danger part of a helmet. Numerous firefighters notice that during rescue or firefighting operations, the properties of a helmet shell change due to high temperature and as a result it gets distorted. Research was carried out on samples of polymer composite which is used in production of helmet shells by means of injecting it into molds. Temperatures and the exposure time were specified on the basis of exercise conditions in flash-over chamber and specialist literature.
Research Interests:
POIG.01.01.02-10-106/09-01.The paper presents results from the research of fire temperatures influence on steel-concrete bond and the estimation of this influence on bond reduction. In this paper the bond test results for ribbed steel... more
POIG.01.01.02-10-106/09-01.The paper presents results from the research of fire temperatures influence on steel-concrete bond and the estimation of this influence on bond reduction. In this paper the bond test results for ribbed steel B500SP and BSt500S to C30/37 concrete in the after-fire conditions (‘cold test’) including various cooling conditions therein shock cooling by water in the course of construction extinguishing actions and in the fire (‘hot test’) has been described. In all studied cases a significant reduction of bond was stated as a result of high temperatures. The research subject is closely related to the construction structures safety during the fire and the after-fire construction structures usability resulting from conducted extinguishing actions. The research has been carried out as part of project: ‘Innovative measures and effective methods of improving the safety and the durability of buildings and transport infrastructure in the sustainable development strategy’ POIG.01.01.02-10-106/09-01.
Research Interests: Engineering and Bond
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Composites based on LVL (Laminated Veneer Lumber) constitute the type of material which is more and more frequently used as construction elements in construction industry. Materials of this type can be characterized by other parameters as... more
Composites based on LVL (Laminated Veneer Lumber) constitute the type of material which is more and more frequently used as construction elements in construction industry. Materials of this type can be characterized by other parameters as the ones used for raw wood. Their strength properties are of key significance. In the case of majority of construction materials, the exposure to temperatures in the conditions of fire affects the increase of strength and reliability. The aim of the research presented in the article has been to evaluate the influence of increased temperatures on strength and reliability of LVL composite.Kompozity na bázi LVL představují druh materiálu, který je stále častěji používán jako stavební prvek. Materiály tohoto typu jsou charakterizovány podobnými parametry jako syrové dřevo. Zásadní význam mají pevnostní vlastnosti kompozit. V případě většiny stavebních materiálů ovlivňuje jejich pevnost a spolehlivost vystavení teplotám požáru. Cílem článku bylo zhodnot...
Research Interests:
The article presents results of experimental studies on mechanical properties of the polymer-composite material used in manufacturing firefighting helmets. Conducted studies included static and impact strength tests, as well as a shock... more
The article presents results of experimental studies on mechanical properties of the polymer-composite material used in manufacturing firefighting helmets. Conducted studies included static and impact strength tests, as well as a shock absorption test of glass fiber-reinforced polyamide 66 (PA66) samples and firefighting helmets. Samples were subject to the impact of thermal shocks before or during being placed under a mechanical load. A significant influence of thermal shocks on mechanical properties of glass fiber-reinforced PA66 was shown. The decrease in strength and elastic properties after cyclic heat shocks ranged from a few to several dozen percent. The average bending strength and modulus during the 170 degree Celsius shock dropped to several dozen percent from the room temperature strength. Under these thermal conditions, the impact strength was lost, and the lateral deflection of the helmet shells increased by approximately 300%. Moreover, while forcing a thermal shock oc...
Research Interests:
Conditions of firefighting –rescue actions, especially during internal fires are characterized by a number of threats. They mainly come from thermal and mechanical factors. Firefighter’s head is mainly exposed to mechanical threats,... more
Conditions of firefighting –rescue actions, especially during internal fires are characterized by a number of threats. They mainly come from thermal and mechanical factors. Firefighter’s head is mainly exposed to mechanical threats, protected by a firefighter helmet. The helmet absorbs part of mechanical impact energy in the direction of rescuer. The objective of the study was determination of central forces corresponding to impact energy of 60J and degree of redistribution of forces in a direction of cervical spine. The studies were conducted on the selected helmets at conditions of combined thermal and mechanical exposures (as it occurs in operating conditions). The studies have demonstrated that kinetic energy of impact to the helmet placed on the head is mainly exchanged to strain energy (deformation) of shell, protective insert, and if present a cradle. This process depends on the helmet’s construction. Temperature of thermal exposure impacting helmet is crucial for absorbing a...
The aim of the study was to determinate the fracture mechanism of firefighters’ helmets caused by the impact load in simulated operational conditions. Moreover the aim of the study was to assess the reliability of the personal protective... more
The aim of the study was to determinate the fracture mechanism of firefighters’ helmets caused by the impact load in simulated operational conditions. Moreover the aim of the study was to assess the reliability of the personal protective equipment. Tests were conducted with the use of the drop tower system. On each type of helmet 5 impact tests were performed. The active force corresponding to impact energy of 60 J and the passive force (force in the place of the neck spine) was registered. Based on the results, it can be statement that helmets’ structure influences their reliability and values of the active and passive forces. Additionally, the majority of tested helmets exceeded the acceptable threshold values of passive force.
Research Interests:
Research Interests:
Research Interests: Engineering and Logistyka
Research Interests:
Research Interests: Engineering and Logistyka
Research Interests:
The paper presents the results of the research into the impact of impregnation of wood on its bending strength and elastic modulus under normal conditions and after thermal treatment and investigates its structural reliability. Pinewood,... more
The paper presents the results of the research into the impact of impregnation of wood on its bending strength and elastic modulus under normal conditions and after thermal treatment and investigates its structural reliability. Pinewood, non-impregnated and pressure impregnated with a solution with SiO2 nanoparticles, was used in this research. The use of nanoparticles decreases the flammability of timber among others. Some of the tested samples were treated at 250 °C. This temperature corresponds to the boundary of the self-ignition of wood. This elevated temperature was assumed to be reached by a given speed of heating within 10 min, and then the samples were stored in these conditions for 10 and 20 min. The tests demonstrate that the bending strength of the impregnated wood was slightly improved, the impregnation did not impact the elastic modulus of the material in all such conditions, and the residual strength decreased less for the wood impregnated after being exposed to the e...
Research Interests:
A firefighter’s clothing as a personal protection used during rescue actions needs to fulfil several requirements in order to provide the optimum safety level. Author made an attempt to evaluate durability of the selected aramid material... more
A firefighter’s clothing as a personal protection used during rescue actions needs to fulfil several requirements in order to provide the optimum safety level. Author made an attempt to evaluate durability of the selected aramid material used as an outer layer of firefighter’s clothing. Verification of material’s durability was performed based on the tensile strength studies of the raw sample of material, and material subjected to accelerated aging in the chamber with xenon lamp and by Martindale’s abrasion cycles. The tensile tests were carried out in accordance with PN-EN ISO 13934-1:2013-07 standard, which specifies procedure to determine the maximum force of textile fabrics using a strip method.The test results show a decrease in the tensile strength of a fabric exposed to UV radiation and after abrasion cycles. In case of material exposure to UV radiation for 100 and 200 hours, reduction of strength by 34 and 48% was observed, respectively. Analysing the results obtained during...