Filtry
wszystkich: 2046
wybranych: 1724
-
Katalog
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: ROAD PAVEMENT CONSTRUCTION
-
Microcrack monitoring and fracture evolution of polyolefin and steel fibre concrete beams using integrated acoustic emission and digital image correlation techniques
PublikacjaThe use of polymer and steel fibres in plain concrete appears to be an excellent solution for limiting crack propagation and improving the post-ductility performance of concrete structures. Based on this premise, this study investigated the fracture evolution of polyolefin fibre-reinforced concrete (PFRC) and steel fibre-reinforced concrete (SFRC) specimens through the integrated application of two diagnostic techniques, acoustic...
-
The effect of elevated temperature on the properties of cement mortars containing nanosilica and heavyweight aggregates
Publikacja -
Effect of incorporation route on dispersion of mesoporous silica nanospheres in cement mortar
Publikacja -
Mechanical properties cement based composites modified with nano-Fe3O4/SiO2
Publikacja -
Grouts with highly thermally conductive binder for low-temperature geothermal applications
Publikacja -
Nanocomposite of cement/graphene oxide – Impact on hydration kinetics and Young’s modulus
Publikacja -
The effects of Fe3O4 and Fe3O4/SiO2 nanoparticles on the mechanical properties of cement mortars exposed to elevated temperatures
Publikacja -
Mechanical properties and interfacial transition zone microstructure of concrete with waste basalt powder addition
Publikacja -
Cement composites with expanded graphite/paraffin as storage heater
Publikacja -
The effects of silica/titania nanocomposite on the mechanical and bactericidal properties of cement mortars
Publikacja -
Effect of perlite waste addition on the properties of autoclaved aerated concrete
Publikacja -
Gypsum dehydration in cement and its impact on air-void structure in air-entrained concrete
Publikacja -
Sustainable utilization of copper post-flotation waste in cement composites
PublikacjaThe current way of managing the copper ore flotation waste is by placing it in waste neutralization facilities. However, flotation waste has great potential in application in cement composites. The article presents the detailed characteristics of post-flotation waste (PFW) and three types of cements: CEM I, CEM II/B-V, and CEM III/A, 42.5 MPa class. The post-flotation waste added for 20% of the cement mass increase the water demand...
-
Guided ultrasonic waves for detection of debonding in bars partially embedded in grout
PublikacjaThis paper deals with theoretical, numerical and experimental investigations of guided wave propagation in multilayered cylindrical bars with pre-existing debonding. The research focuses on a complex description of the nature of the wave phenomena occurring in a debonded specimen with a special emphasis on the influence of the location of damage on the wave conversion and diffraction. Experimental non-destructive and destructive...
-
Application of Electrochemical Impedance Spectroscopy to evaluate cathodically protected coated steel in seawater
PublikacjaTwo types of organic coated carbon steel (S235JR2 grade) electrodes were exposed to artificial seawater environment. One prepared type was defect free while the other one had an intentionally introduced φ0,5 cm coating defect. Both kinds of samples were polarized during the exposure to four potentials corresponding to four different cathodic protection levels. Evolution of their EIS spectra is presented in this paper. Results obtained...
-
Mechanical and fracture properties of concrete reinforced with recycled and industrial steel fibers using Digital Image Correlation technique and X-ray micro computed tomography
PublikacjaPaper presents investigation of fracture phenomenon in plain concrete and in concrete reinforced with both recycled steel fibers (RSF) and industrial steel fibers (ISF). The wedge splitting test (WST), which enables stable crack propagation for quasi-brittle materials, was carried out on 75 75 75 mm cube samples. Initially, fracture process zone development was investigated only on the surface of samples using Digital Image Correlation...
-
Time evolution of Electrochemical Impedance spectra of cathodically protected steel in artificial seawater
PublikacjaUsability of Electrochemical Impedance Spectroscopy data for better cathodic protection control was investigated. Carbon steel – S235JR2 grade specimen were exposed in artificial seawater environment. Samples were polarized and their potentials corresponded to four different cathodic protection degrees. Time evolution of Electrochemical Impedance spectra was investigated. Goodness of fit function (X2) was analysed in terms of proper...
-
Reference-free determination of debonding length in reinforced concrete beams using guided wave propagation
PublikacjaThis paper presents theoretical and experimental investigations of guided wave propagation in reinforced concrete beams, with pre-existing debonding between steel rebars and concrete blocks, for the purpose of damage detection. The primary aim of these investigations was a detailed analysis of the possible applications of wave propagation in single and multiple debonding detection in reinforced concrete structures and reference-free...
-
Asphalt concrete subjected to long-time loading at low temperatures – Deviations from the time-temperature superposition principle
PublikacjaThe article presents the observed deviations from the time-temperature superposition principle of asphalt concretes, tested in the bending beam creep test at low temperatures for a long time of loading. In almost all tested asphalt concretes, deviations appeared after 500 s of loading at the temperature of -10 C. Some types of bitumen presented deviations at other temperatures – usually the harder the grade of the bitumen, the...
-
Influence of cooling rate and additives on low-temperature properties of asphalt mixtures in the TSRST
PublikacjaThe paper presents the results and analysis of low-temperature properties of asphalt mixtures according to Thermal Stress Restrained Specimen Test (TSRST) and Indirect Tensile Test methods. Different groups of bitumen were investigated: neat, SBS-modified and highly SBS-modified. Influence of cooling rates (1 C/h, 3 C/h, 5 C/h and 10 C/h) and additives (aramid fibres and crumb rubber) was identified as well. Moreover, for each...
-
Effect of bitumen characteristics obtained according to EN and Superpave specifications on asphalt mixture performance in low-temperature laboratory tests
PublikacjaThe paper aims to identify those characteristics of bitumen which have the greatest impact on asphalt mixture low-temperature performance. It was observed that stiffness and m-value of bitumen from BBR test were moderately related to stiffness and m-value of asphalt mixture obtained from 3 PB test. Simultaneously those rheological properties significantly impact on cryogenic stresses induced during TSRST test. The multiple regression...
-
A novel heterogeneous model of concrete for numerical modelling of ground penetrating radar
PublikacjaThe ground penetrating radar (GPR) method has increasingly been applied in the non-destructive testing of reinforced concrete structures. The most common approach to the modelling of radar waves is to consider concrete as a homogeneous material. This paper proposes a novel, heterogeneous, numerical model of concrete for exhaustive interpretation of GPR data. An algorithm for determining the substitute values of the material constants...
-
Hydrogen embrittlement of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints under cathodic protection
PublikacjaThe effect of cathodic polarization conditions on hydrogen degradation of X2CrNiMoCuN25-6-3 super duplex stainless steel welded joints, obtained using flux cored arc and submerged arc welding methods, was evaluated. Slow strain rate tensile tests of base material and welded specimens, ferrite content measurements, scanning electron microscopy observations, and statistical analysis were performed. It was found that hydrogenation...
-
FEM and experimental investigations of concrete temperature field in the massive stemwall of the bridge abutment
PublikacjaThe paper deals with the prediction of early-age concrete temperature of cast-in-place stemwall of the bridge abutment. The considered object is an arch bridge located in Gda´nsk. In the case of massive structures, it is particularly important to not exceed the temperature difference between the core and the concrete surface. Too high temperature gradient generates an increase in thermal stresses, what could be the reason of exceeding...
-
Mechanical, durability, depolluting and electrical properties of multifunctional mortars prepared with commercial or waste carbon-based fillers
PublikacjaCarbon-based fillers from industrial wastes and commercial ones were compared to improve the properties of lime-based mixes. As commercial fillers, graphene nanoplatelets and activated carbon were used, whereas as industrial wastes a char obtained by the gasification of biomasses and a used foundry sand were chosen. Carbon-based wastes were found to be a good cost-effective alternative to commercial carbon based fillers to increase...
-
Impact response of two-layered grouted aggregate fibrous concretecomposite under falling mass impact
PublikacjaTwo-layered Grouted Aggregates Fibrous Concrete Composite (TGAFCC) is a new category concrete which became popular recently and attracted the attention of researchers globally. Recent studies indicated that TGAFCC has notable improvement in mechanical properties, which has been sufficiently documented. However, the impact behaviour of TGAFCC when combined with Glass Fibre Mesh (GFM) and Textile Fibre Mesh (TFM) is still unexplored....
-
Detection of debonding in reinforced concrete beams using ultrasonic transmission tomography and hybrid ray tracing technique
PublikacjaThis paper concerns inspection of reinforced concrete elements, with particular emphasis on assessing the quality of the adhesive connection between steel and concrete. A novel theoretical model was developed to determine the paths of transmitted, refracted and reflected elastic waves as well as a creeping wave propagated along the inclusion surface. Imaging the internal structure of tested beams was based on wave propagation measurements...
-
Modification of thermal and rheological characteristics of bitumen by waste PET/GTR blends
PublikacjaWaste poly(ethylene terephthalate) (wPET)/ground tire rubber (GTR) blends with variable compositions were applied as low-cost modifiers into bitumen and their performance has been evaluated via morphological, thermal and rheological analyses. Depending on the weight ratio of wPET/GTR, dispersion of single/composite domains of waste polymers in the bitumen has promoted the interaction between bitumen and blend components. Fourier...
-
The influence of combination of binding agents on fatigue properties of deep cold in-place recycled mixtures in Indirect Tensile Fatigue Test (ITFT)
PublikacjaThe publication presents fatigue properties of cold recycled mixtures for eight combinations of binding agents (cement and bituminous emulsion). Cold recycled mixtures were evaluated in Indirect Tensile Fatigue Test (ITFT) at the temperature of 20 C in controlled stress mode. As a function of horizontal stress, fatigue life is strongly influenced by combination of the binding agents. When fatigue life is analyzed as a function...
-
Mechanical and radiation shielding properties of concrete reinforced with boron--basalt fibers using Digital Image Correlation and X--ray micro--computed tomography
PublikacjaThe paper presents experimental investigations of the radiation shielding, mechanical and fracture properties of concrete reinforced with 5 kg/m3 of novel basalt fibers infused with boron oxide (BBF). However, further studies concerning other dosages i.e. 1 kg/m3, 10 kg/m3, 15 kg/m3 and 20 kg/m3 are currently carried out. Experiments with neutron source revealed that addition of BBF as a dispersed concrete reinforcement could improve...
-
Investigations on fracture in reinforced concrete beams in 3-point bending using continuous micro-CT scanning
PublikacjaThis study explores a fracture process in rectangular reinforced concrete (RC) beams subjected to quasi-static three-point bending. RC beams were short and long with included longitudinal reinforcement in the form of a steel or basalt bar. The ratio of the shear span to the effective depth was 1.5 and 0.75. The focus was on the load–deflection diagram and crack formation. Three-dimensional (3D) analyses of the size and distribution...
-
Experimental investigations on water sorptivity in mortars with the use of X-ray micro-CT system.
PublikacjaW pracy doswiadczalnej zbadano zjawisko sorpcji wody w pryzmatycznych próbkach zapraw, które jest ściśle powiązane z trwałością materiału. Sorpcyjność oceniana na etapie ustalonym w połączeniu z warunkami zewnętrznymi może być wykorzystana do przewidywania okresu użytkowania. Sorpcyjność początkową i wtórną wody w próbkach zapraw nienasyconych zmierzono w badaniach laboratoryjnych zgodnie z normą amerykańską ASTM C 1585–04. Wpływ...
-
Curb-to-Barrier Face Distance Variation an a TB51 Bridge Barrier Crash Test Simulation
PublikacjaThis paper addresses the problem of road safety regarding barrier placement as relative to the curb. A short summary of existing regulations is presented. Numerical simulations using the explicit finite element system Ls- Dyna are shown. In the analysis, variable distance between the barrier and the curb is assumed. The obtained result reveals that the distance has little impact on the working width of the barrier.
-
On the durability of the hydraulic satellite motor working mechanism in overload condition
PublikacjaThe paper presents the newest construction of the hydraulic satellite pump/motor. In this study, the fracture of the hydraulic satellite motor working mechanism is investigated. Factors influencing the durability of satellite working mechanism have been described. The durability of the hydraulic satellite motor working mechanism at a load, corresponding to a pressure of 15 MPa supplied with refined rapeseed oil is very low. Analyses...
-
Entasis- shape of beauty
PublikacjaTwo algorithms for the construction of entasis given by [2,3] are examined in this study. It has been shown, that those shapes are not an ellipse for which they were considered by the authors, but another curves.
-
Entasis- shape of beauty
PublikacjaTwo algorithms for the construction of entasis given by [2,3] are examined in this study. It has been shown, that those shapes are not an ellipse for which they were considered by the authors, but another curves.
-
Modelling of joining route segments of differential curvature
PublikacjaThe paper presents a new general method of modelling route segments curvature using differential equations. The method enables joining of route segments of different curvature. Transitional curves of linear and nonlinear curvatures have been identified in the case of joining two circular arcs by S-shaped and C-oval transitions. The obtained S-shaped curves have been compared to the cubic C-Bezier curves and to the Pythagorean hodograph...
-
Comparison of calculated and measured thermal stresses in asphalt concrete
PublikacjaThe paper presents the comparison of calculated and measured thermal stresses induced in restrained asphalt concrete specimens by cooling. Thermal stresses were measured in the Thermal Stress Restrained Specimen Test. The calculations of thermal stresses were performed with the use of a theoretical formula based on the temperature dependent stiffness modulus. The novel approach applied in this paper was that the stiffness modulus...
-
Equivalent axle load factors for design of rigid pavements derived from fatigue criteria
PublikacjaArtykuł przedstawia określenie współczynników równoważności osi dla nawierzchni sztywnych na podstawie kryteriów zmęczeniowych stosowanych w mechanistyczno-empirycznej metodzie projektowania nawierzchni drogowych. Przedstawiono kryteria zmęczeniowe z wybranych metod projektowania i analizy nawierzchni sztywnych. Kryteria te zostały użyte do wyprowadzenia wzorów do obliczania współczynników równoważności obciążenia osi. Stwierdzono,...
-
Limit States of Shallow Bridge Foundations With Sheet Piling Covers
Publikacja -
Constructing a map of an anonymous graph: applications of universal sequences
PublikacjaWe study the problem of mapping an unknown environmentrepresented as an unlabelled undirected graph. A robot (or automaton)starting at a single vertex of the graph G has to traverse the graph and return to its starting point building a map of the graph in the process. We are interested in the cost of achieving this task (whenever possible) in terms of the number of edge traversal made by the robot. Another optimization criteria...
-
Chapel at St. Joseph's Church in Gdańsk
PublikacjaThe subject of this article is the chapel located in the former Gdańsk Carmelite monastery complex. The results of the architectural research carried out in it in 2014–2015 are presented. As a result, the time and purpose of the building’s construction were established. The original appearance and traces of later alterations were also recognised. The recesses found on the longitudinal walls, of similar dimensions, not reaching...
-
R&D of satellite pumps and motors with small geometrical displacement supplied with oil and non-flammable liquids
PublikacjaThe newest construction of satellite motors and self-suction satellite pumps with small geometrical displacement have been described in this article. The characteristics of volumetric and total efficiency of one satellite motor, selected from the series, supplied with oil have been presented. These characteristics have been compared with the orbital motors' characteristics. The remaining specifications of these motors were also...
-
Improving Effectiveness of SVM Classifier for Large Scale Data
PublikacjaThe paper presents our approach to SVM implementation in parallel environment. We describe how classification learning and prediction phases were pararellised. We also propose a method for limiting the number of necessary computations during classifier construction. Our method, named one-vs-near, is an extension of typical one-vs-all approach that is used for binary classifiers to work with multiclass problems. We perform experiments...
-
The dependence of linear viscoelasticity limits of cold-recycled mixtures on time of curing and compaction method
PublikacjaCold-recycled mixtures are currently among the most widely used and investigated methods that enable recycling of old pavement structures in an environmentally friendly manner. Upon milling, the old pavement structure – whose gradation can be improved with addition of virgin aggregate – is mixed and compacted at ambient temperature. The main binding agents are bituminous emulsion and cement. Due to their dual binding behaviour,...
-
Cold recycled mixtures for binder courses - laboratory evaluation of mechanical properties
PublikacjaCold recycled mixtures composed with cement and bituminous emulsion are nowadays commonly used material for base layer. Typical pavement with cold recycled mixtures usually consists of two asphalt courses (wearing and binding course) constructed over cold recycled base. Therefore the next step in cold recycling is possibility of design of binding courses with recycled materials, but with potential to obtain high quality mixtures...
-
an intelligent image processing sensor - the algorithm and the hardware implementation
PublikacjaW artykule przedstawiono algorytm przeznaczony do rozpoznawania obiektów ruchomych w obrazie do celu analizy ruchu pojazdów. Algorytm został zrealizowany w układzie FPGA.Ang.: This paper describes the idea and theimplementation of the robust algorithm dedicated toextraction of moving vehicles from real-time cameraimages for the evaluation of traffic parameters, suchas the number of vehicles, their direction of movementand their...
-
A Novel Spatio–Temporal Deep Learning Vehicle Turns Detection Scheme Using GPS-Only Data
PublikacjaWhether the computer is driving your car or you are, advanced driver assistance systems (ADAS) come into play on all levels, from weather monitoring to safety. These modern-day ADASs use various assisting tools for drivers to keep the journey safe; these sophisticated tools provide early signals of numerous events, such as road conditions, emerging traffic scenarios, and weather warnings. Many urban applications, such as car-sharing...
-
Identification of safety hazards and their sources in tram transport
PublikacjaBoth in Poland and in most countries of the European Union, the tram infrastructure is extensively expanding. Contemporary low-floor trams are constructed according to different technical assumptions than typical railway vehicles or high floor trams. In Poland such vehicles rides often on lines designed according to standards developed to the classical vehicles. At the same time, the intensity of road traffic and the number of...
-
Badania czynników wpływających na bezpieczeństwo ruchu drogowego w województwach
PublikacjaWojewództwa stanowią podstawową jednostę zarządzania w Polsce. Jak dotąd mało rozpoznanym proble-mem są czynniki wpływające na bezpieczeństwo ruchu dro-gowego na poziomie województw. Na podstawie przeglądu literatury zidentyfikowano metody analiz bezpieczeństwa na poziomie regionanym a także niektóre czynniki wpływające na bezpieczeństwo ruchu na obszarze regionów. Następnie zebrano dane dostępne dla województw w Polsce w...