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Wyniki wyszukiwania dla: transparent concrete
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Study of fracture process in concrete using a discrete lattice model.
PublikacjaW artykule omówiono wyniki numeryczne z zastosowaniem dyskretnego modelu rusztowego złożonego z belek do symulacji procesu zarysowania w elementach betonowych. Obliczenia wykonano dla różnych procesów obciążeniowych. Wyniki porównano jakościowo z wynikami doświadczeń.
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Modelling of concrete behaviour with a non-local continuum damage approach
PublikacjaW artykule przedstawiono wyniki numerycznej dla różnych problemów brzegowych związanych z powstawaniem rys w betonie. Obliczenia wykonano przy zastosowaniu modelu zniszczeniowego (z uwzględnieniem degradacji sztywności). Do opisu rys, model rozszerzono o nielokalność.
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The dynamic thermal properties of aerogel-incorporated concretes
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MAGAZINE OF CONCRETE RESEARCH
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Preliminary Studies on a Lightweight Porous Cement-Based Composite – Gel Concrete
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Impact of Surfactant and Calcium Sulfate Type on Air-Entraining Effectiveness in Concrete
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Experimental Verification of Natural Vibration Models of Steel-concrete Composite Beams
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Vibration of Steel–Concrete Composite Beams Using the Timoshenko Beam Model
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REINFORCED CONCRETE SUPPORTING CONSTRUCTION OF THE STADIUM COVER FOR EURO 2012 IN GDAŃSK
PublikacjaIn the article structural issues that connected with the reinforced concrete supporting construction of the stadium roofing for EURO 2012 in Gdańsk were described. In the first part of the article the concept of stadium foundation were described. In the second the static - strength analysis for two variants fastening together individual foundation elements were made. The two assumed geometrically different concept of foundation...
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COMPUTER-AIDED CONSTRUCTION AT DESIGNING REINFORCED CONCRETE COLUMNS AS PER EC
PublikacjaThe article presents the author’s computer program for designing and dimensioning columns in reinforced concrete structures taking into account phenomena affecting their behaviour and information referring to design as per EC. The computer program was developed with the use of C++ programming language. The program guides the user through particular dimensioning stages: from introducing basic data such as dimensions, concrete...
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Development of 3D printed heavyweight concrete (3DPHWC) containing magnetite aggregate
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Experimental and Numerical Investigations of the Effect of Curing Conditions on the Temperature Rise of Concrete
PublikacjaThis paper presents experimental and numerical studies investigating the impact of three curing conditions on temperature evolution in concrete cubes. The tests were performed on samples of the same volume (3.375 dm3) under different curing conditions: room temperature, insulation boxes, and adiabatic calorimeter. Various cements (Portland cement, Portland composite cement, and blast furnace slag cement) and aggregates (gravel...
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Influence of Actual Curing Conditions on Mechanical Properties of Concrete in Bridge Superstructures
PublikacjaThis article presents the research on the mechanical characteristics of concrete in the construction of three concrete bridges. A system of recording the internal temperature of concrete and automatic control of laboratory ovens was used for specimen curing. This allowed the specimens to be cured under conditions similar to those occurring in the structure. Before the construction, reference blocks were used to define similar curing...
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Influence of the Addition of Recycled Aggregates and Polymer Fibers on the Properties of Pervious Concrete
PublikacjaThe aim of the study was to check the possibility of reusing aggregate from recycled concrete waste and rubber granules from car tires as partial substitution of natural aggregate. The main objective was to investigate the effects of recycled waste aggregate modified with polymer fibers on the compressive and flexural strength, modulus of elasticity and permeability of pervious concrete. Fibers with a multifilament structure and...
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Guided wave propagation for assessment of adhesive bonding between steel and concrete
PublikacjaAdhesive bonding is becoming more increasingly important in joining of structural elements. In civil engineering, there is a growing interest in connection by adhesive bonding in steel-concrete flexural members. This study concerns the guided wave propagation technique applied to condition assessment of an adhesive connection between a steel member and a concrete beam. Various states of degradation were considered by producing...
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High Rise Building: The Mega Sculpture Made Of Steel, Concrete and Glass
PublikacjaHigh rise building has transformed from providing not only the expansion of floor space but functioning as mega sculpture in the city. The shift away from economic efficiency driven need is only expected to grow in the future. Based on literature studies; after analysing planning documents and case studies, it was examined whether the presumption that gaining the maximum amount of usable area is the only driving factor; or if the...
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A novel formulation of 3D spectral element for wave propagation in reinforced concrete
PublikacjaThe paper deals with numerical simulations of wave propagation in reinforced concrete for damage detection purposes. A novel formulation of a 3D spectral element was proposed. The reinforcement modelled as the truss spectral element was embedded in the 3D solid spectral finite element. Numerical simulations have been conducted on cuboid concrete specimens reinforced with two steel bars. Different degradation models were considered...
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Numerical modeling of GPR field in damage detection of a reinforced concrete footbridge
PublikacjaThe paper presents a study on the use of the ground penetrating radar (GPR) method in diagnostics of a footbridge. It contains experimental investigations and numerical analyses of the electromagnetic field propagation using the finite difference time domain method (FDTD). The object of research was a reinforced concrete footbridge over a railway line. The calculations of the GPR field propagation were performed on a selected cross-section...
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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...
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RMS-based damage detection in reinforced concrete beams: numerical simulations
PublikacjaImage-based damage detection methods using guided waves are well known and widely applied approaches in structural diagnostics. They are usually utilized in detection of surface damages or defects of plate-like structures. The article presents results of the study of applicability of imaging wave-based methods in detection in miniscule internal damage in the form of debonding. The investigations were carried out on numerical models...
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The effect of macro polymer fibres length and content on the fibre reinforced concrete
PublikacjaThe paper presents studies of a ready-mix concrete containing polymer fibres of three different lengths: 24, 38 and 54 mm. The performed tests allowed to determine the effect of fibre volume fraction and length on the concrete strength. The basic parameters of concrete mixture (consistency, air content and bulk density) were identified. Fibre reinforced concrete belongs to a group of composite materials. The polymer fibres are...
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Degradation of the Concrete Railway Track Bed Located in the Vicinity of the Loading Wharf
PublikacjaThe following article describes the damages of the concrete railway track bed at the place of unloading petroleum products located in the immediate vicinity of the cargo berth. The concrete of the track bed has been a subject to degradation as a result of many years of exploitation resulting, inter alia, in its cyclical flooding of petroleum products during the unloading and loading of rail tankers. Repairs carried out in the previous...
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The Influence of the Aircraft Operating Fluids on the Mechanical Parameters of the Airport Surface Concrete
PublikacjaThe authors of the article assessed the impact of operating fluids used to service aircraft on changing mechanical parameters of cement concrete intended for airport pavement. The research concerned concrete designed with the use of CEM I 42.5N LH NA low-alkali cement, broken granite aggregate, fine washed aggregate, and admixtures. The analysis included the assessment of changes in dierences in endurance parameters over various...
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Structural Assessment of Reinforced Concrete Beams Incorporating Waste Plastic Straws
PublikacjaThe behavior of reinforced concrete beams containing fibers made of waste plastic straws (WPSs) under the three point bending test is examined. The effect of WPS fiber addition on the compressive and split tensile strength is reported. Four concrete mixes were prepared. The control mix PS-0 had a proportion of 1 cement: 1 sand: 2 coarse aggregate and a water cement ratio of 0.4. In the other three mixes PS-0.5, PS-1.5 and PS-3,...
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Effect of coarse grain aggregate on strength parameters of two-stage concrete
Publikacja. Two-stage concrete (TSC) is a special type of concrete that the method of its construction and implementation is different from conventional one. In TSC, coarse aggregate particles are first placed in the formwork and voids between them are subsequently injected with a special cementations mixture. TSC has been successfully used in many applications, such as underwater construction, casting concrete sections congested with reinforcement...
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Guided Wave Propagation in Detection of Partial Circumferential Debonding in Concrete Structures
PublikacjaThe following article presents results of investigating the damage detection in reinforced concrete beams with artificially introduced debonding between the rod and cover, using a non-destructive method based on elastic waves propagation. The primary aim of the research was to analyze the possible use of guided waves in partial circumferential debonding detection. Guided waves were excited and registered in reinforced concrete...
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Debonding Detection in Reinforced Concrete Beams with the Use of Guided Wave Propagation
PublikacjaOne of the most frequent damage of the reinforced concrete structures is debonding between steel bar and concrete cover. In the case of debonding occurrence not only the strength of the structure decreases, but also it is more vulnerable to corrosion damages. For this reason fast and effective methods of debonding detection in an early stage of its development need a significant boost. The paper presents analytical and experimental...
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Safety assessment of a concrete viaduct damaged by vehicle impact and an evaluation of the repair
PublikacjaDamage to lower parts of viaducts caused by impact from under-passing high vehicles is relatively frequent. One such incident, in which a viaduct was damaged by the impact from a truck with an improperly assembled hydraulic crane, is considered in this work. The analysis is based on a detailed object damage evaluation, 3D laser scanning, and numerical simulations. The aim of the study is to accurately model the vehicle impact into...
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BEHAVIOR OF REINFORCED CONCRETE BEAMS CONTAINING LIGHTWEIGHT AGGREGATE IN THE TENSILE ZONE
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The use of GFRP tubes as load-bearing jackets in concrete-composite columns
PublikacjaThe paper presents the fields of applications of polymer composites in building structures. The use of composite glass fibre tubes is discussed in more detail. The laboratory methods used to test the mechanical properties of these pipes are presented. An original research program is presented, including six concrete-filled glass fibre tubes. The cylinders and columns made in this way were tested for their axial load capacity. Conclusions...
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Application of Artificial Neural Networks to Predict Insulation Properties of Lightweight Concrete
PublikacjaPredicting the properties of concrete before its design and application process allows for refining and optimizing its composition. However, the properties of lightweight concrete are much harder to predict than those of normal weight concrete, especially if the forecast concerns the insulating properties of concrete with artificial lightweight aggregate (LWA). It is possible to use porous aggregates and precisely modify the composition...
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Model-Based Adaptive Machine Learning Approach in Concrete Mix Design
PublikacjaConcrete mix design is one of the most critical issues in concrete technology. This process aims to create a concrete mix which helps deliver concrete with desired features and quality. Contemporary requirements for concrete concern not only its structural properties, but also increasingly its production process and environmental friendliness, forcing concrete producers to use both chemically and technologically complex concrete...
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Evaluation of reinforcement corrosion rate in concrete structures by electrochemical noise measurements
PublikacjaW pracy przedstawiono wyniki obliczeń rezystancji polaryzacyjnej w układzie złożonym z dwóch elektrod (ze stali węglowej oraz elektrody odniesienia), umieszczonych w otulinie betonowej. Szybkość korozji ulega zmianom uzależnionym od stopnia nasiąknięcia betonu roztworem zawierającym jony chlorkowe. Zmiany rezystancji polaryzacyjnej elektrody stalowej oceniane są na podstawie pomiarów prądowego i potencjałowego szumu elektrochemicznego....
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FE-modelling of strain localization in concrete with coupled elasto-plasticity and damage
PublikacjaW artykule przedstawiono wyniki numerycznej dla zginania belki betonowej przy zastosowaniu modelu sprężysto-plastycznego, modelu z degradacja sztywności i modelu połączonego sprężysto-plastycznego z degradacją sztywności. Wszystkie modele rozszerzono o długość charakterystyczną mikrostruktury za pomocą teorii nielokalnej.
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Multi-scale modelling of concrete beams subjected to three-point bending
PublikacjaW artykule przedstawiono wyniki numeryczne MES dwuskalowego modelowania belek betonowych z nacięciem na poziomie skali makro i mezo. Obliczenia wykonano przy wykorzystaniu modelu degradacji sztywności z nielokalnym osłabieniem. Beton został opisany na poziomie skali mezo jako stochastyczny materiał 3-składnikowy złożony z kruszywa, zaczynu cementowego oraz stref kontaktu. Natomiast na poziomie skali makro został opisany jako materiał...
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Investigations of size effect in tensile fracture of concrete using a lattice model
PublikacjaArtykuł przedstawia symulacje efektu skali w betonie podczas rozciągania przy zastosowaniu nowego modelu siatkowego. Zbadano wpływ rozkładu i wielkości kruszywa oraz wpływ strefy kontaktu na efekt skali.
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J. FE modelling of cracks in concrete elements within continuum mechanics.
PublikacjaW artykule przedstawiono wyniki symulacji rys zakrzywionych w elementach betonowych w warunkach mieszanego sposobu obciążenia. Symulacje wykonano przy zastosowaniu 3 różnych modeli: modelu sprężysto-plastycznego, modelu w ramach mechaniki zniszczeniowej i modelu z rysami obracającymi się.
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Modeling of capillary fluid flow in concrete using a DEM-CFD approach
PublikacjaSformułowano połączone podejście do modelowania dwufazowego przepływu wody napędzanego hydraulicznie i kapilarnie w nienasyconym betonie. Proces przepływu analizowano numerycznie w mezoskali w warunkach dwuwymiarowych (2D), łącząc metodę elementów dyskretnych (DEM) z obliczeniową dynamiką płynów (CFD) w warunkach izotermicznych. Przeprowadzono w pełni sprzężone hydromechaniczne testy symulacyjne na małych próbkach betonu o uproszczonej...
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Experimental investigations of size effect in reinforced concrete beams failing by shear
PublikacjaW artykule omówiono wyniki doświadczalne efektu skali w zbrojonych betonowych belkach niszczących się przez ścinanie. Doświadczenia wykonano dla belek o różnych wymiarach ze zbrojeniem stalowym i bazaltowym. Podczas doświadczeń pomierzono siłę oraz szerokości lokalizacji i rys. Wyniki porównano z modelem skali wg Bazanta.
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Application of DIC technique to concrete - study on objectivity of measured surface displacements
PublikacjaArtykuł omawia wyniki pomiarów szerokości lokalizacji odkształceń na powierzchni betonu podczas zginania belek. Wykonano obszerne studia nad obiektywnością pomierzonych przemieszczeń w betonie. Opracowano własna metodę do obliczeń szerokości lokalizacji.
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Early prediction of macrocrack location in concrete and other granular composite materials
PublikacjaHeterogeniczne kruche kompozyty, takie jak beton, ceramika i skały składają się z ziaren połączonych wiązaniami. Pytanie, czy ścieżka pęknięcia, która prowadzi do zniszczenia może być przewidziania na podstawie znanych cech mikrostrukturalnych, a mianowicie łączności wiązań, rozmiaru, energii pękania, wytrzymałości pozostają otwarte. Istnieje wiele kryteriów pęknięć. Najczęściej używane są oparte na postulowanym ekstremum naprężenia...
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Numerical analysis of behaviour of reinforced concrete elements under eccentric compression
PublikacjaPrzedstawiono wyniki modelowania nośności elementów żelbetowych stosując metodę elementów skończonych. Do opisu betonu zastosowano sprężysto-plastyczne prawo materiałowe wg Druckera-Pragera. Do modelowania stali zbrojeniowej zastosowano sprężysto-plastyczne prawo materiałowe według von Misesa. Obliczenia wykonano dla ścian żelbetowych.
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A Non-local elasto-plastic model to describe localisations of deformation in concrete
PublikacjaPrzedstawiono wyniki numerycznej symulacji lokalizacji odkształceń stosując metodę elementów skończonych na bazie nielokalnego prawa sprężysto-plastycznego dla betonu. Prawo wykorzystuje długość charakterystyczną. Obliczenia dla ściskania jednoosiowego pokazały, że wyniki numeryczne nie zależą od siatki MES. Osiągnięto pełną regularyzację problemu brzegowego.
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Patryk Ziółkowski dr inż.
OsobyAbsolwent Wydziału Inżynierii Lądowej i Środowiska Politechniki Gdańskiej, w specjalności Konstrukcje Budowlane i Inżynierskie. Pracuje na stanowisku adiunkta w Katedrze Konstrukcji Inżynierskich. Brał udział w projektach międzynarodowych, w tym projektach dla Ministerstwa Transportu stanu Alabama (2015), jest także laureatem grantu Fundacji Kościuszkowskiej na prowadzanie badań w USA, który zrealizował w 2018 roku. Współautor...
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Maximum temperature of 0.5-W infrared laser-Illuminated gold nanorod platforms
Dane BadawczeData concern a system consisted of two pieces of borosilicate glass surrounded by air and joined together by a transparent glue, which is to serve as a thermal transducer. On the top and bottom sides of the smaller piece, gold nanorods are dislocated. Glass is prepared here due to its high transparency, facilitating heat to be produced within the system....
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Dawid Ryś dr hab. inż.
OsobySZKOLENIA Szkolenie dotyczące metodyki zarządzania projektami PRINCE 2. Certyfikat kwalifikacji. Szkolenie dotyczące Mikromechaniki Pracy Mieszanek Mineralno-Asfaltowych Szkolenie doyczące interakcji koło pojazdu-nawierzchnia
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Adiabatic calorimetry results for fresh concrete mixes M0 and M100
Dane BadawczeAdiabatic calorimetry results for fresh 3D printed concrete mixes (M0 and M100) determined using Controls S.p.A., Italy calorimeter
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Wave propagation signals for ultrasonic tomography of concrete during splitting
Dane BadawczeThe DataSet contains the results of the mechanical behaviour of a concrete cube with dimensions 70 x 70 x 70 cm3under the splitting test. Three cubes were tested: cube 1 (concrete with polymer fibres), cube 2 (concrete with steel fibres) and cube 3 (plain concrete).
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Investigation of Durability Properties for Lightweight Structural Concrete with Hemp Shives Instead of Aggregate
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The influence of texturing of the surface of concrete substrate on its adhesion to cement mortar overlay
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