The first reason why concrete is a very useful material in construction is because of its density... more The first reason why concrete is a very useful material in construction is because of its density and strength. However, they tend to crack and require constant fixing, and this is usually expensive and tiresome. This research aims to investigate the feasibility of employing sodium alginate, a naturally occurring polysaccharide, as an encapsulated self-healing system for concrete. When sodium alginate is applied on concrete, it interacts with the calcium ions in the concrete to create a calcium alginate gel which helps to close up any cracks and also increases the durability of the concrete. The study embraced the usage of sodium alginate, rapeseed oil, calcium chloride, and water hydrate, which were blended with the IKA T25 harmonisation machine. The outcomes of the experiments indicate that self-healing concrete based on sodium alginate has higher durability, and the need for repairs is minimised; thus, the use of sodium alginate in new construction can be considered a promising direction.
The paper is concerned with a numerical homogenization technique for determination of effective m... more The paper is concerned with a numerical homogenization technique for determination of effective material properties of brick masonry in the elastic range. The homogenization problem is posed in the plane state of stress. The corresponding boundary value problem on a representative cell is discretized by the finite element method. The quadrilateral finite element with four nodes and eight degrees of freedom is applied and our own computer program is developed. The homogenization technique allows one to determine for masonry, which is an inhomogeneous two-phase composite medium, an equivalent homogeneous orthotropic material characterized by five material constants. The homogenized material constants can further be used in an analysis of large-scale masonry structures. The obtained results of numerical simulations are compared with predictions of the value of elastic modulus for masonry by other researches, and qualitative agreement can be observed.
Most Lecha w Poznaniu to nazwa obiektu skladającego sie z dwoch niezaleznych, dopelniających sie ... more Most Lecha w Poznaniu to nazwa obiektu skladającego sie z dwoch niezaleznych, dopelniających sie ale pobudowanych w roznych okresach czasu mostow drogowych ─ polnocnego i poludniowego ─ nad rzeką Wartą w ciągu ulic Lechickiej i Baltyckiej. Polnocny Most Lecha jest obecnie w trakcie gruntownej przebudowy (rys. 1, 2). Praca zawiera najwazniejsze informacje związane z obecną przebudową Mostu Lecha, dotyczące m.in. historii obiektu oraz jego znaczenia w ukladzie komunikacyjnym i rozwiązan konstrukcyjnych. Projekt przebudowy Mostu Lecha obejmuje calkowitą rozbiorke istniejącego od 1953 roku mostu, budowe nowego stalowo-betonowego mostu zespolonego w tej samej lokalizacji oraz dostosowanie dojazdow (rys. 1). Obecnie budowany most zaprojektowano jako trojprzeslowy ustroj belkowy o calkowitej dlugości 235,40 m. Najdluzsze jest przeslo środkowe o rozpietości 100,80 m, a przesla skrajne po 66,90 m. Calkowita szerokośc mostu wynosi 16,90 m, w tym ściezka pieszo-rowerowa o szerokości 3,70 m. Wysokośc konstrukcyjna przesel jest zmienna i wynosi 3,16 m w cześci środkowej, a na podporze 4,83 m. Projekt uwzglednia wszelkie ograniczenia wynikające z Decyzji o Środowiskowych Uwarunkowaniach, dlatego zrezygnowano z podpor w nurcie rzeki. Dzieki temu, po uporządkowaniu otoczenia mostu i rzeki, zmiany bedą korzystne takze dla zeglugi. Glownym zalozeniem projektowym nowego mostu jest poprawa podstawowych charakterystyk geometrycznych mostu i dostosowanie nowej konstrukcji do wyzszej klasy obciązen A wg normy PN-85/S-10030. Charakterystyczne parametry techniczne mostu zapewniają zwiekszenie liczby pasow ruchu z dwoch do trzech dla kazdego kierunku. Pomost budowanego mostu jest w konstrukcji stalowej zlozonej z czterech belek dwuteowych polączonych ze sobą poprzecznicami. Na konstrukcji tej bedzie wykonana plyta wspolpracująca z betonu C35/45, polączona z dźwigarami glownymi za pomocą sworzni zgrzewanych.
Foundations of Civil and Environmental Engineering, 2004
A variational formulation of the inequality problem of a plate resting on a foundation is develop... more A variational formulation of the inequality problem of a plate resting on a foundation is developed. The unilateral interaction conditions between the plate and its foundation are taken into account. For the plate the kinematical model of Reissner- Mindlin is applied and the elastoplastic material behaviour is assumed. The foundation is modelled as an elastoplastic medium of Winkler type. These fundamental assumptions impose inequality constraints on some quantities describing the plate-foundation system and, on the mathematical side, lead to an unilateral boundary value problem. We present a unified approach to this problem in which both the conditions of unilateral contact and those of elastoplastic behaviour are governed by variational inequalities. The proposed variational formulation consists of a variational equation and three variational inequali- ties. The finite element solution to the weak formulation is defined and numerical results for some test examples are presented.
The work is concerned with the determination of effective material parameters of reactive powder ... more The work is concerned with the determination of effective material parameters of reactive powder concrete (RPC) in the range of its nonlinear response. We have used a two-scale modelling technique and carried out a series of experimental tests which allow us to validate the proposed numerical model of the considered RPC concrete. The behavior of a RPC concrete on a macro scale is described on the basis of phenomena occurring in the microstructure of material. The material microstructure is taken into account by means of a representative volume element (RVE), the structure of which is generated in a stochastic way with data from the designed recipes of RPC. It is assumed that the microstructure of RPC is composed of isotropic linear elastic—(perfectly) brittle constituents and at the macro scale the material is homogenized. This approach is a good basis for a simple modelling of microcracks that cause the nonlinear behaviour of the material at the macro level. The numerical analysis is carried out here for the plane stress state problem, and at each level of analysis the finite element method is applied.
... 165 Tadeusz Burczynski, Michał Bereta, Arkadiusz Poteralski, Mirosław Szczepanik Bioinspired ... more ... 165 Tadeusz Burczynski, Michał Bereta, Arkadiusz Poteralski, Mirosław Szczepanik Bioinspired Algorithms in Multiscale Optimization..... 183 Wacław Kus, Tadeusz Burczynski Sensor Network Design for SpatioTemporal Prediction of Distributed Parameter Systems ...
The first reason why concrete is a very useful material in construction is because of its density... more The first reason why concrete is a very useful material in construction is because of its density and strength. However, they tend to crack and require constant fixing, and this is usually expensive and tiresome. This research aims to investigate the feasibility of employing sodium alginate, a naturally occurring polysaccharide, as an encapsulated self-healing system for concrete. When sodium alginate is applied on concrete, it interacts with the calcium ions in the concrete to create a calcium alginate gel which helps to close up any cracks and also increases the durability of the concrete. The study embraced the usage of sodium alginate, rapeseed oil, calcium chloride, and water hydrate, which were blended with the IKA T25 harmonisation machine. The outcomes of the experiments indicate that self-healing concrete based on sodium alginate has higher durability, and the need for repairs is minimised; thus, the use of sodium alginate in new construction can be considered a promising direction.
The paper is concerned with a numerical homogenization technique for determination of effective m... more The paper is concerned with a numerical homogenization technique for determination of effective material properties of brick masonry in the elastic range. The homogenization problem is posed in the plane state of stress. The corresponding boundary value problem on a representative cell is discretized by the finite element method. The quadrilateral finite element with four nodes and eight degrees of freedom is applied and our own computer program is developed. The homogenization technique allows one to determine for masonry, which is an inhomogeneous two-phase composite medium, an equivalent homogeneous orthotropic material characterized by five material constants. The homogenized material constants can further be used in an analysis of large-scale masonry structures. The obtained results of numerical simulations are compared with predictions of the value of elastic modulus for masonry by other researches, and qualitative agreement can be observed.
Most Lecha w Poznaniu to nazwa obiektu skladającego sie z dwoch niezaleznych, dopelniających sie ... more Most Lecha w Poznaniu to nazwa obiektu skladającego sie z dwoch niezaleznych, dopelniających sie ale pobudowanych w roznych okresach czasu mostow drogowych ─ polnocnego i poludniowego ─ nad rzeką Wartą w ciągu ulic Lechickiej i Baltyckiej. Polnocny Most Lecha jest obecnie w trakcie gruntownej przebudowy (rys. 1, 2). Praca zawiera najwazniejsze informacje związane z obecną przebudową Mostu Lecha, dotyczące m.in. historii obiektu oraz jego znaczenia w ukladzie komunikacyjnym i rozwiązan konstrukcyjnych. Projekt przebudowy Mostu Lecha obejmuje calkowitą rozbiorke istniejącego od 1953 roku mostu, budowe nowego stalowo-betonowego mostu zespolonego w tej samej lokalizacji oraz dostosowanie dojazdow (rys. 1). Obecnie budowany most zaprojektowano jako trojprzeslowy ustroj belkowy o calkowitej dlugości 235,40 m. Najdluzsze jest przeslo środkowe o rozpietości 100,80 m, a przesla skrajne po 66,90 m. Calkowita szerokośc mostu wynosi 16,90 m, w tym ściezka pieszo-rowerowa o szerokości 3,70 m. Wysokośc konstrukcyjna przesel jest zmienna i wynosi 3,16 m w cześci środkowej, a na podporze 4,83 m. Projekt uwzglednia wszelkie ograniczenia wynikające z Decyzji o Środowiskowych Uwarunkowaniach, dlatego zrezygnowano z podpor w nurcie rzeki. Dzieki temu, po uporządkowaniu otoczenia mostu i rzeki, zmiany bedą korzystne takze dla zeglugi. Glownym zalozeniem projektowym nowego mostu jest poprawa podstawowych charakterystyk geometrycznych mostu i dostosowanie nowej konstrukcji do wyzszej klasy obciązen A wg normy PN-85/S-10030. Charakterystyczne parametry techniczne mostu zapewniają zwiekszenie liczby pasow ruchu z dwoch do trzech dla kazdego kierunku. Pomost budowanego mostu jest w konstrukcji stalowej zlozonej z czterech belek dwuteowych polączonych ze sobą poprzecznicami. Na konstrukcji tej bedzie wykonana plyta wspolpracująca z betonu C35/45, polączona z dźwigarami glownymi za pomocą sworzni zgrzewanych.
Foundations of Civil and Environmental Engineering, 2004
A variational formulation of the inequality problem of a plate resting on a foundation is develop... more A variational formulation of the inequality problem of a plate resting on a foundation is developed. The unilateral interaction conditions between the plate and its foundation are taken into account. For the plate the kinematical model of Reissner- Mindlin is applied and the elastoplastic material behaviour is assumed. The foundation is modelled as an elastoplastic medium of Winkler type. These fundamental assumptions impose inequality constraints on some quantities describing the plate-foundation system and, on the mathematical side, lead to an unilateral boundary value problem. We present a unified approach to this problem in which both the conditions of unilateral contact and those of elastoplastic behaviour are governed by variational inequalities. The proposed variational formulation consists of a variational equation and three variational inequali- ties. The finite element solution to the weak formulation is defined and numerical results for some test examples are presented.
The work is concerned with the determination of effective material parameters of reactive powder ... more The work is concerned with the determination of effective material parameters of reactive powder concrete (RPC) in the range of its nonlinear response. We have used a two-scale modelling technique and carried out a series of experimental tests which allow us to validate the proposed numerical model of the considered RPC concrete. The behavior of a RPC concrete on a macro scale is described on the basis of phenomena occurring in the microstructure of material. The material microstructure is taken into account by means of a representative volume element (RVE), the structure of which is generated in a stochastic way with data from the designed recipes of RPC. It is assumed that the microstructure of RPC is composed of isotropic linear elastic—(perfectly) brittle constituents and at the macro scale the material is homogenized. This approach is a good basis for a simple modelling of microcracks that cause the nonlinear behaviour of the material at the macro level. The numerical analysis is carried out here for the plane stress state problem, and at each level of analysis the finite element method is applied.
... 165 Tadeusz Burczynski, Michał Bereta, Arkadiusz Poteralski, Mirosław Szczepanik Bioinspired ... more ... 165 Tadeusz Burczynski, Michał Bereta, Arkadiusz Poteralski, Mirosław Szczepanik Bioinspired Algorithms in Multiscale Optimization..... 183 Wacław Kus, Tadeusz Burczynski Sensor Network Design for SpatioTemporal Prediction of Distributed Parameter Systems ...
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