bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of FTIR ATR method to examine the polymer content in the modified bitumen and to assess susceptibility of bitumen to ageing
Authors: Zofka Adam , Maliszewska Dominika , Maliszewski Maciej , Boratyński Jacek
Published: July 2024

The infrared spectroscopy is suitable for the assessment of chemical compounds based on the plots of light intensity as a function of wavelength within the infrared range of electromagnetic spectrum. It enables the fingerprinting of substances, as well as detection and quantitative analysis of admixtures and additives present in a given substance. In case of bitumen binders the FTIR method may be adopted for the assessment of presence of ageing products. It effectively identifies impurities and discloses the presence of additives, e.g. adhesion agents. The FTIR device is also used for checking the presence of polymers in bitumen and even for determining the modification degree through an appropriate quantitative assessment. The present paper outlines practical applications of FTIR to testing bitumens, which include assessment of several types of binders prepared under control conditions, i.e. with a known polymer concentration and ageing degree. For comparison purposes, some commercial bitumens available on the Polish market and currently used for road pavement construction, have also been examined.
Properties of steel in railway bridge constructed in 1887
Authors: Hołowaty Janusz , Wichtowski Bernard
Published: July 2024

A number of 19th century steel railroad bridges are still in operation. Mechanical and metallurgical properties of steel in such bridges, and also its durability, have not been sufficiently studied, and these can vary considerably. This paper presents the results of analysis of mechanical parameters as well as the method used to determine the design strength of a plate girder railway bridge, which has been in operation for almost 130 years. The tests were carried out on the structural steel samples cut from dismounted floor stringers in end-of-life condition due to extensive corrosion. The grade and quality of the structural steel were determined and used in the design of the bridge repair project in order to keep it in operation. The method of steel evaluation as presented in this paper can be applied in other repairs and retrofitting of old railway bridges.
The Mycenaean bridges - technical evaluation trial
Authors: Karaś Sławomir , Kowal Maciej
Published: July 2024

Under this project two Mycenaean bridges, both located near the village of Arkadiko in Peloponnese (Greece), were examined through a field survey. These bridges, believed to be one of the oldest preserved bridges in the world, are part of the cultural heritage of humanity. This paper presents the results of a basic static analysis with identification of the weak points of the structure, which are the consequence of its transformation from the original corbelling system to a mixed corbelling and arch system. It seems to be accidental but indispensable according to principles of engineering mechanics.
Analysis of permanent deformations in granular materials of road structures
Authors: Aleksandrov Anatoliy Sergeevich , Semenova Tatiana Victorovna , Aleksandrova Nataliya Pavlovna
Published: July 2024

Models of permanent deformation in soils and granular materials are analysed in the article. Power, logarithmic and exponential functions that connect permanent deformation with the deformation caused by the first loading or with the one accumulated as a result of a certain number of load applications are found to be most often used. Due to the application of a hereditary creep theory some generalizing models for the analysis of permanent deformations under cyclic loading were obtained. As a result, a new method based on the integration of power functions describing the increment of permanent deformation was proposed. The experimental data on the dependence of residual deformation upon the amount of loads, maximum and minimum stresses were obtained, coefficients of equations derived were defined. The results of the calculations and the experimental data of a triaxial test of sand-gravel mix and granodiorite crushed stone were compared.
The influence of cyclic loading on the static strength of cement-bound sand – qualitative analysis
Authors: Brzeziński Karol , Adamczewski Grzegorz , Tutka Paweł
Published: July 2024

The main purpose of the paper is to evaluate the effect of cyclic loading on the static bending strength Rb of cement-bound sand (CBS). The mixture contained graded standard quartz sand bound with cement added at a proportion of 10% of the weight of sand. The main part of the experimental research were three-point bending tests performed on rectangular specimens. The specimens were subjected to cyclic pre-loading with different numbers of cycles and different bending force values. Strength tests were then conducted on pre-loaded specimens and the results were compared with non-preloaded specimens. ANOVA statistical analysis method was applied to the comparison of average strengths. This revealed an increase of static strength for specific cyclic pre-loading conditions. The influence of the number of pre-loading cycles and of the bending force value on the strength of specimens was checked as the next step.
Strengthening of steel structures with CFRP strips
Authors: Kowal Maciej , Łagoda Marek
Published: July 2024

The paper presents the results of research on the suitability of externally bonded composite strips of carbon fibre-reinforced polymer (CFRP) for post-strengthening of steel structures. Specimens with the strips applied on both sides (double cover joints) were prepared and subjected to axial tension tests to find which of the eight different configurations of end detailing provides the strongest bond. The strengthening effect of externally bonded composite strips was tested on sixteen steel I-beams, including determination of the effective bond length and the effects of the thickness of adhesive layer and modulus of the CFRP strip on the load capacity of the steel-adhesive-CFRP strip assembly. The research showed that externally adhered CFRP strips can increase the bending strength of steel structures (an 8% increase was obtained in the experiments) and the shape of spew fillet can have a significant influence on the strength of the strengthened system (the difference reaching up to 57%).
Classification of the modernized DMS-65 folded bridge structure according to STANAG 2021 requirements
Authors: Chmielewski Ryszard , Wolniewicz Andrzej
Published: July 2024

The paper attempts to establish procedures connected to the application of STANAG 2021 ENRG standardization agreement requirements in order to determine the load-bearing capacity of the DMS-65 folded bridge, which is part of the equipment inventory of the Polish Army. Giving the selected span constructions of a folded bridge their corresponding military classification numbers, in accordance with the STANAG 2021 requirements, provides an indication of their applicability in NATO military operations. Hypothetical vehicles of MLC class 50, 60, 70 and 80 were chosen as the load in order to classify the selected construction variants according to the specified procedure. The structure's utility features, such as platform width, were seen as a limitation in the selection of loading class in relation to the structure of a span.
Defining the domain and boundary conditions for finite element model of flexible road pavement
Authors: Nagórski Roman , Tutka Paweł , Złotowska Magdalena
Published: July 2024

The paper presents three methods for defining a finite cylindrical-type domain for finite element analysis of an elastic multi-layered half-space subjected to a rotationally symmetric vertical load distributed over a circular area, thus providing a mechanistic model of a flexible road pavement. For three sets of boundary conditions the methods ensure the consistency between the maximum deflection and the exact calculated value for a multi-layered half-space with compromising the accuracy of the key strain values. The first case uses standard support conditions at the finite element model boundaries – fixed in the direction perpendicular to that plane and sliding in the tangential direction. The other two cases use half-infinite elements – at the base and at the side wall of the domain. The first method, as an additional benefit, enables determining the exact value of the maximum deflection of pavement that can be used in the second and in the third of the described methods.
Lightweight concrete bridge deck slabs reinforced with GFRP composite bars
Authors: Wiater Agnieszka , Siwowski Tomasz
Published: July 2024

The durability of typical reinforced concrete bridge deck slabs is several times shorter than the durability of the main girders or other basic elements of bridges. This is due to ever-increasing traffic loads and the aggressiveness of the environment, which is intensified by the need for winter maintenance of bridges. Over the past several years, numerous technological, material and construction solutions have been developed in order to extend the technical life of the deck slabs of bridge structures. These include, among others, the use of lightweight concrete and also reinforcements made of composite bars. By combining these two materials into lightweight concrete slabs that are reinforced with GFRP composites, it is possible to obtain a synergy of high strength and durability of GFRP composite and also a reduction of the self-weight of a bridge. The paper presents an overview of the applications of lightweight concrete and GFRP composite bars in the deck slabs of bridge structures. Limited research on this constructional solution, which was completed with its first national implementation on a road bridge, was also presented. Moreover, the directions of further studies, which are necessary to develop the design principles that would enable wider use of this type of bridge deck slabs, were also provided.
Evaluation of skid resistance of exposed aggregate concrete pavement in the initial exploitation period
Authors: Wasilewska Marta , Gardziejczyk Władysław , Gierasimiuk Paweł
Published: July 2024

The paper presents the evaluation of skid resistance of pavements in their early life on the basis of macrotexture and microtexture changes determined with the Circular Texture Meter (CTM) and the Dynamic Friction Tester (DFT). Tests were performed on two test pavement sections made from exposed aggregate concrete on S8 expressway located in Poland. The relevant parameters, namely the Mean Profile Depth MPD and the friction coefficient DFT20 were measured after two and six weeks from pavement construction and then after three and sixteen months of traffic loads. No changes to the macrotexture were observed in these periods. However, significant changes were observed in the microtexture. The lowest values of DFT20 were determined two weeks from paving, indicating the effect of increased slipperiness just after placement. This lower initial friction coefficient DFT20 can be attributed to the presence of curing agent residue. Such residues are gradually removed from the pavement surface by weathering and trafficking and then the value of DFT20 stabilizes and stays constant at a certain level. The coefficient of friction decreased by ca. 20% in the period between the third and the sixteenth month of trafficking. Finally, the results of evaluation were compared with the classification system developed in the U.S., based on the International Friction Index IFI.
Pavement deterioration model based on GPR datasets
Authors: Batrakova Angelika G. , Batrakov Dmitry O. , Antyufeyeva Mariya S.
Published: July 2024

The paper deals with monitoring the current condition of flexible road pavement involving GPR technology. The methodology of using GPR is formed on remote measurements of thickness and permeability of pavement structural layers. After primary processing of GPR data they are interpreted by means of the developed algorithms and software. Then these data are used to build models of road section deterioration. Dynamic adaptive models are proposed in order to solve the problem of predicting the condition of individual local pavement segments. The mathematical apparatus of dynamic adaptive model of pavement deterioration was based not only on accounting the values of the explanatory variables at fixed times, but also on the rate and character of change of these variables. A comparative analysis carried out and the performance of the proposed models on the example of road sections of the Kharkiv region of Ukraine is shown.
Determination of load action ranges in static and dynamic tests of subgrades by applying rigid plates
Authors: Węgliński Szymon
Published: July 2024

Soil bearing capacity and compactness testing by rigid plates is commonly used during ground investigations and work quality control on most sites where enclosed and right-of-way structures are being built. Typically, the VSS (static plate bearing) test apparatus is used for this purpose. In recent years LFG falling weight deflectometers (dynamic plate load tests) have been increasingly used on building sites. This paper presents the theoretical bases relating to load testing by rigid plates. Several numerical calculations were made for selected soils, presenting the load distribution, corresponding to the range of the above tests in the subgrade. The type and state of soil as well as the applied load values have been confirmed to have a decisive bearing influence on the load action range. The assumption of the constant measuring range for static plate bearing tests (amounting to about 2-3 plate diameters) and for dynamic plate load tests has not been proved by the numerical calculations based on the theory of rigid foundations.
Influence of the construction technology on the texture and roughness of concrete pavements
Authors: Mackiewicz Piotr , Szydło Antoni , Krawczyk Bartłomiej
Published: July 2024

The paper presents studies of different ways of finishing the top surface of concrete pavements. The authors carried out investigations on selected concrete pavement stretches of motorways and expressways in Poland and analysed the variation in roughness and texture depending on the type of pavement structure and base, the temperature, the type of surface finish and the in-service time. It has been found that the construction technology and the type of pavement structure have a bearing on roughness while the top surface finish technology has an effect on texture. The highest pavement smoothness values were measured on the jointless continuously reinforced pavements. It is shown that the texture index considerably depends on the pavement service time. No effect of temperature on the investigated parameters was observed.
Pavement modelling using mechanical and thermal homogenization of layered systems
Authors: Graczyk Mirosław , Rafa Józef , Zofka Adam
Published: July 2024

The paper presents a model of the mechanical and thermal homogenization of the layered pavement system. The actual road/airport pavement consisting of several different layers resting on a sub-grade is modelled by a layer with dynamically and thermally equivalent physico-mechanical parameters. Using mass, wave, energy and thermodynamic criteria, equivalent models of the pavement in the homogenized system and in the multilayer system are presented. The modelling was conducted to obtain equivalence between the dynamic and thermal wave processes taking place in the multilayer system and in the homogenized system. The problem solution was constructed for a layer interacting with a half-space, modelling a layered pavement resting on a sub-grade (a half-space). The actual pavement was mathematically and physically modelled by the equivalent layer, taking into account the mechanical and thermal processes taking place in the latter. The presented solution enables one to carry out analyses of the universal problem of a layer resting on a sub-grade and to evaluate complex problems relating to the thermo-mechanics and condition testing of layered road and airport pavements.
Testing the load capacity of a soil-steel box structure
Authors: Machelski Czesław , Korusiewicz Leszek
Published: July 2024

The deformation of the circumferential section of a box culvert shell made of corrugated steel plates is analysed. Deflections and unit strains in selected shell points were adopted as the measure of the deformation of the corrugated steel shell. The quantities were measured using inductive displacement gauges and electric resistance strain gauges. The investigations were carried out in laboratory conditions under specifically selected configurations of a distributed load. Loading intensity, surcharge thickness and the area of load action on the surcharge were adopted as variable test parameters. The effectiveness of the interaction between a geo-grid and the soil in the surcharge in reducing the deformation of the shell was analysed.
The effect of nano-CaCO3 on the mechanical properties and permeability of roller compacted concrete pavement (RCCP)
Authors: HasaniNasab Shahab , Jebur Mohammad Hassan , Sharafi Hassan
Published: July 2024

The paper presents the investigations of the mechanical properties water absorption and porosity of the roller compacted concrete pavements (RCCP) with different amounts of nano-CaCO3. The nano-particles of CaCO3 were partially added to RCCP, and the mechanical properties of the specimens were measured. The results indicate that nano-CaCO3 can improve the compressive strength and the tensile splitting strength of RCCP. The nano-CaCO3 used up to 1% as a partial replacement for cement can accelerate the C-S-H gel formation at the early ages of hydration. This is due to increased crystalline Ca(OH)2 amount during the early ages of hydration. Increasing nano-CaCO3 content by more than 1% decreases the compressive and tensile splitting strength, and increases water absorption and permeability. The addition of CaCO3 nano-particles may increase C-S-H content, which improves the mechanical properties of concrete, fills the concrete pores, and decreases water absorption and permeable voids volume.
Analysis of a flexible road pavement on a subgrade with an inclusion in the form of a pipeline running along the road axis
Authors: Gajewska Beata , Gajewski Marcin , Kraszewski Cezary
Published: July 2024

The paper presents an analysis of a flexible road pavement with a concrete pipeline running along the road axis, just under the pavement. The subgrade of such a pavement cannot be regarded as homogenous and the design cannot be limited to merely the selection of a catalogue pavement structure or to the direct application of the mechanistic-empirical method. Additional analyses are necessary in order to evaluate whether the proposed road design will provide proper protection for the underground structures located in the subgrade. The problem is considered as three-dimensional and the analyses are carried out using the finite element method. The proposed design variants are evaluated and the solution recommended for considered case is indicated. Moreover, the results of parametric analyses of the selected variant, carried out to determine the influence of the backfill parameters on the deformation of the geosynthetic reinforcement in the road foundation and on the tensile stresses in the concrete pipe, are presented.
Heavy maintenance of concrete paved roads using the regional roads No. 102 and No. 142 as an example
Authors: Mieczkowski Paweł , Majer Stanisław , Budziński Bartosz
Published: July 2024

The paper describes heavy maintenance projects carried out on two regional roads located in the West Pomerania region of Poland. The projects started in 2017 on two sections of these roads. Completely different methods were used on these two sections. On the regional road No. 142 in-place crushing, specifically the rubblizing technique was used over an almost 20 km long stretch of pavement. In the second case the old pavement was left in place and a layer of bituminous-aggregate mixture was placed to control reflective cracking. Pros and cons of these methods are presented in the paper, together with the problems noted during the works.
Risk assessment of the use of corrugated metal sheets for construction of road soil-shell structures
Authors: Mistewicz Marek
Published: July 2024

The process of construction involves a risk of non-compliance of the construction works with the basic requirements of both Polish and European regulations. In order to mitigate the consequences of events related to the above-mentioned risk the products are subject to standardisation or technical evaluation prior to their placement on the market. The risk assessment methods are designed to identify the essential characteristics of construction products by analysing their effect on compliance of the construction works in which they are incorporated with the basic requirements. This article presents risk assessment related to incorporation in the works of a set of corrugated metal sheet products designed for construction of road bridges, overpasses and tunnels. An original qualitative method of risk assessment related to incorporation of a construction product in the works was conceived and its usefulness was confirmed. It has been demonstrated that while it is indispensable to carry out the risk assessment at the technical assessment stage, it is not, however, sufficient for efficient managing the risk of placing construction product on the market.
Analysis of flexible pavement performance prediction models based on structural behaviour
Authors: Paplauskas Paulius , Vaitkus Audrius , Kleizienë Rita
Published: July 2024

Sustainable and durable road pavement requires appropriate maintenance and repair strategies. National road authorities collect data describing pavement condition every several years and use specific life-cycle analysis methods to draw up priority plans for maintenance activities. The pavement performance models (PPMs) create a basis for the life-cycle and cost-benefit analysis as they help to evaluate pavement condition as well as to predict pavement deterioration. The objective of this research is analysing different PPMs of rut depth propagation and to compare predicted rut depth with measured during service of the road. Four PPMs were analysed during this research based on a traffic flow or construction age. The pavement performance prediction models were applied to predict the increment of rutting for eleven road sections based on their bearing capacity properties.
The assessment of stability at compression of steel pipes considering effects of uniform corrosion
Authors: Glinicka Aniela , Imiełowski Szymon
Published: July 2024

In aggressive environments structural steel components of engineering structures may become affected by corrosion. Even with corrosion protection, their critical load capacity and stability are seriously affected by the consequences of corrosion in aggressive environments due to impurities and possible failures. In this paper a critical state analysis of corroded struts is presented. The input data for the analysis was taken from laboratory corrosion tests in which steel pipes of a few different diameters were subjected to the attack of sulphuric and hydrochloric acids and placed in salt spray tester. The loss of material due to corrosion was determined and graphs, presenting the loss of material as a function of pipe diameter and the corrosion rate over time, were determined. The relative decrease of the maximum elastic strain energy which can be stored in the strut and the relative decrease of the critical load of elastic buckling were calculated for a series of corroded pipes. The curves of the relative change of the maximum elastic strain energy and the relative change of critical load over the time of corrosion progression were found to follow a similar path. For determining the critical load for a given strut, boundary conditions are taken into consideration. However, it is not necessary in the case of maximum elastic strain energy, which makes it a more convenient stability measure of the critical load capacity of strut.
Effect of various de-icers containing chloride ions on scaling resistance and chloride penetration depth of highway concrete
Authors: Reiterman Pavel , Keppert Martin
Published: July 2024

The use of chloride-based de-icers belongs to the most common road winter maintenance measures applied to prevent dangerous driving conditions. Chloride-based de-icers are the most frequently used worldwide. The essential difficulty with de-icers is their detrimental effect on concrete, other components of the road infrastructure and on vehicles. The interaction of various individual chloride salts with concrete is described in the paper; the experimental programme was focused on evaluation of the most frequently applied chloride-based de-icers in terms of damage to the air-entrained concrete used for highway construction. Three individual salts – NaCl, CaCl2, MgCl2 – and one blend (NaCl + CaCl2) were used. Their effect on concrete was investigated in terms of surface scaling during freezing-thawing cycles, residual mechanical properties and final ingress of chloride ions. Calcium chloride exhibited the most detrimental effect on the studied concrete.
Bentonite-loess slurry for construction of diaphragm walls and bored piles
Authors: Dreger Marcin , Przygoda Mieczysław , Kraszewski Cezary , Mitrut Michał , Rafalski Leszek , Wojdal Mariusz
Published: July 2024

Bentonite fluids are used in narrow excavations in technologies of slurry walls and bored piles. If bentonite is characterised by high liquid limit, production of support fluid with sufficiently high density and accompanying low viscosity is impossible. The aim of the presented research was to verify the usefulness of loess for modification of bentonite slurries. Various bentonite-loess mixtures and suspensions activated with sodium carbonate were tested. It was noted that an addition of loess results in a decrease in liquid limit of the bentonite-loess mixture. Testing of suspensions produced from different bentonite-loess mixtures enabled determination of the optimum sodium carbonate content as well as the minimum bentonite-loess mixture content in the suspension ensuring the required density. The influence of loess content on viscosity and water bleed was then investigated, which enabled determination of loess content range at which suspensions with the required density fulfil also the requirements regarding viscosity and bleed. It was ascertained that an addition of loess enables production of bentonite-loess slurries with adequate properties. Based on the presented results, a patent was obtained and production of bentonite-loess mixture for use in technology of slurry walls was initiated.
Multi-factor method of comparison of the geometrical condition of railway tracks on bridges and tests sections
Authors: Bałuch Henryk
Published: July 2024

The paper presents a method of comparing the geometrical condition of railway tracks at different times, in different places and with interdependent phenomena. This method involves treating the most important railway track properties as independent diagnostic variables and expressing each of them on a centile scale assumed as the basis for comparisons. The dependent variable is the geometric interval. In this way, it is possible to significantly enrich the description of the railway track condition on sections of railway lines on which changes in their state require a more detailed analysis, especially in terms of repair planning. Such sections are tracks on long bridges and sections on which new solution are tested. Selected track characteristic are obtained using diagnostics known in operation practice. The application of the method should facilitate planning of railway track repairs on bridges and comparison of results of experiments carried out on different test sections.
Recycling of cement kiln dust from cement plants to improve mechanical properties of road pavement base course
Authors: Ghrair Ayoup M. , Louzi Nawal
Published: July 2024

In the study, the potential of reuse of cement kiln dust (CKD) to improve the stability properties of the base course of road pavements was investigated. CKD was characterized chemically and physically. The results revealed that addition of CKD improved the mechanical properties of the base course significantly. The results showed a significant increase in California Bearing Ratio, from 234.5% measured for untreated base to 334.4%, 362.7% and 384.6% for CKD content of 5%, 15% and 25%, respectively. In terms of chemical composition, CKD is similar to cement. Scanning electron microscope images showed that the average particle size is approximately 0.5 microns. The granules are mainly spherically shaped, with cubic crystals of sodium and potassium salts. The leachability study of CKD in the base course revealed that heavy metal concentrations in CKD are fixed and insoluble in water.
Thermal shock as a cause of cracking of concrete in massive bridge support elements - a case study
Authors: Woyciechowski Piotr , Łukowski Paweł , Adamczewski Grzegorz
Published: July 2024

The paper presents an example of analysis of concrete cracking during construction of a massive bridge element, together with a demonstration of the expert diagnostic work aimed at a comprehensive assessment of the causes of crack development. The finite elements method analysis software FE-tool ConTeSt Pro was used. In the presented case there were typical doubts as to the reason of concrete cracking, and the performed analysis enabled identification of thermal shock as the primary cause of the observed distress. Finite element numerical simulations were adopted in order to analyze the temperature impact on crack development in the bridge elements. The complex case study analysis presented in the article may be treated as guidance on the use of scientific analysis methods in practical reinforced concrete cracking diagnostics. As a result of the work, thermal shock was identified to be the main reason for the damage of the massive bridge elements.
Deformacje smukłych elementów konstrukcji mostowej w zakresie dokrytycznym
Authors: Imiełowski Szymon
Published: July 2024

W pracy przedstawiono oryginalny model deformacji ściskanych prętów pryzmatycznych w zakresie dokrytycznym. Uwzględniono trzy pojawiające się sekwencyjnie etapy deformacji: skrócenie pręta o osi prostoliniowej, etap przejściowy (równoczesne odkształcenie postaciowe i wyboczenie pręta ściśliwego) oraz etap wyboczenia pręta o osi nieściśliwej. Kolejne etapy deformacji wyodrębniono na podstawie analizy wyników przeprowadzonego eksperymentu stateczności, w postaci wykresów zmian siły oraz składowych przemieszczenia, naprężenia i odkształcenia. Pojawienie się przemieszczenia poprzecznego pręta wyjaśniono jako skutek odkształcenia powstałego po osiągnięciu maksymalnej wartości energii odkształcenia postaciowego. Zweryfikowano kryterium utraty stateczności opisanej warunkiem maksymalnej energii odkształcenia sprężystego. Omówiono przypadek utraty stateczności prętów smukłych, które przenoszą siłę krytyczną, jak również prętów średnich smukłości, dla których stan graniczny jest określony warunkami przejścia do trzeciego etapu deformacji. W drugim z wymienionych przypadków utraty stateczności wyodrębniono smukłości, przy których występuje przeskok konfiguracji pręta oraz smukłości, przy których stan graniczny określony jest niestatecznością materiałową.
Próba określenia przepustowości relacji podporządkowanych w sytuacji zatłoczenia na jezdni głównej
Authors: Gasz Krzysztof
Published: July 2024

W artykule przedstawiono autorską metodę określenia przepustowości relacji podporządkowanych na skrzyżowaniu bez sygnalizacji,dołączających się na jezdni głównej do kolejki pojazdów spowodowanej działaniem sygnalizacji świetlnej na kolejnym skrzyżowaniu. Zaproponowany sposób obliczenia przepustowości tych relacji składa się z czterech etapów. Na początku obliczono długość pasa zwalnianą przez pojazdy opuszczające skrzyżowanie z sygnalizacją świetlną. W drugim etapie określono przepustowość relacji prawoskrętnej dołączającej się do kolejki pojazdów. W kolejnym kroku obliczono przepustowość relacji lewoskrętnej dołączającej się do kolejki pojazdów. Ostatni etap to obliczenie czasu blokowania skrzyżowania przez pojazdy poruszające się w kolejce.
Comparison of fracture parameters obtained from modified semi-circular bending (SCB) test
Authors: Vacková Pavla , Valentin Jan
Published: July 2024

For several years the crack propagation test data of asphalt mixtures according to CSN EN 12697-44 have been collected and evaluated at the Czech Technical University in Prague. Over time, the standardised test procedure has been adapted to better suit the conditions and practice typical of the Czech Republic – in terms of test specimen compaction, availability of cutting discs of suitable thickness, diameter of test specimens, loading speed etc. Modifications encompassed some of the test conditions as well as the procedures of data logging and subsequent evaluation of raw data. It has also been gradually established that the strict focus on fracture toughness, assumed by the European standard to be used as the only suitable qualitative parameter, is probably incorrect, or at least ineffective. The characteristics of fracture energy have been introduced and further studied.
Szacowanie aktualnego poziomu niezawodności konstrukcji istniejących mostów i wiaduktów kolejowych
Authors: Rakoczy Anna M. , Jivan-Coteti Aleksandra
Published: July 2024

Problem starzenia się mostów i wiaduktów kolejowych oraz ich degradacja stanowi ważne zagadnienie w większości krajów europejskich. Prognozowanie przydatności do użytkowania kolejowych obiektów inżynieryjnych, zaprojektowanych według schematów obciążenia obowiązujących w czasie ich projektowania, a użytkowanych obecnie w nowych warunkach eksploatacyjnych zwiększonego nacisku osi (do 25 ton/oś) i prędkości pociągów towarowych (do 120 km/h), jest istotne przy podejmowaniu decyzji eksploatacyjnych. Dlatego też, niezwykle ważne jest opracowanie algorytmu określającego poziom niezawodności konstrukcji nośnej istniejących (starzejących się) mostów oraz wiaduktów kolejowych w obecnych i w przyszłych warunkach eksploatacyjnych. Obecne procedury oceny mostów i wiaduktów kolejowych w zakresie dalszej ich eksploatacji nie uwzględniają zmienności obciążeń i parametrów nośności konstrukcji, co może prowadzić do błędnej oceny przydatności kolejowego obiektu inżynieryjnego do dalszego użytkowania. Celem artykułu jest przedstawienie metody probabilistycznej do oceny istniejących mostów i wiaduktów kolejowych w aspekcie ich dalszej eksploatacji. To podejście określa prawdopodobieństwo wystąpienia awarii (bezpieczeństwo) oraz ryzyko konsekwencji związanych z awarią.
Trwałość betonu nawierzchniowego wykonanego w warunkach laboratoryjnych i w skali budowy drogi ekspresowej
Authors: Kubissa Wojciech , Dąbrowski Mariusz , Chojnacki Bartłomiej , Glinicki Michał A.
Published: July 2024

W pracy przedstawiono badania doświadczalne właściwości betonu projektowanego na dolną warstwę nawierzchni drogowej. Porównano właściwości betonu dolnej warstwy w nawierzchni dwuwarstwowej z eksponowanym kruszywem, wbudowanego na odcinku próbnym drogi ekspresowej, z właściwościami betonu wykonanego w laboratorium z użyciem cementów typu CEM II/A-V i CEM II/A-S. Zakres badań objął mieszanki betonowe zawierające kruszywo granitowe i wapienne. Przeanalizowano podstawowe właściwości techniczne betonu: wytrzymałość na ściskanie i rozciąganie przy rozłupywaniu, charakterystykę porów powietrznych, mrozoodporność, szybkość absorpcji wody i głębokość penetracji jonów chlorkowych. Próbki laboratoryjne i próbki-odwierty z nawierzchni wykazały zbliżone właściwości mechaniczne i odporność na działanie cyklicznego zamrażania i rozmrażania. Stosowanie cementów portlandzkich z dodatkami mineralnymi nie pogorszyło mrozoodporności betonu pomimo zaobserwowanych zmian w charakterystyce porów. Stwierdzono zwiększenie do 19% wytrzymałości na ściskanie oraz zmniejszenie do 22% sorpcyjności betonu.
Stan zachowania kruszyw węglanowych w środowisku alkalicznym
Authors: Dubiniewicz Andrzej
Published: July 2024

W artykule przedstawiono ocenę stanu zachowania kruszyw budowlanych uzyskiwanych ze zróżnicowanych litologicznie skał węglanowych po 100 dniach ich zanurzenia w roztworze 1M NaOH w temperaturze pokojowej. W badanych kruszywach nie zaobserwowano przejawów reakcji alkalicznej w postaci dedolomityzacji ani śladów rozpuszczania krzemionki, uległy one natomiast spękaniom. W płaszczyznach bliźniaczych dolomitu znajdującego się w kruszywach dolosparytowych doszło do utlenienia minerałów nieprzezroczystych. Ustalono, że kruszywa pochodzące z kambryjskich zdolomityzowanych wapieni sparytowych, dewońskich dolomikrytów, dolosparytów, biomikrytów, zdolomityzowanych wapieni mikrytowych, karbońskich pelbiosparytów i jurajskich biomikrytów są chemicznie stabilne w środowisku alkalicznym.
Badania wpływu nierówności nawierzchni na zmiany nacisków osi pojazdów ciężkich z wykorzystaniem ugięciomierza TSD
Authors: Harasim Przemysław , Gajewski Marcin
Published: July 2024

W artykule przedstawiono wyniki badań zależności pomiędzy stanem technicznym nawierzchni, wyrażonym parametrem równości podłużnej IRI, a wynikającymi z niego zmianami nacisków osi pojazdów ciężkich. W tym celu wykorzystano wyniki pomiarów wykonanych ugięciomierzem laserowym TSD, który wśród mierzonych parametrów rejestruje m.in. profil podłużny nawierzchni oraz naciski osi pomiarowej. Na podstawie danych zgromadzonych podczas rutynowych pomiarów, wytypowano odcinki reprezentatywne do badań, a wyselekcjonowane dane poddano analizom statystycznym. Pod uwagę brano zarówno wyniki pomiarów równości jak i powiązane z nimi naciski osi pojazdu. Omówiono zagadnienie równości podłużnej w kontekście wymagań stawianym nawierzchniom drogowym, a także określono stopień korelacji wskaźnika IRI z zarejestrowanymi naciskami osi pojazdu pomiarowego. Określona została ilościowa ocena wpływu nierówności na wielkość nacisków pojazdów ciężkich, uzupełniona o analizę zmian trwałości nawierzchni asfaltowych opartą na uzyskanych danych.
Finite element and fatigue analysis of flexible pavements based on temperature profile modeling
Authors: Cho Seoyoung , Lakatos Éva
Published: July 2024

The effect of temperature on asphalt pavement structure is of great importance due to the nature of binder used in the asphalt layers. An equivalent temperature is commonly applied to eliminate the effect of temperature dependence in calculations of mechanical properties of the asphalt and of the pavement. Equivalent temperatures, applied as constant values, are supposed to have the same effect on fatigue behavior of the pavement in the period of one year as the real varying weather conditions. The aim of the presented research was to compare the behavior of the pavement under realistic temperature data throughout a single year with the results of the traditional pavement design method. Temperature data were obtained from a previously established weather station. Binder viscosity and asphalt dynamic modulus were defined based on the temperature profile for asphalt layers divided into 19 sublayers. This subdivision was introduced to better reflect the changes in strength characteristics of the asphalt layers along the depth of the structure. Comparison with the simple calculation using the equivalent temperature method showed that the detailed model outlined in this paper can provide better prediction of the overall pavement structural capacity. The focus of this study is to apply asphalt layer discretization to reflect temperature variation and its influence on changes in strength properties of asphalt mixtures. Temperature at each sublayer was estimated using the German specification, dynamic modulus was determined using the Witczak model, and the structural analysis was performed employing the finite element method.
Analiza przyczyn uszkodzeń jednowarstwowej betonowej nawierzchni drogi ekspresowej
Authors: Glinicki Michał A. , Jóźwiak-Niedźwiedzka Daria , Antolik Aneta , Dziedzic Kinga , Dąbrowski Mariusz , Bogusz Karolina , Lisowski Paweł
Published: July 2024

Po 15 latach eksploatacji odcinka drogi ekspresowej zaobserwowano przedwczesne uszkodzenia nawierzchni betonowej objawiające się widocznymi spękaniami, głównie wzdłuż szczelin poprzecznych oraz w narożach płyt. Na próbkach-odwiertach przeprowadzono badania diagnostyczne, obejmujące analizę petrograficzną betonu i kruszyw mineralnych przy użyciu mikroskopii optycznej i skaningowej, ocenę właściwości sprężystych, stopnia spękania i charakterystyki porów, a także identyfikację produktów reakcji alkalia-krzemionka. Stwierdzono liczne pęknięcia w ziarnach kruszywa grubego kwarcytowego oraz w matrycy cementowej. W ziarnach kwarcytu zidentyfikowano znaczącą obecność kwarcu mikrokrystalicznego i kryptokrystalicznego. Jednoznacznie zidentyfikowano produkty reakcji alkalia-krzemionka o typowym składzie. Znaczne spękanie i zmniejszenie modułu sprężystości skorelowano z obecnością reaktywnego kwarcu w kruszywie kwarcytowym, uznając reakcję alkalia-krzemionka za główną przyczynę uszkodzeń. Przedyskutowano możliwą rolę dodatkowych czynników destrukcyjnych, takich jak wpływ ruchu pojazdów ciężkich oraz agresji mrozu.
Ocena wpływu sposobu dozowania dodatku asfaltu naturalnego Gilsonite na właściwości mieszanki mineralno-asfaltowej
Authors: Bilski Marcin , Mielczarek Marta , Górnaś Przemysław , Słowik Mieczysław , Wojciechowska Patrycja
Published: July 2024

W pracy przedstawiono wyniki badań laboratoryjnych mieszanek mineralno-asfaltowych (MMA) typu beton asfaltowy, które zawierały w swoim składzie dodatek asfaltu naturalnego Gilsonite w ilości 4% w stosunku wagowym do masy asfaltu, dozowany dwiema metodami: „na mokro" lub „na sucho”. Zakres przeprowadzonych badań laboratoryjnych obejmował oznaczenie modułów sztywności w badaniach pośredniego rozciągania, modułów sztywności metodą pełzania pod obciążeniem statycznym oraz odporności na działanie wody i mrozu. Na podstawie analizy statystycznej otrzymanych wyników badań laboratoryjnych dokonano oceny istotności różnic w uzyskanych właściwościach MMA zawierających dodatek Gilsonite dozowany różnymi metodami, w porównaniu do wartości uzyskanych na mieszance referencyjnej. Ustalono, że metoda dozowania („na mokro" lub „na sucho") dodatku asfaltu naturalnego Gilsonite do analizowanej mieszanki mineralno-asfaltowej typu beton asfaltowy nie ma istotnego wpływu na wartości modułów sztywności oznaczonych metodą IT-CY, metodą pełzania, a także na wartości wskaźnika wytrzymałości na rozciąganie pośrednie ITSR.
Potencjalna reaktywność alkaliczna piasku z krajowych złóż
Authors: Jóźwiak-Niedźwiedzka Daria , Antolik Aneta , Dziedzic Kinga , Lisowski Paweł
Published: July 2024

Piasek stosowany jako kruszywo drobne w betonie w niekorzystnych warunkach środowiska może spowodować reakcję alkaliczno-krzemionkową, a w konsekwencji – pogorszenie właściwości użytkowych i trwałości betonu. Celem pracy jest porównanie reaktywności alkaliczno-krzemionkowej 18 piasków naturalnych o różnym pochodzeniu. Wykonano badania potencjalnej reaktywności piasku zgodnie z procedurami PB/1/18 i PB/3/18 przedstawionymi w Wytycznych Technicznych GDDKiA. Prze- prowadzono analizę składu mineralnego kruszywa pod kątem zawartości reaktywnych minerałów, badanie wydłużenia próbek zapraw oraz analizę mikroskopową produktów reakcji alkalia-krzemionka. W toku badań dowiedziono, że 6 kruszyw (33%) spośród 18 przebadanych należy zaklasyfikować do kategorii „umiarkowanie reaktywne”, natomiast 12 kruszyw (67%) należy przypisać do kategorii „niereaktywne”. Wykazano wpływ pochodzenia piasku na jego podatność na wystąpienie reakcji alkalicznej.
Resilience-based multi-objective optimization for determining the optimal sequence of bridge retrofit projects
Authors: Dezfuli Nezhad Mehdi , Raoufi Reza , Dalvand Ahmad
Published: July 2024

This study intends to provide a methodology for determination of the optimal sequence of bridge retrofit projects in the pre-disaster phase. A two-stage optimization model is proposed. In the first stage, single-objective optimization is used, and the weighted average number of reliable independent pathways (WIPW) is adopted as the measure of network resilience (MOR) to be maximized. In the second stage, multi-objective optimization is used, and two objective functions are introduced to be maximized: the measure of strategy implementation sequence (MOS) and the measure of strategy implementation time (MOT). The proposed methodology is illustrated using a hypothetical community road system. The results show that there is an inverse relationship between MOS and MOT. By considering these two new objectives in the process of pre-disaster risk mitigation planning, network owners can determine the trade-off between MOS and MOT and select a proper sequence of bridge retrofit projects based on predictability of the examined disruptive events.
Ocena przydatności destruktu asfaltowego do drogowych nawierzchni betonowych
Authors: Iwański Mateusz Marek , Linek Małgorzata , Nita Piotr , Piotrowska Patrycja , Remišová Eva
Published: July 2024

W artykule przedstawiono ocenę przydatności destruktu asfaltowego do zastosowania w składzie nawierzchniowej mieszanki betonowej. Omówiono wyniki parametrów 6 destruktów asfaltowych pozyskanych z nawierzchni komunikacyjnych i oceniono pod względem możliwości zastosowania do mieszanek przeznaczonych na nawierzchnie betonowe. Czynniki zewnętrzne, które w czasie użytkowania oddziaływały na nawierzchnię, mogą wpływać na starzenie spoiwa i powodować zmiany proporcji związków chemicznych w jego budowie wewnętrznej. Z uwagi na powyższe konieczne było analizowanie parametrów kruszywa pochodzącego z recyklingu nawierzchni i mieszanek mineralno-asfaltowych, szczególnie pod kątem tekstury, absorpcji wody, właściwości lepiszcza, a także charakterystyki powierzchni cząstek pokrytych lepiszczem asfaltowym. W artykule zaproponowano ponowne wykorzystanie destruktu asfaltowego pochodzącego z eksploatowanych nawierzchni komunikacyjnych w składzie mieszanek betonowych przeznaczonych do wbudowania w nawierzchnie drogowe. Omówiono wyniki podstawowych parametrów betonów z dodatkiem wytypowanych destruktów.
Wpływ spoiwa mieszanego na właściwości recyklowanej mieszanki mineralno-asfaltowej z asfaltem spienionym w aspekcie jej uziarnienia
Authors: Iwański Marek , Mazurek Grzegorz , Chomicz-Kowalska Anna , Buczyński Przemysław , Cholewińska Małgorzata , Iwański Mateusz Marek , Maciejewski Krzysztof , Ramiączek Piotr
Published: July 2024

Rozwój prac modernizacyjnych dróg różnych kategorii, od autostrad po drogi samorządowe, przyczynia się do powstawania dużej ilości destruktu asfaltowego (RAP) o zróżnicowanej jakości i uziarnieniu. W ramach gospodarki zrównoważonej niezbędne jest jego ponowne wykorzystanie. Obecnie w większości przeznaczony jest on do wytworzenia recyklowanych mieszanek mineralno-asfaltowych wbudowywanych w warstwę podbudowy. Zróżnicowana jakość destruktu wymaga zastosowania odpowiedniego rodzaju spoiwa, tak aby można było go wykorzystać w optymalny sposób. W związku z tym zaistniała potrzeba opracowania spoiwa hydraulicznego mieszanego, które składa się z cementu CEM I 32.R, wapna hydratyzowanego Ca(OH)2 oraz ubocznych cementowych produktów pylastych (UCPP) dobieranych w odpowiednich proporcjach. Badano wpływ składu spoiwa hydraulicznego mieszanego na następujące właściwości mieszanki wytwarzanej z zastosowaniem asfaltu spienionego: zawartość wolnych przestrzeni, wytrzymałość na pośrednie rozciąganie, wytrzymałość na osiowe ściskanie, odporność na oddziaływanie wilgoci i mrozu wg czterech różnych parametrów oraz moduł sztywności w temperaturze -10oC, +13oC, +25oC i +40oC wg metody IT-CY. Na podstawie wykonanych badań ustalono rekomendowany skład spoiwa zapewniający wymagane właściwości recyklowanej mieszanki związanej spoiwem hydraulicznym i asfaltem spienionym.