Csaba Toth

Dr. Csaba Toth

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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 October 2020 in Sustainability
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RSRéka Szpotowicz
Réka Szpotowicz
CTCsaba Toth
Csaba Toth
There are a number of sustainable and environmentally friendly techniques and methods currently available in the construction industry. To promote sustainable development, different rating and certificating systems that evaluate the level of sustainability during the development of infrastructure construction projects have been developed. The aim of the research presented in this paper was to examine the applicability of sustainability rating systems in Hungary and find the most suitable option. After a review of commonly used rating systems, i.e., Greenroads, GreenLITES, I-LAST, Envision, and INVEST, the most suitable existing rating system is selected with the help of the Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) mathematical decision analysis method. This was achieved by utilizing 12 categories of input data (weights) analyzed through TOPSIS. The input data (weights) of the TOPSIS method were determined by a small research group of industry experts and academic professionals based on Hungarian practices and methodology. As a result of the calculation, the study found that the Envision rating system satisfies the criteria best, closely followed by Greenroads.

25 February 2022 in Applied Sciences
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TKTamás Király
Tamás Király
PPPéter Primusz
Péter Primusz
CTCsaba Toth
Csaba Toth
The aim of this research study was to analyse the approaches for establishing a spatial model of a radial truck tyre, based on the finite element method, in order to perform a realistic analysis of static as well as dynamic tyre–pavement interactions. A complex rubber tyre model having a large number of elements was formulated combining current state-of-the-art modelling techniques and, from that model, a simplified model having a smaller number of elements was derived. The complex model proved to be useful only for static loading, because of its high computational demand, while the simplified model proved to be also suitable for dynamic modelling. The two tyre models having different numbers of elements were compared by analysing the contact areas and stresses. Our results indicate that the basic idea of not changing material characteristics while simplifying the model, rebuilding only the carcass using composite shell elements, did not prove to be a satisfactory direction. The results given by the simplified model do not describe the behaviour of the radial tyre well but, rather, describe the behaviour of the diagonal tyre, regarding contact areas and stresses. On the contrary, when analysing stresses and strains in the road pavement structure, the two finite element models provided similar results in practice. Based on our comparison calculations, applying the average contact pressure q at analysis points at a 5–8 cm depth, the contact behaviour of the finite element tyre model can be used in any elastic-layer theory-based software.

10 December 2022 in Coatings
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CTCsaba Toth
Csaba Toth
PPPéter Primusz
Péter Primusz
Falling weight deflectometers (FWD) are utilised worldwide to analyse the condition and the load-bearing capacity of road pavement structures. One of the FWD measurement results, the deflection bowl, may provide surplus information that is suitable for better road pavement structure diagnostics, based on the novel approach presented in this paper. This study presents a computational method that can calculate the layer thicknesses from the deflection data recorded by the non-destructive FWD device. The motivation for this research is that FWD and GPR equipment are often not available at the same time. However, the back-calculation of the pavement layer moduli from the deflections requires knowledge of the exact thicknesses. The developed method is based on the inertia point principle and provides not only the total pavement thickness but also the total asphalt thickness at each FWD drop point. From 25,200 linear elastic layered pavement models, 350 virtual inertia points could be identified. To describe the relationship between the structural model characteristics of the pavement (thickness and subgrade modulus) and the virtual inertia points, we chose the Gaussian process regression, a widely used method in machine learning. In addition to the thicknesses, the point of inertia can also be used to calculate the bearing modulus of the subgrade with high accuracy. Based on the data from the experimental road section, the radius value of the inertia point rc is not sensitive to the stiffness of the layers that compose the pavement structure, depending only on the total pavement thickness and the bearing capacity of the subgrade. The calculation was compared with the AASHTO (1993) procedure, and very similar values for the subgrade-bearing capacity were obtained. Moreover, in the near future, the method can be further developed to provide an estimation of layer thicknesses, together with a deflection measurement, especially adapted to continuous deflection measurement devices (Curviameter and Rolling Wheel Deflectometer).

21 November 2024 in Pure and Applied Geophysics
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Enas AbdelsameiEnas Abdelsamei
Enas Abdelsamei
Diaa SheishahDiaa Sheishah
Diaa Sheishah
BRBoglárka Runa
Boglárka Runa
OBOlivér Balogh
Olivér Balogh
CTCsaba Toth
Csaba Toth
György SiposGyörgy Sipos
György Sipos
Ground penetrating radar (GPR) has been widely used to assess asphalt and pavement, especially in quality testing for newly constructed roads. However, its usage has been limited in regard to aged roads. Thus, this study focuses on the applicability of GPR to extract diverse information regarding structure, thickness, and various conditions, including the moisture content of an aged road section that has undergone repeated renewals. First, two methods were employed to calculate the thickness and dielectric values; the reflection amplitude and ground truth methods. The analysis was done by RADAN 7 software. Based on the findings, the average error of thickness on the same day between continuous GPR and the core data were 2.87% and 8.72%, respectively. Second, dielectric analysis of three structural units was performed under different moisture conditions. As a result, the average dielectric values of macadam (3, 3.3, and 4), surface asphalt layer (4, 7.06, and 8.31), and cement-treated base (4.83, 10.88, and 11.88) were determined under dry, medium-wet, and wet conditions, respectively. The volumetric water difference (f) within the pavement was also estimated. As for the asphalt, macadam, and cement-treated base, the difference in the volume fraction of water (f) was 0.06, 0.01, and 0.1, respectively, under dry and wet conditions, and 0.04, 0.004, and 0.09, respectively, under dry and medium-wet conditions. Overall, the findings demonstrate that reasonably accurate assessments of the pavement thickness, structure, dielectric values, and amplitude of aged roads can be achieved by using a GPR survey under various conditions.

5 January 2023 in Materials
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PPPéter Primusz
Péter Primusz
CTCsaba Toth
Csaba Toth
Dynamic modulus master curves are usually constructed by using sigmoid functions, but the coefficients of these functions are not independent of each other. For this reason, it is not possible to clearly identify their physical mean. Another way of describing the dynamic modulus master curves is to choose the Ramberg-Osgood (RAMBO) material model, which is also well-suited for modelling the cyclic behaviour of soils. The Ramberg-Osgood model coefficients are completely independent of each other, so the evaluation of the fitted curve is simple and straightforward. This paper deals with the application of the Ramberg-Osgood material model compared to the usual techniques for constructing a master curve, determining the accuracy in describing the material behaviour of asphalt mixtures, and seeking any surplus information that cannot be derived by traditional techniques. Because the dynamic modulus and phase angle master curves are strictly related, in the present study, the asymmetric bell-shaped frequency curve of Toranzos was used to describe the phase angle for four types of asphalt mixtures (RmB, PmB, RA, and NB). The results show that the RAMBO model is a good alternative to the sigmoid function in describing the master curve of the dynamic modulus. We successfully used the Toranzos asymmetric bell-shaped frequency curve to describe the phase angle master curve. We also found a promising relationship between the independent RAMBO model parameters and the physical properties of the investigated binders, but this requires further research.

1 January 2022 in Geographica Pannonica
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Diaa SheishahDiaa Sheishah
Diaa Sheishah
György SiposGyörgy Sipos
György Sipos
AHAlexandru Hegyi
Alexandru Hegyi
Peter KozakPeter Kozak
Peter Kozak
Enas AbdelsameiEnas Abdelsamei
Enas Abdelsamei
DPDávid Gergely Páll
Dávid Gergely Páll
Levees are earth structures constructed along alluvial rivers and are considered to be one of the essential components of flood risk and natural hazard reduction. The preservation of their condition would require orderly monitoring. In Hungary, an over 4200 km long levee system was constructed from the 19th century on. Since then, many natural and anthropogenic processes, such as compaction, erosion, subsidence etc., could contribute to the slow but steady deformation of these structures. In the meantime , due to the lack of documentation, their structure and internal composition are still unclear in many sections. The present study uses different geophysical techniques to validate their efficiency in detecting the structure, composition and potential defects along a 3.6 km levee section of the Lower Tisza River, affected significantly by seepage and piping phenomena during floods. Measurements were made using Ground Penetrating Radar (GPR), Electrical Resistivity Tomography (ERT) and drillings. Information obtained by the different techniques was cross-checked and combined. This way, the potential of the applied survey strategy could be demonstrated, and the selected levee section could be assessed in terms of its structure and composition. Consequently, the major reasons for frequently occurring adverse flood phenomena at the site could be revealed. The survey approach outlined in the present paper can be applied extensively along lowland levee systems in the region and elsewhere.