Arpad Čeh - Academia.edu (original) (raw)
Papers by Arpad Čeh
Journal of Faculty of Civil Engineering, 2024
Zbornik radova Građevinskog fakulteta, 2022
Insufficient representation of lightweight aggregate fiber reinforced concrete in technical regul... more Insufficient representation of lightweight aggregate fiber reinforced concrete in technical regulations is one of the main limiting factors for their wider application, despite the numerous advantages this material has over normal weight concrete. Based on a review of the available literature and current technical regulations, the paper presents existing proposals for stress-strain relationships in compression and tension for fiber reinforced concrete, with special focus to their applicability to lightweight aggregate concrete.
Journal of Faculty of Civil Engineering, 2024
Applied Sciences
Experimental and numerical research on axially compressed columns made from built-up two-chord co... more Experimental and numerical research on axially compressed columns made from built-up two-chord concrete-filled steel tubes (TCCFSTs) is presented in this study. The columns were constructed from two parallel circular high-strength steel tubes connected by five batten tubes. The chord tubes were filled with high-strength concrete. The yield stress of the steel used was 600 MPa, while the cylinder compressive strength of the concrete was 95 MPa. Hollow specimens were also tested to serve as a control group. An experimental analysis investigated the influence of the compressive strength of the concrete fill on the load-bearing capacity of the column and the influence of the concrete fill on the slenderness of the column. The behavior under load, stress and strain development, and the failure modes of the specimens were also analyzed. The results of the tests showed that all parts of the built-up column participated in the load-bearing process. The load-bearing capacity of the hollow tw...
Buildings
Quality assessment of stiffness and load-carrying capacity of composite connections is of great i... more Quality assessment of stiffness and load-carrying capacity of composite connections is of great importance when it comes to designing timber–concrete composite structures. The new European regulation intended explicitly for timber–concrete structures has made a significant contribution to this field, considering that until today there was no adequate design standard. Due to the proposed general expressions for determining the stiffness and load-carrying capacity of composite connections made with dowel-type fasteners, which are incapable of describing most of the commonly applied fasteners, engineering, and scientific practice remained deprived of a quality assessment of the essential mechanical properties of the connection. In order to overcome this problem, this paper proposes a numerical model of the connection suitable for determining the whole load–slip curve, allowing it to estimate the stiffness and load-carrying capacity of the connection. The model was developed by consider...
Earth construction has long tradition in our civilization with wide distribution in various ways ... more Earth construction has long tradition in our civilization with wide distribution in various ways and techniques of application. When combined with other natural materials it is the material for construction of comfortable space for people. Increased need for energy efficient houses actualizes this type of construction in modern conditions as a holistic solution for modern buildings. In addition to many uses of earth as a building material, rammed earth wall came to consideration since it allows us to observe most of the advantages and disadvantages of this type of construction. Finding solutions to remedy observed disadvantages will lead to improved construction of adobe, wattle-and-daub, unbaked bricks, etc. This paper is aimed at proving energy efficiency of rammed earth wall and it points out possible research directions into improvements while preserving existing benefits. The most important issue is preservation of cost efficiency of earth building while using other natural sup...
This article is about renewal of landslides, protection of slope failures and tunnel profiles wit... more This article is about renewal of landslides, protection of slope failures and tunnel profiles with lightweight composite concrete made with polystyrene. This concrete has several advantages over ordinary concretes arid mortars: it is lighter, it can be build in by concreting machines in thickness up to 50 mm. Coating made from this concrete is filtrating and protective and it is frost resistant, because the ice can be easily spread inside this material. Lightweight composite concrete made from polystyrene is easily processed: it can be drilled, cut, and grind, so it is easy to drill and concrete anchors or even plant trees for environment renewal. This concrete is permeable as well as the soil, so it is suitable for roots of trees. Lightweight composite concrete made from polystyrene can absorbs noise, so it is suitable for tunnels and slopes by the roads.
Archives for Technical Sciences, Jun 13, 2016
Thermal bridges have significant influence at calculation of the energy performance classes of bu... more Thermal bridges have significant influence at calculation of the energy performance classes of buildings. This especially applies to countries where energy performance classes of buildings are determined based only on energy consumption for heating (such as Serbia, Bosnia and Hercegovina, Croatia...). Significant differences arise in determining the heat losses due to thermal bridges. Differences that can occur by using simplified methods depending on national recommendations of different countries are shown in this article.
Tehnicki vjesnik - Technical Gazette, Feb 1, 2018
This paper presents an original contribution with assessment of the current state in exploitation... more This paper presents an original contribution with assessment of the current state in exploitation safety and usability of thin concrete domes of the beauteous Subotica Synagogue, built in 1902. The authors are analyzing the condition of the materials used in the Subotica Synagogue, on extracted samples of concrete and steel reinforcement with a binder which was used instead of cement, a gypsum-CaSO4×0,5H2O. The source of the problem, according to the author, is the lack of lime-Ca(OH)2 from the mixture of gypsum and pozzolanic aggregates made of baked clay. This is the main reason for poor concrete strength of only 7.6 MPa and the present significant corrosion processes in the steel reinforcement of that concrete, which far from the recommended values of pH ≥ 12, have a measured value of only pH = 7.55. These results advise a need for repair of the part of the building that has not been analyzed or investigated yet, partially due to difficult access and also apparently good condition, since cracks, larger deformation or collapse have not appeared yet. The condensation on the domes is damaging the painted decorations with gilding which is falling and reduces the exploitation safety and the mood of the visitors and believers, who came to the synagogue. The authors are proposing a method for rehabilitation of the vaults and ribs of the beautiful Subotica Synagogue domes by simultaneously satisfying the exploitation safety and avoiding the occurrence of condensation and damaging of the painted and gilded ceilings. We believe that the article will inspire and have a positive effect in the professional and scientific society so in other synagogues in Europe and around the world the exploitation usability of vaults will be inspected and if necessary, possible repairs can be made in the same or any similar way as proposed in this scientific work.
Journal of the Croatian Association of Civil Engineers, Oct 1, 2018
Nosivost na proboj ekscentrično opterećenih AB ravnih ploča bez posmične armature U radu je anali... more Nosivost na proboj ekscentrično opterećenih AB ravnih ploča bez posmične armature U radu je analiziran utjecaj momenta koji se prenosi spojem unutrašnjeg stupa i ploče, te utjecaj čvrstoće betona na nosivost ravne ploče na proboj. Sedam uzoraka u punoj veličini ispitano je eksperimentalno i numerički. Rezultati su prikazani u obliku krivulje opterećenje-rotacija ploče i uspoređeni s kriterijima loma prema teoriji kritične posmične pukotine (CSCT), kao i s približnim izrazima. Provedena je nelinearna analiza MKE uz kalibraciju modela s eksperimentalnim podacima radi boljega poklapanja numerički dobivenog odnosa opterećenje-rotacija s eksperimentalnim rezultatima.
Zbornik radova Građevinskog fakulteta, 2018
This article provides information about the possibilities and technologies [2] available for the ... more This article provides information about the possibilities and technologies [2] available for the building industry in the Republic of Serbia, and concerns the trendswhich expansion is expected in Europe and worldwide-the of use of renewable sources of building materials. Exploitation of sand and gravel from rivers and dry mines in many EU countries is prohibited. Excavation of clay from clay deposits and blasting the rock mass are considered as a violation of the natural environment and resulting with scars on our planet Earth.Renewable sources of construction materials are considered materials which each year can be renewed and which are the most common by-product of agricultural production.Materials obtained by recycling existing materials already used in construction, as well as by-products of industrial production are also considered sustainable materials.Renewable materials are supporting the new, worldwide trend in building industry, called "Green Building" with the aim of reducing harmful CO2 emissions.This paper will discuss renewable materials obtained as a by-product of agricultural production such as grain straw (wheat, barley, rye and oats), cane and hemp shiv obtained by mechanical breakingof hemp stems.These materials are cheap because they are by-products and they are energy efficient, which is particularly important nowadays.The construction of buildings with the above mentioned materials should be well planned to ensure the durability, fire resistance and particularly the pleasant and comfortable stay for the people.The walls made of this material must be solved, and ensured to avoid occurrence of rodents and other pests that may be carriers of dangerous and contagious diseases.
Periodica Polytechnica Civil Engineering, 2016
In this paper a new rheological-dynamical continuum damage model for concrete under compression i... more In this paper a new rheological-dynamical continuum damage model for concrete under compression is used to research the behaviour of reinforced concrete beams subjected to bending. Within the framework of this approach the stress-strain curve of a concrete under compression in the pre-peak regime can be computed if the compressive strength, elastic modulus, concrete density and Poisson's ratio are experimentally evaluated. The ultimate strain is determined in the post-peak regime only, using the secant stress-strain relation from damage mechanics. Experimental stress-strain data in the pre-peak regime for five concrete compositions were obtained during the examination presented herein. The numerical predictions regarding moment-curvature and ductility of a reinforced concrete beam are presented for five concrete compositions, demonstrating capabilities of a new analytical model.
2011 IEEE 3rd International Symposium on Exploitation of Renewable Energy Sources (EXPRES), 2011
Original scientific paper This article describes the possibilities in using recycled, ground expa... more Original scientific paper This article describes the possibilities in using recycled, ground expanded polystyrene (EPS) as aggregate for lightweight concretes as thermal insulation or as a structural concrete. The article presents a rich experience and provides explanation on the benefits of using ground EPS aggregate compared to virgin EPS beads in making lightweight concrete. A reinforced lightweight concrete structure made by SU-styrol – technology is also presented. Although the compressive strength of this lightweight aggregate concrete is six times less than that of ordinary concrete, the deformation (deflection) and the loadbearing capacity of the reinforced slab and that of the Su-styrene reinforced concrete and of the ordinary reinforced concrete slab are the same, which is very interesting. The authors have provided a physical interpretation of this behaviour, with the conclusion that the reinforced SU-styrol lightweight concrete is compatible with steel, unlike ordinary c...
Mechanics of Time-Dependent Materials
An improved analytical model based on rheological-dynamical analogy (RDA) is briefly explained an... more An improved analytical model based on rheological-dynamical analogy (RDA) is briefly explained and used for the analysis of concrete cylinders under compression. The approach involves standard mechanical properties such as compressive strength, elastic modulus, concrete density and Poisson’s ratio for the prediction of both the ascending and the descending branch of the stress–strain curve. Our own experimental data for arbitrarily selected high strength concrete with high deformability was analyzed. Further, the validity of the RDA model is checked against tests of other authors for one normal concrete and for six recycled aggregate concrete mixtures. To demonstrate the capabilities of the improved model, using analytically established stress–strain relations for analyzed samples, the moment-curvature relations and ductility of reinforced concrete beams in bending were numerically examined. The analysis showed that the ductile behavior of beams made of concrete with recycled aggregate can be achieved by limiting the reinforcement ratio to 0.01 if the recycled concrete aggregate is used and to 0.02 for recycled brick aggregate.
Zbornik radova Građevinskog fakulteta
Zbornik radova Građevinskog fakulteta
Zbornik radova Građevinskog fakulteta, 2016
Zbornik radova Građevinskog fakulteta, 2016
Zbornik radova Građevinskog fakulteta, 2015
Journal of Faculty of Civil Engineering, 2024
Zbornik radova Građevinskog fakulteta, 2022
Insufficient representation of lightweight aggregate fiber reinforced concrete in technical regul... more Insufficient representation of lightweight aggregate fiber reinforced concrete in technical regulations is one of the main limiting factors for their wider application, despite the numerous advantages this material has over normal weight concrete. Based on a review of the available literature and current technical regulations, the paper presents existing proposals for stress-strain relationships in compression and tension for fiber reinforced concrete, with special focus to their applicability to lightweight aggregate concrete.
Journal of Faculty of Civil Engineering, 2024
Applied Sciences
Experimental and numerical research on axially compressed columns made from built-up two-chord co... more Experimental and numerical research on axially compressed columns made from built-up two-chord concrete-filled steel tubes (TCCFSTs) is presented in this study. The columns were constructed from two parallel circular high-strength steel tubes connected by five batten tubes. The chord tubes were filled with high-strength concrete. The yield stress of the steel used was 600 MPa, while the cylinder compressive strength of the concrete was 95 MPa. Hollow specimens were also tested to serve as a control group. An experimental analysis investigated the influence of the compressive strength of the concrete fill on the load-bearing capacity of the column and the influence of the concrete fill on the slenderness of the column. The behavior under load, stress and strain development, and the failure modes of the specimens were also analyzed. The results of the tests showed that all parts of the built-up column participated in the load-bearing process. The load-bearing capacity of the hollow tw...
Buildings
Quality assessment of stiffness and load-carrying capacity of composite connections is of great i... more Quality assessment of stiffness and load-carrying capacity of composite connections is of great importance when it comes to designing timber–concrete composite structures. The new European regulation intended explicitly for timber–concrete structures has made a significant contribution to this field, considering that until today there was no adequate design standard. Due to the proposed general expressions for determining the stiffness and load-carrying capacity of composite connections made with dowel-type fasteners, which are incapable of describing most of the commonly applied fasteners, engineering, and scientific practice remained deprived of a quality assessment of the essential mechanical properties of the connection. In order to overcome this problem, this paper proposes a numerical model of the connection suitable for determining the whole load–slip curve, allowing it to estimate the stiffness and load-carrying capacity of the connection. The model was developed by consider...
Earth construction has long tradition in our civilization with wide distribution in various ways ... more Earth construction has long tradition in our civilization with wide distribution in various ways and techniques of application. When combined with other natural materials it is the material for construction of comfortable space for people. Increased need for energy efficient houses actualizes this type of construction in modern conditions as a holistic solution for modern buildings. In addition to many uses of earth as a building material, rammed earth wall came to consideration since it allows us to observe most of the advantages and disadvantages of this type of construction. Finding solutions to remedy observed disadvantages will lead to improved construction of adobe, wattle-and-daub, unbaked bricks, etc. This paper is aimed at proving energy efficiency of rammed earth wall and it points out possible research directions into improvements while preserving existing benefits. The most important issue is preservation of cost efficiency of earth building while using other natural sup...
This article is about renewal of landslides, protection of slope failures and tunnel profiles wit... more This article is about renewal of landslides, protection of slope failures and tunnel profiles with lightweight composite concrete made with polystyrene. This concrete has several advantages over ordinary concretes arid mortars: it is lighter, it can be build in by concreting machines in thickness up to 50 mm. Coating made from this concrete is filtrating and protective and it is frost resistant, because the ice can be easily spread inside this material. Lightweight composite concrete made from polystyrene is easily processed: it can be drilled, cut, and grind, so it is easy to drill and concrete anchors or even plant trees for environment renewal. This concrete is permeable as well as the soil, so it is suitable for roots of trees. Lightweight composite concrete made from polystyrene can absorbs noise, so it is suitable for tunnels and slopes by the roads.
Archives for Technical Sciences, Jun 13, 2016
Thermal bridges have significant influence at calculation of the energy performance classes of bu... more Thermal bridges have significant influence at calculation of the energy performance classes of buildings. This especially applies to countries where energy performance classes of buildings are determined based only on energy consumption for heating (such as Serbia, Bosnia and Hercegovina, Croatia...). Significant differences arise in determining the heat losses due to thermal bridges. Differences that can occur by using simplified methods depending on national recommendations of different countries are shown in this article.
Tehnicki vjesnik - Technical Gazette, Feb 1, 2018
This paper presents an original contribution with assessment of the current state in exploitation... more This paper presents an original contribution with assessment of the current state in exploitation safety and usability of thin concrete domes of the beauteous Subotica Synagogue, built in 1902. The authors are analyzing the condition of the materials used in the Subotica Synagogue, on extracted samples of concrete and steel reinforcement with a binder which was used instead of cement, a gypsum-CaSO4×0,5H2O. The source of the problem, according to the author, is the lack of lime-Ca(OH)2 from the mixture of gypsum and pozzolanic aggregates made of baked clay. This is the main reason for poor concrete strength of only 7.6 MPa and the present significant corrosion processes in the steel reinforcement of that concrete, which far from the recommended values of pH ≥ 12, have a measured value of only pH = 7.55. These results advise a need for repair of the part of the building that has not been analyzed or investigated yet, partially due to difficult access and also apparently good condition, since cracks, larger deformation or collapse have not appeared yet. The condensation on the domes is damaging the painted decorations with gilding which is falling and reduces the exploitation safety and the mood of the visitors and believers, who came to the synagogue. The authors are proposing a method for rehabilitation of the vaults and ribs of the beautiful Subotica Synagogue domes by simultaneously satisfying the exploitation safety and avoiding the occurrence of condensation and damaging of the painted and gilded ceilings. We believe that the article will inspire and have a positive effect in the professional and scientific society so in other synagogues in Europe and around the world the exploitation usability of vaults will be inspected and if necessary, possible repairs can be made in the same or any similar way as proposed in this scientific work.
Journal of the Croatian Association of Civil Engineers, Oct 1, 2018
Nosivost na proboj ekscentrično opterećenih AB ravnih ploča bez posmične armature U radu je anali... more Nosivost na proboj ekscentrično opterećenih AB ravnih ploča bez posmične armature U radu je analiziran utjecaj momenta koji se prenosi spojem unutrašnjeg stupa i ploče, te utjecaj čvrstoće betona na nosivost ravne ploče na proboj. Sedam uzoraka u punoj veličini ispitano je eksperimentalno i numerički. Rezultati su prikazani u obliku krivulje opterećenje-rotacija ploče i uspoređeni s kriterijima loma prema teoriji kritične posmične pukotine (CSCT), kao i s približnim izrazima. Provedena je nelinearna analiza MKE uz kalibraciju modela s eksperimentalnim podacima radi boljega poklapanja numerički dobivenog odnosa opterećenje-rotacija s eksperimentalnim rezultatima.
Zbornik radova Građevinskog fakulteta, 2018
This article provides information about the possibilities and technologies [2] available for the ... more This article provides information about the possibilities and technologies [2] available for the building industry in the Republic of Serbia, and concerns the trendswhich expansion is expected in Europe and worldwide-the of use of renewable sources of building materials. Exploitation of sand and gravel from rivers and dry mines in many EU countries is prohibited. Excavation of clay from clay deposits and blasting the rock mass are considered as a violation of the natural environment and resulting with scars on our planet Earth.Renewable sources of construction materials are considered materials which each year can be renewed and which are the most common by-product of agricultural production.Materials obtained by recycling existing materials already used in construction, as well as by-products of industrial production are also considered sustainable materials.Renewable materials are supporting the new, worldwide trend in building industry, called "Green Building" with the aim of reducing harmful CO2 emissions.This paper will discuss renewable materials obtained as a by-product of agricultural production such as grain straw (wheat, barley, rye and oats), cane and hemp shiv obtained by mechanical breakingof hemp stems.These materials are cheap because they are by-products and they are energy efficient, which is particularly important nowadays.The construction of buildings with the above mentioned materials should be well planned to ensure the durability, fire resistance and particularly the pleasant and comfortable stay for the people.The walls made of this material must be solved, and ensured to avoid occurrence of rodents and other pests that may be carriers of dangerous and contagious diseases.
Periodica Polytechnica Civil Engineering, 2016
In this paper a new rheological-dynamical continuum damage model for concrete under compression i... more In this paper a new rheological-dynamical continuum damage model for concrete under compression is used to research the behaviour of reinforced concrete beams subjected to bending. Within the framework of this approach the stress-strain curve of a concrete under compression in the pre-peak regime can be computed if the compressive strength, elastic modulus, concrete density and Poisson's ratio are experimentally evaluated. The ultimate strain is determined in the post-peak regime only, using the secant stress-strain relation from damage mechanics. Experimental stress-strain data in the pre-peak regime for five concrete compositions were obtained during the examination presented herein. The numerical predictions regarding moment-curvature and ductility of a reinforced concrete beam are presented for five concrete compositions, demonstrating capabilities of a new analytical model.
2011 IEEE 3rd International Symposium on Exploitation of Renewable Energy Sources (EXPRES), 2011
Original scientific paper This article describes the possibilities in using recycled, ground expa... more Original scientific paper This article describes the possibilities in using recycled, ground expanded polystyrene (EPS) as aggregate for lightweight concretes as thermal insulation or as a structural concrete. The article presents a rich experience and provides explanation on the benefits of using ground EPS aggregate compared to virgin EPS beads in making lightweight concrete. A reinforced lightweight concrete structure made by SU-styrol – technology is also presented. Although the compressive strength of this lightweight aggregate concrete is six times less than that of ordinary concrete, the deformation (deflection) and the loadbearing capacity of the reinforced slab and that of the Su-styrene reinforced concrete and of the ordinary reinforced concrete slab are the same, which is very interesting. The authors have provided a physical interpretation of this behaviour, with the conclusion that the reinforced SU-styrol lightweight concrete is compatible with steel, unlike ordinary c...
Mechanics of Time-Dependent Materials
An improved analytical model based on rheological-dynamical analogy (RDA) is briefly explained an... more An improved analytical model based on rheological-dynamical analogy (RDA) is briefly explained and used for the analysis of concrete cylinders under compression. The approach involves standard mechanical properties such as compressive strength, elastic modulus, concrete density and Poisson’s ratio for the prediction of both the ascending and the descending branch of the stress–strain curve. Our own experimental data for arbitrarily selected high strength concrete with high deformability was analyzed. Further, the validity of the RDA model is checked against tests of other authors for one normal concrete and for six recycled aggregate concrete mixtures. To demonstrate the capabilities of the improved model, using analytically established stress–strain relations for analyzed samples, the moment-curvature relations and ductility of reinforced concrete beams in bending were numerically examined. The analysis showed that the ductile behavior of beams made of concrete with recycled aggregate can be achieved by limiting the reinforcement ratio to 0.01 if the recycled concrete aggregate is used and to 0.02 for recycled brick aggregate.
Zbornik radova Građevinskog fakulteta
Zbornik radova Građevinskog fakulteta
Zbornik radova Građevinskog fakulteta, 2016
Zbornik radova Građevinskog fakulteta, 2016
Zbornik radova Građevinskog fakulteta, 2015