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Abstract

The paper discusses the reasons for the current trend of substituting ductile iron castings by aluminum alloys castings. However, it has been shown that ductile iron is superior to aluminum alloys in many applications. In particular it has been demonstrated that is possible to produce thin wall wheel rim made of ductile iron without the development of chills, cold laps or misruns. In addition it has been shown that thin wall wheel rim made of ductile iron can have the same weight, and better mechanical properties, than their substitutes made of aluminum alloys.

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Authors and Affiliations

M. Górny
E. Fraś
W. Kapturkiewicz
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Abstract

The paper presents results of metallographic examination of faults occurring in the course of founding thin-walled cast-iron castings in

furan resin sand molds. A non-conformance of the scab type was Observed on surface of the casting as well as sand buckles and cold

shots. Studied the chemical composition by means of a scanning electron microscope in a region of casting defects: microanalysis point

and microanalysis surface. Around the observed defects discloses high concentration of oxides of iron, manganese and silicon.

A computer simulation of the casting process has been carried out with the objective to establish the cause of occurrence of cold shots on

casting surface. The simulation was carried out with the use of NovaFlow & Solid program. We analyzed the flowing metal in the mold

cavity. The main reason for the occurrence of casting defects on the surface of the casting was gating system, which caused turbulent flow

of metal with a distinctive splash stream of liquid alloy.

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Authors and Affiliations

A.W. Orłowicz
A. Trytek
M. Tupaj
M. Mróz
O. Markowska
G. Bąk
T. Abram
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Abstract

The paper is a presentation of a study on issues concerning degradation of protective paint coat having an adverse impact on aesthetic

qualities of thin-walled cast-iron castings fabricated in furan resin sand. Microscopic examination and microanalyses of chemistry

indicated that under the coat of paint covering the surface of a thin-walled casting, layers of oxides could be found presence of which can

be most probably attributed to careless cleaning of the casting surface before the paint application process, as well as corrosion pits

evidencing existence of damp residues under the paint layers contributing to creation of corrosion micro-cells

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Authors and Affiliations

A. Trytek
M. Tupaj
M. Mróz
A.W. Orłowicz
G. Bąk
T. Abram
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Abstract

The excellent property combination of thin wall ductile iron castings (TWDI), including thin wall alloyed cast iron (e.g. austenitic TWDI) has opened new horizons for cast iron to replace steel castings and forgings in many engineering applications with considerable cost benefits. TWDI is considered as a potential material for the preparation of light castings with good mechanical and utility properties, the cost of which is relatively low. In this study, unalloyed and high Ni-alloyed (25% Ni) spheroidal graphite cast iron, with an austenitic metallic matrix were investigated. The research was conducted for thin-walled iron castings with 2, 3 and 5mm wall thickness, using different mould temperature (20°C, and 160°C) to achieve various cooling rates. The metallographic examinations i.e. characteristic of graphite nodules, metallic matrix, and primary grains of austenite dendrites (in high-nickel NTWDI) and mechanical properties were investigated. The study shows that homogeneity of the casting structure of thin-walled castings varies when changing the wall thickness and mould temperature. Finally, mechanical properties of thin-walled ductile iron castings with ferritic-pearlitic and austenitic metallic matrix have been shown.

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Authors and Affiliations

M. Górny
M. Kawalec
G. Witek
A. Rejek
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Abstract

The authors present a numerical study of a start-up of a boiler with a thick-walled element subjected to thermomechanical loading. The significance of calculations of real heat transfer coefficients has been demonstrated. Fluid dynamics, mechanical transient thermal and static structural calculations have been conducted in both separate and coupled modes. Strain-stress analyses prove that the effect of the heat transfer coefficient changing in time and place in comparison with a constant one as recommended by standards is the key factor of fatigue calculations.

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Authors and Affiliations

Krzysztof Wacławiak
Jerzy Okrajni
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Abstract

The flow of the investigated fluid in a measuring system of a rheometer – a capillary or a slit between rotating parts – may be disturbed by anisotropic behavior of the fluid near the wall. This phenomenon, so-called wall slip, often takes place in concentrated suspensions and solutions of linear polymers and introduces experimental errors to measurement results. There are methods of correction of these errors in the case of capillary and coaxial cylinders measuring systems. In the cone and plate system the correction seems to be more difficult because the width of the gap between cone and plate changes along the radius and thus the influence of the wall slip on the shear stress varies along the radius in an unpredictable and complicated manner. This dependency of the shear stress on the distance from the axis underlies the presented method of correction of experimental results obtained in the cone and plate system. The method requires several series of measurements of shear stress vs. shear rate performed using one measuring set, at various degrees of filling the gap.

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Authors and Affiliations

Tomasz Kiljański
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Abstract

The main aim of the study is an assessment of models suitability for steel beams made of thin-walled cold-formed sigma profiles with respect to different numerical descriptions used in buckling analysis. The analyses are carried out for the sigma profile beam with the height of 140 mm and the span of 2.20 m. The Finite Element (FE) numerical models are developed in the Abaqus program. The boundary conditions are introduced in the formof the so-called fork support with the use of displacement limitations. The beams are discretized using S4R shell finite elements with S4R linear and S8R quadratic shape functions. Local and global instability behaviour is investigated using linear buckling analysis and the models are verified by the comparison with theoretical critical bending moment obtained from the analytical formulae based on the Vlasow beam theory of the thin-walled elements. In addition, the engineering analysis of buckling is carried out for a simple shell (plate) model of the separated cross-section flange wall using the Boundary Element Method (BEM). Special attention was paid to critical bending moment calculated on the basis of the Vlasov beam theory, which does not take into account the loss of local stability or contour deformation. Numerical shell FE models are investigated, which enable a multimodal buckling analysis taking into account interactive buckling. The eigenvalues and shape of first three buckling modes for selected numerical models are calculated but the values of critical bending moments are identified basing on the eigenvalue obtained for the first buckling mode.
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Authors and Affiliations

Katarzyna Rzeszut
1
ORCID: ORCID
Ilona Szewczak
2
ORCID: ORCID
Patryk Różyło
3
ORCID: ORCID
Michał Guminiak
4
ORCID: ORCID

  1. Poznan University of Technology, Institute of Building Engineering, Marii Skłodowskiej-Curie 5, 60-965 Poznan
  2. Lublin University of Technology, Faculty of Civil Engineering and Architecture, ul. Nadbystrzycka 38D,20–618 Lublin, Poland
  3. Lublin University of Technology, Faculty of Mechanical Engineering, ul. Nadbystrzycka 38 D, 20–618 Lublin, Poland
  4. Poznan University of Technology, Institute of Structural Analysis, Marii Skłodowskiej-Curie 5, 60-965 Poznan, Poland
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Abstract

This paper is a form of a report on conservation repairs on the internal walls of the semibasement of the Castle in Kórnik. One key element of these works is the desalination of the cellar walls. The excessive amount of salt results from a number of measures undertaken towards the end of the 19th c. and in the early 20th c., in order to rescue the architectural gem against a disaster. Carried out in the early 1950s, the cebertization (petrification of soil) proved to be the most spectacular measure leading to the stabilization of the structure. Unfortunately, however, this operation generates a side effect in the form of a huge amount of harmful salts, which permeate from the soil into the castle walls, leading to their gradual destruction.
In view of the progressing degradation of the walls in the castle cellars, measures leading to the elimination of the increased level of dampness and the damaging salts in the walls were implemented as of 2012. After works stabilising the level of dampness were carried out, the process of desalination, i.e. removal of salt from the structure of the walls, was undertaken as the subsequent stage – and is currently in progress. Special compresses placed onto the surface of the salinated building are used for the purpose.
The scale of the facility and the complexity of desalination itself resulting from the size and heterogeneity of the semibasement walls enforced the necessity to determine the appropriate scope of the works and assign them individually to each wall in the particular parts of the cellars. In the course of a year, in three stages, the majority of the wall surface was successfully covered with the first compress. The desalination method adopted does not bring about instant results, and the possibility to assess its final effects requires time.
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Authors and Affiliations

Katarzyna Wypych
1
ORCID: ORCID

  1. Biblioteka Kórnicka
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Abstract

The aim of this study was to determine how the change of glass laminate fibres to flax fibres will affect the stability of thin-walled angle columns. Numerical analyses were conducted by the finite element method. Short L-shaped columns with different configurations of reinforcing fibres and geometric parameters were tested. The axially compressed structures were simply supported on both ends. The lowest two bifurcation loads and their corresponding eigenmodes were determined. Several configurations of unidirectional fibre arrangement were tested. Moreover, the influence of a flange width change by ±100% and a column length change by ±33% on the bifurcation load of the compressed structure was determined. It was found that glass laminate could be successfully replaced with a bio-laminate with flax fibres. Similar results were obtained for both materials. For the same configuration of fibre arrangement, the flax laminate showed a lower sensitivity to the change in flange width than the glass material. However, the flax laminate column showed a greater sensitivity to changes in length than the glass laminate one. In a follow-up study, selected configurations will be tested experimentally.
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Bibliography

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[20] J. Gawryluk and A. Teter. Experimental-numerical studies on the first-ply failure analysis of real, thin-walled laminated angle columns subjected to uniform shortening. Composite Structures, 269:114046, 2021. doi: 10.1016/j.compstruct.2021.114046.
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Authors and Affiliations

Jarosław Gawryluk
1
ORCID: ORCID

  1. Department of Applied Mechanics, Faculty of Mechanical Engineering, Lublin University of Technology, Lublin, Poland
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Abstract

The study is devoted to a parametric analysis of the stability and load carrying capacity of prismatic segment shells built of rectangular sections of cylindrical shells and subjected to compression. Segment shells (columns) with a constant crosssectional area (weight) have been analysed and all the results obtained have been compared with the results obtained for the cylindrical shell with a radius R and a thickness c; First, an influence of geometrical parameters of the cross-section of single-layer isotropic shells has been analysed and such profiles have been sought for which the load carrying capacity is significantly higher than in the case of the cylindrical shell. Then, for a selected shape of the shell (apart from higher load carrying capacity, this choice could be influenced by other factors such as, e.g. easiness of manufacturing), an effect of the arrangement and thickness of orthotropic layers of the shell (laminate) on the stability and load carrying capacity has been investigated. The analysis has shown that one can design a segment shell made of the same orthotropic material and characterised by higher resistance to buckling and load carrying capacity than a single-layer cylindrical orthotropic shell. The results are depicted in the form of plots.
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Authors and Affiliations

Marian Królak
Zbigniew Kolakowski
Tomasz Kubiak
ORCID: ORCID
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Abstract

The aim of this research was to model the performances of energy and exergy on a Trombe wall system to enable an adequate thermal comfort. The main equations for the heat transfer mechanisms were developed from energy balances on subcomponents of the Trombe wall with the specification of the applicable initial and boundary conditions. During the incorporation of the PCM on the Trombe wall, the micro-encapsulation approach was adopted for better energy conservation and elimination of leakage for several cycling of the PCM. The charging and discharging of the PCM were equally accommodated and incorporated in the simulation program. The results of the study show that an enhanced energy storage could be achieved from solar radiation using PCM-augmented system to achieve thermal comfort in building envelope. In addition, the results correspond with those obtained from comparative studies of concrete-based and fired-brick augmented PCM Trombe wall systems, even though a higher insolation was used in the previous study.
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Bibliography

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Authors and Affiliations

Benjamin O. Ezurike
1
ORCID: ORCID
Stephen A. Ajah
1
ORCID: ORCID
Uchenna Nwokenkwo
1
ORCID: ORCID
Chukwunenye A. Okoronkwo
1
ORCID: ORCID

  1. Department of Mechanical/Mechatronics Engineering, Alex Ekwueme Federal University Ndufu-Alike, Nigeria
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Abstract

In Poland, in recent years, there has been a rapid accumulation of sewage sludge – a by-product in the treatment of urban wastewater. This has come about as a result of infrastructure renewal, specifically, the construction of modern sewage treatment plants. The more stringent regulations and strategic goals adopted for modern sewage management have necessitated the application of modern engineering methodology for the disposal of sewage sludge. One approach is incineration. As a consequence, the amount of fly ash resulting from the thermal treatment of municipal sewage sludge has grown significantly. Hence, intensive work is in progress for environmentally safe management of this type of waste. The aim of the experiment was to evaluate the possibility of using the fly ash that results from municipal sewage sludge thermal treatment (SSTT) as an additive to hardening slurries. The article presents the technological and functional parameters of hardening slurries with an addition of fly ash obtained by SSTT. Moreover, the usefulness of these slurries is analyzed on the basis of their basic properties, i.e., density, contractual viscosity, water separation, structural strength, volumetric density, hydraulic conductivity, compressive and tensile strength. The research on technological and functional properties was carried out, the aim of which was to determine the practical usefulness of the hardening slurries used in the experiment. Subsequently, leaching tests were performed for heavy metals in the components, the structure of the hardening slurries. An experiment showed leaching of hazardous compounds at a level allowing their practical application. The article presents the potential uses of fly ash from SSTT in hardening slurry technology.
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Bibliography

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Authors and Affiliations

Paweł Falaciński
1
ORCID: ORCID
Małgorzata Wojtkowska
1

  1. Warsaw University of Technology, Faculty of Building Services, Hydro and Environmental Engineering, Warsaw
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Abstract

Green walls, along with green roofs, parks, and vertical gardens, belong to the green infrastructure of cities, which will encompass the majority of humanity in the coming decades. Green infrastructure benefits both urban residents and nature in the urban landscape, although there is no scientific consensus on the extent to which green walls, especially green facades, impact biodiversity in cities. This study examined the influence of green facades on the richness of mammals, birds, and invertebrates, considering the species and age of the plants comprising the green facade in a medium-sized city located in southwestern Poland. It was found that the implementation of green facades significantly enhances species’ biodiversity compared to non-vegetated walls. Four synanthropic bird species were nesting on green facades: Eurasian collared dove ( Streptopelia decaocto), blackbird ( Turdus merula), house sparrow ( Passer domesticus) and woodpigeon ( Columba palumbus). For the beech marten (Martes foina), the green facades are a hunting ground for birds and their eggs. This simple and effective method of creating green walls provides benefits to local wildlife by creating habitats, shelter, and foraging opportunities for selected species. However, it is difficult to determine whether green facades contribute to the formation of ecological corridors in urban environments. The study also examined the social aspect related to the establishment and maintenance of green facades on the surveyed buildings.
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Authors and Affiliations

Grzegorz Oloś
1
ORCID: ORCID

  1. University of Opole, Faculty of Natural Sciences and Technology, Institute of Environmental Engineering and Biotechnology, 6A Kominka St, 45-035, Opole, Poland
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Abstract

In many application fields, thin-walled ductile iron castings can compete with castings made from aluminium alloys thanks as their show superior mechanical properties higher stiffness, vibrations damping as well as properties at higher temperatures. As problematic criterion in thin-walled cast-iron castings can be seen the graphitization ability and high sensitivity of the structure and the mechanical properties to the solidification rate.
The tests were curried on plate castings with wall thicknesses of 3, 5, and 8 mm, using inoculants based on FeSi70 with different contents of nucleation-active elements as aluminium, calcium, zirconium and magnesium. The inoculation was made by the in-mould method. In the experiments structures were achieved, differing by the graphite dispersity, structure and mechanical properties. The experiments have proved particularly a high sensitivity of the structure and the mechanical properties to the cooling rate of the sample castings. The influence of the inoculant type is less important than the influence of solidification rate.
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Bibliography

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Authors and Affiliations

J. Roučka
1
ORCID: ORCID
V. Kaňa
1
ORCID: ORCID
T. Kryštůfek
1
A. Chýlková
1

  1. Brno University of Technology, Faculty of Mechanical Engineering, Czech Republic
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Abstract

Dokra casting is famous for its Artistic value to the world but it is also sophisticated engineering. The technique is almost 4500 years old. It is practiced by the tribal artisans of India. It is a clay moulded wax-based thin-walled investment casting technique where liquid metal was poured into the red hot mould. Dimensional accuracy is always preferable for consumers of any product. Distortion is one of the barriers to achieving the accurate dimension for this type of casting especially for the bending parts. The cause and nature of the distortion for this type of casting must be analyzed to design a product with nominal tolerance and dimensional accuracy.
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Authors and Affiliations

R. Mandal
1
S. Roy
2
ORCID: ORCID
S. Sarkar
1
T. Mandal
3
A.K. Pramanick
2
G. Majumdar
1

  1. Mechanical Engineering Department, Jadavpur University, India
  2. Metallurgical and Material Engineering Department, Jadavpur University, India
  3. Metallurgy and Materials Engineering, IIEST Shibpur, India
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Abstract

The aim of this study was to determine the hardness and reduced modulus of elasticity of juvenile wood of Scots pine (Pinus sylvestris L.) using the nanoindentation method, and then to compare the results obtained with those of mature wood. The hardness of juvenile pine wood determined by means of the nanoindentation method was 0.444 GPa while for mature wood it was 0.474 GPa. Statistically significant differences between the values were found. The reduced modulus of elasticity in juvenile wood was 14.0 GPa and 16.4 GPa in mature wood. Thus, the hardness values obtained were about 7% higher, while the modulus of elasticity was 17% higher in mature wood. All determinations were made in the S2-layer of the secondary cell wall.

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Authors and Affiliations

P. Mania
M. Nowicki
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Abstract

The paper, which is a summary and supplement of previous works and research, presents the results of numerical and physical modeling of the GX2CrNiMoCuN25-6-3 duplex cast steel thin-walled castings production. To obtain thin-walled castings with wall in the thinnest place even below 1 mm was used the centrifugal casting technology and gravity casting. The analyzed technology (centrifugal casting) enables making elements with high surface quality with reduced consumption of batch materials and, as a result, reducing the costs of making a unitary casting. The idea behind the production of cast steel with the use of centrifugal technology was to find a remedy for the problems associated with unsatisfactory castability of the tested alloy.

The technological evaluation of the cast construction was carried out using the Nova Flow & Solid CV 4.3r8 software. Numerical simulations of crystallization and cooling were carried out for a casting without a gating system and sinkhead located in a mold in accordance with the pouring position. It was assumed that the analyzed cast will be made in the sand form with dimensions 250×250×120 mm.

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Authors and Affiliations

G. Stradomski
M. Nadolski
ORCID: ORCID
A. Zyska
B. Kania
D. Rydz
ORCID: ORCID
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Abstract

This paper presents the results of experimental research on the fabrication of thin-walled panels with longitudinal stiffening ribs by the single point incremental sheet forming technique. The bead-stiffened panels were made of Alclad 2024-T3 aluminium alloy sheets commonly used in aircraft structures. The influence of forming parameters and tool strategy on surface quality and the possibility of obtaining stiffening ribs with the required profile and depth was tested through experimental research. Two tool path strategies, spiral with continuous sinking and multi-step z-level contouring, were considered. The results of the experiments were used to verify the finite element-based numerical simulations of the incremental forming process. It was found that the main parameter which influences the formability of test sheets is the tool path strategy; the tool path strategy with multi-step z-level contouring allowed the rib to be formed to a depth of 3.53 mm without risk of cracking. However a greater depth of rib equal of 5.56 mm was achieved with the continuous tool path. The tool path strategy was also the main parameter influencing the surface finish of the drawpiece during the single point incremental forming process.
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Authors and Affiliations

B. Krasowski
1
ORCID: ORCID
A. Kubit
2
ORCID: ORCID
T. Trzepieciński
2
ORCID: ORCID
J. Slota
3
ORCID: ORCID

  1. Carpatian State School in Krosno, Krosno, Poland
  2. Rzeszow University of Technology, Faculty of Mechanical Engineering and Aeronautics, 12 Powstańców Warszawy Av., 35-959, Rzeszów, Poland
  3. Technical University of Košice, Košice, Slovakia
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Abstract

Following paper is focused on experimental and numerical studies of the behavior and energy absorption for both: quasi-static and dynamic axial crushing of thin-walled cylindrical tubes filled with foam. The experiments were conducted on single walled and double walled tubes. Unfilled profiles were compared with tubes filled with various density polyurethane foam. All experiments were done in order to possibility of the safety of the elements absorbing collision energy which can applied in car body. The dynamic nonlinear simulations were carried out by means of PAM-CRASH™ explicit code, which is dedicated calculation package to modelling of crush. Computational crushing force, plastic hinges locations and specimens post-crushed geometry found to be convergent with the real experiments results. Conducted experiments allowed to draw conclusion, that crashworthiness ability is directly proportional to foam density. The investigation of the experimental data revealed, that double walled tubes have greater energy absorbing ability. A proposed investigation enable to analyze and chosen of optimal parameters of these elements, which can use in automotive industry as an absorption energy components.

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Authors and Affiliations

P. Kaczyński
J. Karliński
M. Hawryluk
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Abstract

The use of FRP materials as external reinforcement of masonry structures has been recognized as an effective and minimally invasive method ofwall strengthening. The available literature and research reports confirmthe positive effect of the strip-like arrangement of composites with a horizontal, diagonal and – as shown in the paper – vertical configuration. The problem here is the proper estimation of the benefits of such FRP reinforcement, namely determining the real increase in shear strength. The paper described selected calculation procedures that can be found in the available literature (proprietary solutions), as well as in the published guidelines for the design of masonry walls strengthening using FRP materials. The results of experimental tests of sheared masonry walls made of AAC blocks and strengthened using vertical strips of carbon and glass fibres are briefly presented. Finally, based on the presented formulae, the values of the theoretical shear force resulted from the FRP contribution were calculated and detailed discussed.
The comparison of the experimental and theoretical shear forces showed that only one of the presented calculation methods gave a high agreement of the results for both carbon and glass sheets. In addition, it was noticed that in two cases the effects of strengthening – depending on the material used – drastically differed, which was not observed in the research.
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Authors and Affiliations

Marta Kałuża
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Civil Engineering, Akademicka 5, 44-100 Gliwice, Poland
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Abstract

Steel slag stone can be used as a substitute for coarse aggregate in concrete. In this study, the performance of steel slag concrete (SSC) in the wall brick structure was analyzed. The specimens with a steel slag replacement rate of 0%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% were designed, and the slump, stability, and carbonation resistance were tested. The results showed that the slump decreased with the increase of the replacement rate of steel slag stone. At the 60th min, the slump of SSC50 was 74 mm, which was 25.25% smaller than SSC00. When the replacement rate was more than 30%, cracks or fractures appeared, and the stability was destroyed. Twenty-eight days after the carbonation experiment, with the increase of the replacement rate, the carbonation resistance of the specimen decreased, and the performance was best when the replacement rate was 25%. The experimental results show that the performance of SSC is the best when the replacement rate of steel slag stone is 25%, which can be further promoted and applied in practice.
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Authors and Affiliations

Qing Su
1
ORCID: ORCID

  1. Wuchang University of Technology, No. 16, Jiangxia Avenue, Jiangxia District, Wuhan, China
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Abstract

The paper presents the results of testing the bearing resistance of the bolted joints of thin-walled profiles used in modular construction. The two types of joints currently applied in the construction industry were subjected to tests. One of them served as the reference sample, and the other as the research sample, which was used to find a solution that is more favorable in terms of the complexity of its production process and its bearing resistance. In addition to the modified shape of the end-plates, the bearing resistance of the joint was also analyzed with regards to the different diameters of bolts (bolts M12 and M16 were used), their classes (the difference between bolts of class 8.8 and 10.9 was examined), and also the number of them in the joint (3 or 5 bolts). Moreover, two thicknesses of steel sheets (3 mm and 4 mm), from which thin-walled cold-bent profiles were made, were used in the research. The bearing resistance tests were carried out with the use of a testing press of the authors’ own design. On the basis of the measurements, plots of the dependence between the deflection of the samples and the force acting in the middle of their span were drawn. It was shown that the tested profile joint had an increased bearing resistance by up to 26% when compared to the reference sample. The maximum destructive bending moment M was equal to 10.7 kN·m for the reference sample, and to 13.5 kN·m for the analyzed design solution. In total, 6 types of modified joints were made for the tests, of which five showed a comparable or higher bearing resistance than the reference sample. Each type of joint was tested by bending it in two directions in relation to the central axis of its cross-section.
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Authors and Affiliations

Karol Prałat
1
ORCID: ORCID
Arkadiusz Plis
1
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Civil Engineering, Mechanics and Petrochemistry, Łukasiewicza 17, 09-400 Płock, Poland
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Abstract

Vertical transport of wall-panels is a part of the prefabrication process of wood-framed buildings. The total dead weight of a wall is suspended on several lifting slings, pointwise clasping the top plate of the wall. This indicates, that all the weight of a wall is cumulated in sheathing-to-framing fasteners, usually staples. This article presents experimental investigations and analytical models evaluated for the description of light wood-framed walls in the process of lifting. Three different models cover the analytical approach: a model of a simple beam on elastic supports (BSS), a model of assembled beams (ACBS), three-dimensional (3D) spatial FE model of the wall (WFEM). Board-to-beam joint material parameters are determined on the base of experimental results. These connections are converted into two variants in the form of spring elements for 2D analysis, and beam elements for 3D analysis.
The numerical results exhibit that the proposed models may correctly represent behavior of a real wall in lifting, applying elastic materials parameters.
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Authors and Affiliations

Jarosław Malesza
1
Czesław Miedziałowski
1
ORCID: ORCID

  1. Bialystok University of Technology, Faculty of Civil Engineering and Environmental Sciences, Wiejska 45A, 15-351 Bialystok, Poland
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Abstract

In the article, the authors presented the results of microbiological air quality studies in selected buildings with additional thermal insulation applied from the inside using a silicate and lime system, as well as the results of a survey study concerning the comfort of use of said buildings. The microbiological air quality studies, conducted in buildings immediately prior to and after the application of additional thermal insulation using silicate and lime sheets, demonstrated a significant decrease in the number of mould spores in interior spaces. This was also reflected in the results of a survey study. The survey study was conducted with users of public and commercial buildings and municipal housing buildings in Krakow. Thanks to the additional insulation applied from inside using the silicate and lime system, all of the utilitarian parameters of internal spaces had improved. The most significant changes concerned parameters like comfort of use, the aesthetic of the spaces and breathing comfort. According to experts, the silicate and lime system was also rated highly in terms of the analysed parameters.

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Authors and Affiliations

Elżbieta Radziszewska-Zielina
ORCID: ORCID
Piotr Czerski
Wojciech Grześkowiak
Patrycja Kwaśniewska-Sip

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