<abstract><title style='display:none'>Abstract</title>The analysis of influence of factors that depend on construction characteristics of the vibrosieves with circular vibrations on screening efficiency is presented in this paper. The dependence of the screening efficiency on the aperture size, length and inclination of the screen, as well as on vibration amplitude, is considered. Based on obtained results, one can see that the screening efficiency increases with vibration amplitude and the screen length increase. Further, increases of the screen inclination and aperture size are causing an initial increase of the screening efficiency, which is later decreasing.</abstract>

Screening Efficiency Analysis of Vibrosieves with the Circular Vibrations

<abstract><title style='display:none'>Abstract</title>The bitumen binders in road pavements are exposed traffic loading effect at different climatic conditions. A resistance to these stresses depends on bitumen properties as well. The paper presents rheological properties (<italic>G*, δ, ν*</italic>) determined and compared for four bituminous binders (unmodified and polymer modified bitumen) at temperature 46 – 60 (80) °C and dynamic viscosity at temperature 130 – 190 °C (Brookfield viscometer). On the basis of viscosity results it is possible to set optimal production and compaction temperatures. Elastic and viscous behavior of binder in the middle temperature is determined in rheometers. The higher value of complex modulus, the stiffer bitumen binder is able to resist deformation. The greater content of elastic components (e.g. polymer in bitumen) varies mainly elastic-viscous properties of primary bitumen.</abstract>

Department of Highway Engineering, Faculty of Civil Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia.

Department of Materials Engineering, Faculty of Mechanical Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia.

Department of Construction Management, Faculty of Civil Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia.

Study of Rheological Properties of Bituminous Binders in Middle and High Temperatures

<abstract><title style='display:none'>Abstract</title> The quality of bituminous binders used in the construction and maintenance of road surfaces is currently assessed by empirical testing based on obtaining one value for specific boundary conditions, which were designed about 100 years ago. Basic empirical tests include the softening point and penetration, but the practice shows that these tests appear to be inadequate. The evaluation of changes of bitumen properties during the production and paving process of bituminous mixture is also important. The paper points out how the “traditional” tests as softening point and penetration and viscosity are sufficient to evaluate properties of bitumen binders.</abstract>

Routine Testing of Bitumen Binders

<abstract><title style='display:none'>Abstract</title> Analysis of wind flow acting upon high-rise buildings is a very common topic. This paper deals with experiment in the Boundary Layer Wind Tunnel (BWLT) in Bratislava and comparison with the computational fluid dynamics (CFD) simulation and values given in the Eurocode. The analyzed object was the model of building with circular cross section (cylinder). External wind pressure coefficients were compared in three height levels of model.</abstract>

Pressure Coefficients Acting Upon the Cylinder Obtained by Numerical and Experimental Analysis

<abstract><title style='display:none'>Abstract</title>The present study involved the utilization of crushed glass as an auxiliary additive in the manufacture of cement stabilized fly ash (CSF) bricks. The bricks were made with 1:1 proportion of fly ash and sand stabilized with 20 % cement. Crushed glass was used as replacement for the fine aggregate in increments of 10 % up to 40 % wherein the sand was completely replaced with crushed glass. The various mix proportions were then moulded into bricks with the addition of water by hand moulding method of forming the bricks and sun dried followed by sprinkle curing over a period of 21 days. The bricks were then subjected to compressive strength, water absorption and efflorescence tests to gauge its performance. The investigation revealed that the addition of crushed glass to the brick mix resulted in an increase in strength of the bricks, however, the maximum strength achieved could not achieve the strength of the control specimen. But the strength was higher than the minimum strength recommended by Bureau of Indian Standards (BIS) for stabilized blocks as well as burnt bricks. It also reduced the water absorption marginally while no efflorescence was seen in any of the combinations. A cost comparison revealed that the optimal combination with crushed glass was able reduce the cost of the brick by 20 %.</abstract>

Valorization of Crushed Glass as a Potential Replacement for Sand in Cement Stabilized Fly Ash Bricks

<abstract>
<title style='display:none'>Abstract</title>
Effective communication is necessary for the success of construction project performance. Due to its nature, effective communication is required to coordinate all parties involved in construction projects such as owners, project managers, engineers, subcontractors, etc. Few previous studies have addressed the issues of construction project communication, particularly in the communication planning stage. This paper aimed to investigate how far the communication planning has been effectively implemented in several construction projects in Jakarta and measure how big the influence to project performance. It adopts a quantitative method by distributing questionnaire surveys to contractors and consultants in Jakarta. Descriptive statistics were used to analyse the data which presents that communication planning has been implemented by 78.02 % of the responses and significantly impact the project performances. This paper offers useful implications for practitioners on how construction project teams (from contractors and consultants) should carefully manage the communication process particularly during its planning stage.
</abstract>

Measuring the Influence of Communication Planning Towards Construction Project Performance

<abstract>
<title style='display:none'>Abstract</title>
The article presents the possibilities of utilizing waste from the automotive industry, namely old tires, in constructing pavements. The application of shredded rubber creates conditions for devulcanization, which improves the rheological properties of the binder and ensures its better dissolution in asphalt. The focus is on assessing the condition of the pavement surface, measuring the noise level in the vicinity of the road, and quantifying and evaluating the cost of implementing an asphalt pavement design with a crumb rubber modifier (CRM). A visual inspection was performed after 6 years of pavement life. Based on the inspection outputs, the pavement surface structure was in a favourable condition with no permanent deformations. Verifying the acoustic properties showed a noise reduction compared to the road section with the modified asphalt pavement surface. Currently, the price of rubber-modified asphalt for pavement in Slovakia is on average 10 to 15 % higher than the price of other modified mixes. However, we can conclude that pavements with CRM are economically and especially ecologically more advantageous in the long run.
</abstract>

Research on the Long-Term Acoustic Efficiency of Asphalt Mixtures Using CRM in Test Sections of Slovak Roads

<abstract>
<title style='display:none'>Abstract</title>
All over the world, the need for energy is increasing, and the methods of obtaining it are harmful to the environment. Traditional energy resources are rapidly depleting. During the extraction and burning of fossil fuels, many different pollutants enter the environment. One of the renewable forms of energy is wind energy. Wind energy is mainly used to generate electricity in wind farms. Wind turbines are a unique source of noise because they are installed at a high height above the ground, and the noise emitted is fluctuating and manifests itself in a wide frequency range. Noise from wind turbines as low as 32 dB(A) is a strong nervous system irritant for some people, while noise of 40 dB(A) and above causes severe discomfort for many people [<xref ref-type="bibr" rid="j_cee-2023-0062_ref_001">1</xref>]. Detailed noise modeling was carried out in the considered area, assessing how noise affects individual dwellings, noise in the living environment of residential buildings were modeled. The noise level without background noise sources of the nearest residential environment was determined by modeling at 31.9 dB(A) during the night, while the limit value for the protection of human health according to HN 33:2011 is 45 dB(A).
</abstract>

Modelling and Evaluation of Noise Dispersion from Wind Turbine Operations

<abstract>
<title style='display:none'>Abstract</title>
Pavement distresses are among the major problems that affects to a decisive extent on the using (operational capacity) the roads and reducing their service life. Therefore, its require to limitation this distresses and knowing the reasons that lead to appearing this distresses and give the correction during the construction of roads. The major distresses is the rutting which increases at intersections and the check points when the vehicle is stopping. The reinforcement pavement layer became an important step of design and the reconstruction of pavement layers which is control of almost distress, reduce the maintenance cost, and provide long service life of roads. In this study will study using the mats of palm fronds in reinforcement pavement layers instead industrial materials due to existence the palms with large quantity in Iraq. The result display the using the mats of palms fronds reduce the rutting percent 96.7, 88.3, 83.3 at 40, 50, 60 ºC respectively at surface course according the test by wheel track machine.
</abstract>

Using the Mats of Palm Fronds in Reinforcement Pavement Layers

<abstract>
<title style='display:none'>Abstract</title>
The current work is directed to study the variation of suction with time and soil water characteristics curve (SWCC) for natural and treated gypseous soil treated with two types of additive (lime and silica fume) compacted at different initial degrees of saturation <italic>S</italic>0 = 20 and 50 %. Soil subjected to wetting in an upward direction. Three types of gypsum soils were experimented with different gypsum content 15, 35, and 60 % taken from various sites in Salah Al-dean government, Iraq. The main results show that the air-entry value, residual values, and the time required for the entire saturation stage increases with increasing gypsum content and treatment with lime and silica fume and they for soil treated with silica fume are greater than for soil treated with lime. The rate of flow for soil treated with silica fume is less than that of soil treated with lime. The treated soil is more effective in increasing the time required for the entire saturation stage and decreasing the rate of flow when compacted at an effective degree of saturation <italic>S</italic>0 = 50 %.
</abstract>

Suction Variation of Natural and Treated Unsaturated Gypseous Soils During Wetting

<abstract>
<title style='display:none'>Abstract</title>
Geopolymer concrete is a new concrete technology that emerged as an alternative to conventional concrete by replacing traditional Portland cement with geopolymer binders. Strengthening of concrete structures using CFRP composites has become an essential technique last decades. Most of the studies were conducted on conventional concrete of Portland cement. In this research, an experimental and finite element analysis has been conducted to assess the bonding properties between geopolymer concrete substrate and CFRP composites using near-surface mounted strengthening system. The program consisted of concrete prisms bonded with NSM CFRP laminate and tested using single-lap shear test set-up with different bond lengths. Bond-slip behaviour has also been evaluated. The experimental results exhibited significant bonding properties, achieving an average bonding stress between 8.97 and 15.58 relative to the bonding length. The numerical analysis showed comparable results and a good correlation with that of experimental work.
</abstract>

Experimental and Numerical Assessment of Bonding Between Geopolymer Concrete and CFRP Sheet Using NSM Techniques

<abstract>
<title style='display:none'>Abstract</title>
Numerous problems that can occur during regular building use may necessitate the need for reinforced concrete RC members to be strengthened. An increase in live loads or structural damage is two examples. Various techniques can be used to increase load-carrying capability. Concrete reinforcement with textile-carbon fiber (TCF) is a more recent option. For almost all active forces, this strengthening procedure is appropriate. For bending, shear, torsion, or axial forces, strengthening is an option. The experimental work for this study examined the impact of textile carbon mesh in reinforced concrete with various numbers of layers and sikadure-330 as the bonding material with different damage ratio (0%, 45%, 55% and 70%). As well as the flexural behavior of reinforced concrete beams strengthened with TCF, by casting and testing 13 beams under the monotonic load, one of them represented the control beam, they designed according to ACI 318-14 to ensure flexural failure. From the results obtained in this study it was shown that the flexural capacity of all strengthened beams increased as a consequence of TCF strengthening. Therefore, TCF jacketing is a very promising technique for increasing reinforced concrete flexural capability, which is necessary for retrofitting and strengthening.
</abstract>

Strengthening of Reinforced Concrete Beams with Textile-Reinforced Concrete

<abstract><title style='display:none'>Abstract</title>The article deals with the interaction of a reinforced concrete slab with subsoil. The paper contains a non-linear analysis based on an experiment of reinforced concrete slabs with dimensions 2000 x 2000 mm and thickness 150 mm. A steel mesh with a diameter of 8/100 mm was used as reinforcement. The calculations and analysis are complemented by a comparison with EC2 design approaches. The research area combines the design of concrete structure and geotechnical tasks. The real behavior of the concrete structure with subsoil is considered for the analysis for advanced design. The selected computational approach of nonlinear analysis allows to capture the change of stiffness after the creation of cracks and modelling the shear punch failure of the slab - the collapse of the structure. The paper focuses on comparing the experiment with the numerical model in select loaded states for various input parameters of subsoil. Based on the experiment and numerical analysis the failure mechanism was determined. It was the punching of the slab. The calculations and the experiment verified that the critically controlled perimeter is at a distance of 1<italic>d</italic>. The effect of the modulus of elasticity on the slab punch mechanism was verified. In case of low modulus of subsoil, the load-bearing capacity of the slab is significantly reduced. The punching mechanism is influenced not only by the mechanical properties of the concrete but also by the properties of the subsoil. The performed parametric study also verified the influence of the size the nominal cover reinforcement depending on the modulus of elasticity of the subsoil. The deformation variant finite element method and a 3D computational model were used for numerical modelling. Nonlinear analysis was based on the Newton-Rapson method.</abstract>

Numerical Analysis of Reinforced Concrete Slab with Subsoil

<abstract><title style='display:none'>Abstract</title>The study investigated the durability performance of lime and fly ash stabilized lateritic soil blocks subjected to conditions of alternate wetting and drying. A locally available lateritic soil was collected and characterized in the laboratory for its geotechnical properties. The soil was then stabilized using lime and fly ash of various combinations. The blocks were tested for their compressive strength, water absorption and efflorescence. Durability was evaluated by subjecting the blocks to three cycles of wetting and drying and testing its compressive strength. The investigation revealed that fly ash-lime stabilization was capable of producing stabilized blocks meeting the standard requirements of Indian codes in terms of compressive strength, water absorption and efflorescence. The results revealed that a combination of 10 % fly ash with 10 % lime was enough to stabilize the soil to achieve the strength of a class 20 block whereas a combination of 10 % fly ash and 14 % lime was required to achieve the strength of a class 30 block. Wetting and drying cycles resulted in a marginal increase in strength after the first cycle but reduction thereafter. The optimal combination of 10 % fly ash and 14 % lime resulted in less than 25 % loss in strength after three cycles of wetting and drying.</abstract>

Performance of Fly Ash - Lime Stabilized Lateritic Soil Blocks Subjected to Alternate Cycles of Wetting and Drying

<abstract><title style='display:none'>Abstract</title>The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.</abstract>

Existing Steel Railway Bridges Evaluation

<abstract><title style='display:none'>Abstract</title> In this paper, we address the historical comparison methods with current methods for the assessment of flammability characteristics for materials an especially for wood, wood components and wooden buildings. Nowadays in European Union brings harmonization in evaluated of standards into each European country and try to make one concept of evaluated the flammability properties. In each European country to the one standard level which will be used by evaluation of materials regarding flammability. In our article we focused mainly on improving the evaluation methods in terms of flammability characteristics of using materials at building industry. In the article we present examples of different assessment methods at their own test methods in terms of fire prevention. On the base of old compared of materials by STN, BS and DIN methods for testing materials on fire and new methods of evaluating the flammability properties regarding EU standards before and after starting the flash over.</abstract>

The Evaluation of Flammability Properties Regarding Testing Methods

<abstract><title style='display:none'>Abstract</title>The aim of the work is to improve the methodology for the dynamic computation of simple beam spans during the impact of high-speed trains.Mathematical simulation utilizing numerical and analytical methods of structural mechanics is used in the research.The article analyses parameters of the effect of high-speed trains on simple beam spanning bridge structures and suggests a technique of determining of the dynamic index to the live load. Reliability of the proposed methodology is confirmed by results of numerical simulation of high-speed train passage over spans with different speeds. The proposed algorithm of dynamic computation is based on a connection between maximum acceleration of the span in the resonance mode of vibrations and the main factors of stress-strain state. The methodology allows determining maximum and also minimum values of the main efforts in the construction that makes possible to perform endurance tests. It is noted that dynamic additions for the components of the stress-strain state (bending moments, transverse force and vertical deflections) are different. This condition determines the necessity for differentiated approach to evaluation of dynamic coefficients performing design verification of I and II groups of limiting state. The practical importance: the methodology of determining the dynamic coefficients allows making dynamic calculation and determining the main efforts in split beam spans without numerical simulation and direct dynamic analysis that significantly reduces the labour costs for design.</abstract>

Rating of Dynamic Coefficient for Simple Beam Bridge Design on High-Speed Railways

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 eISSN: 2199-6512  Civil and Environmental Engineering (CEE) is a scientific-technical journal, which...