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Volume 16 (2021): Issue 2 (December 2021)

Volume 16 (2021): Issue 1 (June 2021)

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Volume 13 (2018): Issue 1 (December 2018)

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Volume 10 (2015): Issue 2 (November 2015)

Volume 10 (2015): Issue 1 (June 2015)

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Volume 9 (2014): Issue 1 (June 2014)

Volume 8 (2013): Issue 2 (November 2013)

Volume 8 (2013): Issue 1 (June 2013)

Volume 7 (2012): Issue 2 (November 2012)

Volume 7 (2012): Issue 1 (June 2012)

Journal Details
Format
Journal
eISSN
1338-7278
First Published
29 Mar 2013
Publication timeframe
2 times per year
Languages
English

Search

Volume 10 (2015): Issue 1 (June 2015)

Journal Details
Format
Journal
eISSN
1338-7278
First Published
29 Mar 2013
Publication timeframe
2 times per year
Languages
English

Search

12 Articles
access type Open Access

Flexural Fatigue performance of Alkali Activated Slag Concrete mixes incorporating Copper Slag as Fine Aggregate

Published Online: 01 Jul 2015
Page range: 7 - 18

Abstract

Abstract

The present investigation attempts a detailed study of mechanical properties and fatigue characteristics of a new class of Alkali Activated Slag Concrete (AASC) mixes incorporating Copper Slag (CS) as fine aggregates. The natural river sand is replaced with Copper Slag, upto 100% (by volume) as fine aggregate in these AASC mixes. The behavior of plain concrete prisms, cast with this range of AASC mixes under dynamic cyclic loads with sand/CS fine aggregates is studied and is compared with conventional OPC-based concrete specimens. The results indicate that incorporation of CS even upto 100% as fine aggregates, did not have any adverse effects on the mechanical properties of AASC mixes. The AASC mixes with CS displayed slightly better fatigue performance as compared to AASC mix with river sand. An attempt is also made herein to statistically describe the fatigue life data of AASC mixes using a 2-parameter Weibull distribution.

Keywords

  • alkali activated slag concrete
  • copper slag
  • flexural fatigue
  • sustainable concrete
access type Open Access

Criteria for defining the architectural form of wooden structures

Published Online: 01 Jul 2015
Page range: 19 - 26

Abstract

Abstract

Currently we can see many instances, both new and old, where the roof and roof structure dominates the design concept and becomes an important part of the internal space of a building. Wooden structures in these cases directly define the architectural form and shape of the building. It is therefore a major component of architecture, which includes newly created spaces and is an essential defining element of the interior. To a large extent this influences the parameters defining the volume of space i.e. its form. Wooden roof structures, however, find application in many different positions and relations to the total volume of the construction, exterior and interior,... I will attempt to define the criteria under which wooden beams form an integral part of the architectural concept. And we challenge the facts on specific examples.

Keywords

  • wood
  • architectural form
  • wooden roof structures
access type Open Access

Cycloids on the Spherical Surface

Published Online: 01 Jul 2015
Page range: 27 - 36

Abstract

Abstract

The article describes the creation of the normal cycloidal curve by rotation of the point about the normal of the circle on the spherical surface and binormal cycloidal curve created by rotation of the point about the binormal of the previous cycloidal curve. Cycloidal cyclical surfaces are created by moving circles along the curves lying in the normal plane of the curves. Described cycloidal cyclical surfaces are projected on the spherical surface. Varying parameters of the curves are generated different ornaments on the spherical surface.

Keywords

  • cycloidal curve
  • cycloidal cyclical surface
  • Frenet-Serret moving trihedron
  • spherical surface
access type Open Access

Assessing the effect of indoor environmental quality on productivity at office work

Published Online: 01 Jul 2015
Page range: 37 - 46

Abstract

Abstract

In a real environment makes it very difficult to evaluate the effect of a single parameter on human productivity, mostly because many of them are present at the same time and act together on each occupant. This study is aimed at investigation of selected office building to determine the presence of polluting agents such as volatile organic compounds, particulate matters and carbon dioxide and to assess the perceived productivity by office occupants. Occupants performed simulated office work consisting of three tasks in three office spaces. The mean values of total volatile organic compounds were in line with those found in other studies; taking into account the guideline value suggested by Molhave (200 μg.m-3). Mean values of PM10 mass concentrations exceeded the indoor limit value (50 μg.m-3) by 62.7% in office 1 and by 46.49% in reception. Concentrations of carbon dioxide in monitored office spaces were under the recommended concentration according to Pettenkofer (1800 mg.m-3).

Keywords

  • office
  • indoor environment
  • perceived productivity
  • occupants
access type Open Access

The Use of Artificial Neural Networks to Assess the Capacity of Transport Measures

Published Online: 01 Jul 2015
Page range: 47 - 56

Abstract

Abstract

In the area of logistics management both managers and engineers rely primarily on proven computational algorithms, for this reason, it is often difficult to convince them to the use of artificial neural networks in solving decision problems. The paper presents the possibilities of using the FANN library in building of a computer application applied in the area of logistics. The possibilities of the component are presented on the example of applications of artificial neural networks to estimate the capacity of transport vehicles based on their dimensions. The example presented in the work was solved with the use of a multi-network Layered Perceptron. The example depicted not only the possibility of using artificial neural networks for solving poorly structured tasks but also practical application of the TFannNetwork component

Keywords

  • logistics
  • transport
  • artificial neural networks
  • computer programming
access type Open Access

The Cost Monitoring of the Construction Machinery with Using the Stochastic Progress-Based S-curves

Published Online: 01 Jul 2015
Page range: 57 - 64

Abstract

Abstract

Contribution presents methodology for evaluating at-completion project performance status. Accurate cost and schedule project forecasts are difficult to generate when considering the impact of such events as unforeseen cost changes, material delays, scope deviation, changes to the project execution plan and poor subcontractor performance. In reality, the original estimate may be considered the first project forecast and at the point of project completion, the latest updated estimate (last forecast) and the actual amount of what is being expended should be the same. Final project performance is determined by comparing the planned budget and project duration, with the expected forecasted final budget and elapsed time. The stochastic S-curve methodology permits objective evaluation of project performance without the limitations inherent in a deterministic approach. This paper used the stochastic S curve to monitor the cost and time consumption in operation of the construction machines. The contribution presents a partial outcome from the dissertation thesis called the Interactive tools for resource optimization in construction.

Keywords

  • stochastic approach
  • construction machines performance
  • S-curves
  • forecast at-completion
  • evaluating at-completion
  • updated estimate
  • cost and time consumption
access type Open Access

Numerical and experimental determination of in-structure temperature profiles

Published Online: 01 Jul 2015
Page range: 65 - 72

Abstract

Abstract

When building physics simulations are done initial conditions express the actual hygrothermal state of building envelope. For the temperature field simulations initial condition is represented by the initial temperature in the body profile at the start of heat transfer. In-structure temperature varies quickly so temperature initial conditions are often neglected. Nevertheless in specific cases initial conditions have to be taken into an account even when simple temperature field simulations are done. The contribution shows various temperature initial conditions determination for insulated construction of outdoor test cell. Comparison of measured and calculated temperature profiles in structure shows correctness of start-up pre-calculation initial condition consideration

Keywords

  • start-up pre-calculation
  • initial temperature
  • temperature profile
  • measurement
  • simulation
access type Open Access

Changing Social Structure in Europe calls for Tailor-made, Barrier-free Living and new Interior Design

Published Online: 01 Jul 2015
Page range: 73 - 82

Abstract

Abstract

Europe is experiencing a demographic change, resulting in a change in social structure. People are living longer and birth rates are declining. This changing structure in Europe poses special challenges for housing designers and builders. A new approach in the design of real estate must be created and implemented that caters for the future needs of the occupants of the living space in all phases and allows residents to remain self-sufficient in their "home" for as long as possible. In the earliest stages of design, the typical requirements for each phase of life of future, potential residents must already be considered. This is especially true for people with special protection needs, such as those with visual or hearing impairments.

Keywords

  • Demographic Change
  • Barrier-free Design
  • Living Space in Europe
  • Life- Stage- Specific Needs
  • Modular Home Design
access type Open Access

Natural aggregate totally replacement by mechanically treated concrete waste

Published Online: 01 Jul 2015
Page range: 83 - 90

Abstract

Abstract

This paper presents the results obtained from the research focused on the utilization of crushed concrete waste aggregates as a partial or full replacement of 4/8 and 8/16 mm natural aggregates fraction in concrete strength class C 16/20. Main concrete characteristics such as workability, density and compressive strength were studied. Compressive strength testing intervals for samples with recycled concrete aggregates were 2, 7, 14 and 28 days. The amount of water in the mixtures was indicative. For mixture resulting consistency required slump grade S3 was followed. Average density of all samples is in the range of 2250 kg/m3 to 2350 kg/m3. The highest compressive strength after 28 days of curing, 34.68 MPa, reached sample, which contained 100% of recycled material in 4/8 mm fraction and 60% of recycled aggregates in 8/16 mm fraction. This achieved value was only slightly different from the compressive strength 34.41 MPa of the reference sample.

Keywords

  • recycled concrete aggregate
  • workability
  • compressive strength
access type Open Access

Physico-technical measurement of green roof in climate chamber module

Published Online: 01 Jul 2015
Page range: 91 - 98

Abstract

Abstract

Not for nothing it is said that "a good roof is priceless." Although it may lead to discussions, which roof is good, because there are a lot of requirements and criteria for the functional characterization. It must be understood that the roof structure defines the durability of the building as a unit, therefore it defines lifetime of other parts of the building and also the function of space that is covered by the roof. Therefore it is very important to pay particular attention to the design, as well as the realization of the roof structure. The aim of this publication is to judge the physical and technical parameters in the design of the roof coating module in a climatic chamber.

Keywords

  • glass systems
  • buildings materials
  • roof in situ measurements
  • laboratory measurements
  • building envelope.
access type Open Access

Selected findings from parametric studies determining the resistance of concrete panels in real terms

Published Online: 01 Jul 2015
Page range: 99 - 108

Abstract

Abstract

In the article selected results of parametric analysis of lightened reinforced concrete panels used in agricultural objects are presented. The aim of the analysis was to devise a parametric model that can be later on used for the simulation of behaviour of real ceiling panels when changing predefined parameters.

Keywords

  • concrete
  • steel reinforcement
  • ceiling panel
  • agricultural structure K-174
  • deflection
  • crack
  • parametric analysis
access type Open Access

Modern Methods for Cost Management in Construction Enterprises

Published Online: 01 Jul 2015
Page range: 109 - 118

Abstract

Abstract

Cost management should be seen as an essential function of enterprises which perform their activities in current market environment. One of the main factors affecting the level of achieved profit and favourable market position is cost structure. The company's ability to obtain necessary and reliable information on their own cost, subsequent processing and effective cost management is crucial for achieving success. This study focuses on cost management and the use of modern methods of cost management in construction enterprises. The aim of this paper is to identify approaches to cost management in Slovak construction enterprises, based on own empirical research.

Keywords

  • costs
  • cost management
  • information base
  • construction enterprises
12 Articles
access type Open Access

Flexural Fatigue performance of Alkali Activated Slag Concrete mixes incorporating Copper Slag as Fine Aggregate

Published Online: 01 Jul 2015
Page range: 7 - 18

Abstract

Abstract

The present investigation attempts a detailed study of mechanical properties and fatigue characteristics of a new class of Alkali Activated Slag Concrete (AASC) mixes incorporating Copper Slag (CS) as fine aggregates. The natural river sand is replaced with Copper Slag, upto 100% (by volume) as fine aggregate in these AASC mixes. The behavior of plain concrete prisms, cast with this range of AASC mixes under dynamic cyclic loads with sand/CS fine aggregates is studied and is compared with conventional OPC-based concrete specimens. The results indicate that incorporation of CS even upto 100% as fine aggregates, did not have any adverse effects on the mechanical properties of AASC mixes. The AASC mixes with CS displayed slightly better fatigue performance as compared to AASC mix with river sand. An attempt is also made herein to statistically describe the fatigue life data of AASC mixes using a 2-parameter Weibull distribution.

Keywords

  • alkali activated slag concrete
  • copper slag
  • flexural fatigue
  • sustainable concrete
access type Open Access

Criteria for defining the architectural form of wooden structures

Published Online: 01 Jul 2015
Page range: 19 - 26

Abstract

Abstract

Currently we can see many instances, both new and old, where the roof and roof structure dominates the design concept and becomes an important part of the internal space of a building. Wooden structures in these cases directly define the architectural form and shape of the building. It is therefore a major component of architecture, which includes newly created spaces and is an essential defining element of the interior. To a large extent this influences the parameters defining the volume of space i.e. its form. Wooden roof structures, however, find application in many different positions and relations to the total volume of the construction, exterior and interior,... I will attempt to define the criteria under which wooden beams form an integral part of the architectural concept. And we challenge the facts on specific examples.

Keywords

  • wood
  • architectural form
  • wooden roof structures
access type Open Access

Cycloids on the Spherical Surface

Published Online: 01 Jul 2015
Page range: 27 - 36

Abstract

Abstract

The article describes the creation of the normal cycloidal curve by rotation of the point about the normal of the circle on the spherical surface and binormal cycloidal curve created by rotation of the point about the binormal of the previous cycloidal curve. Cycloidal cyclical surfaces are created by moving circles along the curves lying in the normal plane of the curves. Described cycloidal cyclical surfaces are projected on the spherical surface. Varying parameters of the curves are generated different ornaments on the spherical surface.

Keywords

  • cycloidal curve
  • cycloidal cyclical surface
  • Frenet-Serret moving trihedron
  • spherical surface
access type Open Access

Assessing the effect of indoor environmental quality on productivity at office work

Published Online: 01 Jul 2015
Page range: 37 - 46

Abstract

Abstract

In a real environment makes it very difficult to evaluate the effect of a single parameter on human productivity, mostly because many of them are present at the same time and act together on each occupant. This study is aimed at investigation of selected office building to determine the presence of polluting agents such as volatile organic compounds, particulate matters and carbon dioxide and to assess the perceived productivity by office occupants. Occupants performed simulated office work consisting of three tasks in three office spaces. The mean values of total volatile organic compounds were in line with those found in other studies; taking into account the guideline value suggested by Molhave (200 μg.m-3). Mean values of PM10 mass concentrations exceeded the indoor limit value (50 μg.m-3) by 62.7% in office 1 and by 46.49% in reception. Concentrations of carbon dioxide in monitored office spaces were under the recommended concentration according to Pettenkofer (1800 mg.m-3).

Keywords

  • office
  • indoor environment
  • perceived productivity
  • occupants
access type Open Access

The Use of Artificial Neural Networks to Assess the Capacity of Transport Measures

Published Online: 01 Jul 2015
Page range: 47 - 56

Abstract

Abstract

In the area of logistics management both managers and engineers rely primarily on proven computational algorithms, for this reason, it is often difficult to convince them to the use of artificial neural networks in solving decision problems. The paper presents the possibilities of using the FANN library in building of a computer application applied in the area of logistics. The possibilities of the component are presented on the example of applications of artificial neural networks to estimate the capacity of transport vehicles based on their dimensions. The example presented in the work was solved with the use of a multi-network Layered Perceptron. The example depicted not only the possibility of using artificial neural networks for solving poorly structured tasks but also practical application of the TFannNetwork component

Keywords

  • logistics
  • transport
  • artificial neural networks
  • computer programming
access type Open Access

The Cost Monitoring of the Construction Machinery with Using the Stochastic Progress-Based S-curves

Published Online: 01 Jul 2015
Page range: 57 - 64

Abstract

Abstract

Contribution presents methodology for evaluating at-completion project performance status. Accurate cost and schedule project forecasts are difficult to generate when considering the impact of such events as unforeseen cost changes, material delays, scope deviation, changes to the project execution plan and poor subcontractor performance. In reality, the original estimate may be considered the first project forecast and at the point of project completion, the latest updated estimate (last forecast) and the actual amount of what is being expended should be the same. Final project performance is determined by comparing the planned budget and project duration, with the expected forecasted final budget and elapsed time. The stochastic S-curve methodology permits objective evaluation of project performance without the limitations inherent in a deterministic approach. This paper used the stochastic S curve to monitor the cost and time consumption in operation of the construction machines. The contribution presents a partial outcome from the dissertation thesis called the Interactive tools for resource optimization in construction.

Keywords

  • stochastic approach
  • construction machines performance
  • S-curves
  • forecast at-completion
  • evaluating at-completion
  • updated estimate
  • cost and time consumption
access type Open Access

Numerical and experimental determination of in-structure temperature profiles

Published Online: 01 Jul 2015
Page range: 65 - 72

Abstract

Abstract

When building physics simulations are done initial conditions express the actual hygrothermal state of building envelope. For the temperature field simulations initial condition is represented by the initial temperature in the body profile at the start of heat transfer. In-structure temperature varies quickly so temperature initial conditions are often neglected. Nevertheless in specific cases initial conditions have to be taken into an account even when simple temperature field simulations are done. The contribution shows various temperature initial conditions determination for insulated construction of outdoor test cell. Comparison of measured and calculated temperature profiles in structure shows correctness of start-up pre-calculation initial condition consideration

Keywords

  • start-up pre-calculation
  • initial temperature
  • temperature profile
  • measurement
  • simulation
access type Open Access

Changing Social Structure in Europe calls for Tailor-made, Barrier-free Living and new Interior Design

Published Online: 01 Jul 2015
Page range: 73 - 82

Abstract

Abstract

Europe is experiencing a demographic change, resulting in a change in social structure. People are living longer and birth rates are declining. This changing structure in Europe poses special challenges for housing designers and builders. A new approach in the design of real estate must be created and implemented that caters for the future needs of the occupants of the living space in all phases and allows residents to remain self-sufficient in their "home" for as long as possible. In the earliest stages of design, the typical requirements for each phase of life of future, potential residents must already be considered. This is especially true for people with special protection needs, such as those with visual or hearing impairments.

Keywords

  • Demographic Change
  • Barrier-free Design
  • Living Space in Europe
  • Life- Stage- Specific Needs
  • Modular Home Design
access type Open Access

Natural aggregate totally replacement by mechanically treated concrete waste

Published Online: 01 Jul 2015
Page range: 83 - 90

Abstract

Abstract

This paper presents the results obtained from the research focused on the utilization of crushed concrete waste aggregates as a partial or full replacement of 4/8 and 8/16 mm natural aggregates fraction in concrete strength class C 16/20. Main concrete characteristics such as workability, density and compressive strength were studied. Compressive strength testing intervals for samples with recycled concrete aggregates were 2, 7, 14 and 28 days. The amount of water in the mixtures was indicative. For mixture resulting consistency required slump grade S3 was followed. Average density of all samples is in the range of 2250 kg/m3 to 2350 kg/m3. The highest compressive strength after 28 days of curing, 34.68 MPa, reached sample, which contained 100% of recycled material in 4/8 mm fraction and 60% of recycled aggregates in 8/16 mm fraction. This achieved value was only slightly different from the compressive strength 34.41 MPa of the reference sample.

Keywords

  • recycled concrete aggregate
  • workability
  • compressive strength
access type Open Access

Physico-technical measurement of green roof in climate chamber module

Published Online: 01 Jul 2015
Page range: 91 - 98

Abstract

Abstract

Not for nothing it is said that "a good roof is priceless." Although it may lead to discussions, which roof is good, because there are a lot of requirements and criteria for the functional characterization. It must be understood that the roof structure defines the durability of the building as a unit, therefore it defines lifetime of other parts of the building and also the function of space that is covered by the roof. Therefore it is very important to pay particular attention to the design, as well as the realization of the roof structure. The aim of this publication is to judge the physical and technical parameters in the design of the roof coating module in a climatic chamber.

Keywords

  • glass systems
  • buildings materials
  • roof in situ measurements
  • laboratory measurements
  • building envelope.
access type Open Access

Selected findings from parametric studies determining the resistance of concrete panels in real terms

Published Online: 01 Jul 2015
Page range: 99 - 108

Abstract

Abstract

In the article selected results of parametric analysis of lightened reinforced concrete panels used in agricultural objects are presented. The aim of the analysis was to devise a parametric model that can be later on used for the simulation of behaviour of real ceiling panels when changing predefined parameters.

Keywords

  • concrete
  • steel reinforcement
  • ceiling panel
  • agricultural structure K-174
  • deflection
  • crack
  • parametric analysis
access type Open Access

Modern Methods for Cost Management in Construction Enterprises

Published Online: 01 Jul 2015
Page range: 109 - 118

Abstract

Abstract

Cost management should be seen as an essential function of enterprises which perform their activities in current market environment. One of the main factors affecting the level of achieved profit and favourable market position is cost structure. The company's ability to obtain necessary and reliable information on their own cost, subsequent processing and effective cost management is crucial for achieving success. This study focuses on cost management and the use of modern methods of cost management in construction enterprises. The aim of this paper is to identify approaches to cost management in Slovak construction enterprises, based on own empirical research.

Keywords

  • costs
  • cost management
  • information base
  • construction enterprises

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