scholarly journals Improving the algorithm of choosing spacing and number of stiff supports against a concentrated force in steel-concrete beams

2021 ◽  
Vol 2 (7 (110)) ◽  
pp. 40-47
Author(s):  
Anatoliy Petrov ◽  
Andriy Paliy ◽  
Artem Naumenko ◽  
Serhii Sheptun ◽  
Maryna Ihnatenko ◽  
...  
Keyword(s):  
Concrete Beam ◽  
Building Materials ◽  
Concrete Beams ◽  
Steel Strip ◽  
Lateral Force ◽  
Longitudinal Force ◽  
Labor Costs ◽  
Concentrated Force ◽  
Calculated Load

A steel-concrete beam was taken as the study object. The algorithm of selecting the number of stiff supports for the steel-concrete beam loaded with a concentrated lateral force in the middle of the span has been refined. Stiff supports served to join the steel strip with concrete to ensure their joint performance. The algorithm was refined based on the condition of equality of the longitudinal force in the steel strip from the action of the calculated load and the maximum longitudinal force obtained after setting the supports. In this case, the longitudinal forces in all stiff supports, as well as the spacing of the stiff supports should be the same. A disadvantage of the known algorithm consists in the complexity of determining the coefficient φb2 taking into account the effect of long-term concrete creep on the element deformation without cracks. This coefficient fluctuates widely and depends on many factors. Besides, it is also insufficiently studied. Calculations for determining the number and spacing of stiff supports in a steel-concrete beam were conducted according to the proposed algorithm and in the Lira software package. The forces acting on the supports and spacing of the supports were the same. The force acting in the support was 8941.5 N. When selecting characteristics of the steel-concrete beam, maximum longitudinal force in the steel strip was obtained. The longitudinal force amounted to 35726 N. The same longitudinal force was obtained from the diagram of longitudinal forces obtained after setting the supports. This study was aimed at improving the design of steel-concrete beams. A rational number and placement of stiff supports ensure savings: the required amount of building materials is reduced and their cost is reduced due to cutting labor costs for their manufacture and operation

Application Research on Transformed Section Method in Stress Redistribution Deduced by Creep in Concrete Beam Reinforced with FRP

2011 ◽  
Vol 255-260 ◽  
pp. 35-39
Author(s):  
Guo Dong Zheng
Keyword(s):  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Internal Force ◽  
Stress Redistribution ◽  
Application Research ◽  
Section Method ◽  
Height Change ◽  
Stress And Deformation

For un-cracked reinforced concrete beam with FRP, the adjusted effective modulus theory (AEMM theory) is applied and the calculation method of internal force and stress redistribution of various materials under creep is given with the transformed section method. A comparative analysis is carried out from height change of the concrete beams, reinforcement ratio, FRP layers and the initial stress. The stress of the bars and FRP will increase over time and the degree of increase will be more obvious with the height of the beam and the reinforcement increased, but the concrete stress will be reduced accordingly. The conclusion plays an important role for the performance evaluation of the long-term stress and deformation of concrete beam reinforced with FRP.

METHOD OF MODELING A REINFORCED CONCRETE BEAM WITH DOUBLE REINFORCEMENT FOR STRENGTH, DEFORMATION AND FIRE RESISTANCE

2019 ◽  
Vol 9 (1) ◽  
pp. 4-9
Author(s):  
Sergey S. MORDOVSKY ◽  
Nikolay A. ILYIN ◽  
Denis A. PANFILOV ◽  
Valeriya N. TALANOVA ◽  
Yana A. BUZOVSKAYA
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Experimental Studies ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Scale Model ◽  
Technical Solution ◽  
Labor Costs

The article presents a new technical solution, which relates to the field of construction, in particular, to the testing of bending reinforced concrete elements - building beams for strength, deformation and fire resistance on a scale model. The new method of solution implies an increase in the information content, visual clarity and depth of experimental studies of reinforced concrete beams as a result of using the cost-effective way of designing geometric and forceful similarity to the scale model of reinforced concrete beams for strength, deformation and fire resistance. The proposed method allows us to estimate the limiting states of a reinforced concrete beam by strength, deformation and fire resistance; develop an analytical model for calculating the actual fire resistance; save on labor costs in the manufacture of large scale model of full scale design for its testing.

scholarly journals Application of Plastic Wastes in Construction Materials: A Review Using the Concept of Life-Cycle Assessment in the Context of Recent Research for Future Perspectives

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3549
Author(s):  
Tulane Rodrigues da Silva ◽  
Afonso Rangel Garcez de Azevedo ◽  
Daiane Cecchin ◽  
Markssuel Teixeira Marvila ◽  
Mugahed Amran ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Solid Waste ◽  
Building Materials ◽  
Construction Materials ◽  
Plastic Waste ◽  
Plastic Wastes ◽  
Solid Waste Generation ◽  
Alternative Processes

The urbanization process contributes to the growth of solid waste generation and causes an increase in environmental impacts and failures in the management of solid waste. The number of dumps is a concern due to the limited implementation and safe disposal of this waste. The interest in sustainable techniques has been growing in relation to waste management, which is largely absorbed by the civil construction sector. This work aimed to review plastic waste, especially polyethylene terephthalate (PET), that can be incorporated with construction materials, such as concrete, mortars, asphalt mixtures, and paving. The use of life-cycle assessment (LCA) is related, as a tool that allows the sustainability of products and processes to be enhanced in the long term. After analyzing the recent literature, it was identified that studies related to plastic wastes in construction materials concentrate sustainability around the alternative destination of waste. Since the plastic waste from different production chains are obtained, it was possible to affirm the need for a broader assessment, such as the LCA, providing greater quantification of data making the alternative processes and products more sustainable. The study contributes to enhance sustainability in alternative building materials through LCA.

scholarly journals Life Cycle Cost Analysis of a Single-Family House in Sweden

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 215
Author(s):  
Bojana Petrović ◽  
Xingxing Zhang ◽  
Ola Eriksson ◽  
Marita Wallhagen
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Single Family ◽  
Labor Costs ◽  
Construction Costs ◽  
Economic Parameters ◽  
A Minor ◽  
Family House ◽  
Replacement Operation

The objective of this paper was to explore long-term costs for a single-family house in Sweden during its entire lifetime. In order to estimate the total costs, considering construction, replacement, operation, and end-of-life costs over the long term, the life cycle cost (LCC) method was applied. Different cost solutions were analysed including various economic parameters in a sensitivity analysis. Economic parameters used in the analysis include various nominal discount rates (7%, 5%, and 3%), an inflation rate of 2%, and energy escalation rates (2–6%). The study includes two lifespans (100 and 50 years). The discounting scheme was used in the calculations. Additionally, carbon-dioxide equivalent (CO2e) emissions were considered and systematically analysed with costs. Findings show that when the discount rate is decreased from 7% to 3%, the total costs are increased significantly, by 44% for a 100-year lifespan, while for a 50 years lifespan the total costs show a minor increase by 18%. The construction costs represent a major part of total LCC, with labor costs making up half of them. Considering costs and emissions together, a full correlation was not found, while a partial relationship was investigated. Results can be useful for decision-makers in the building sector.

scholarly journals Influence of steel–concrete bond damage on the dynamic stiffness of cracked reinforced concrete beams

2018 ◽  
Vol 21 (13) ◽  
pp. 1977-1989 ◽  
Author(s):  
Tengfei Xu ◽  
Jiantao Huang ◽  
Arnaud Castel ◽  
Renda Zhao ◽  
Cheng Yang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Natural Frequencies ◽  
Concrete Beams ◽  
Dynamic Stiffness ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Reinforcing Bar ◽  
Sustained Loading ◽  
Inertia Model

In this article, experiments focusing at the influence of steel–concrete bond damage on the dynamic stiffness of cracked reinforced concrete beams are reported. In these experiments, the bond between concrete and reinforcing bar was damaged using appreciate flexural loads. The static stiffness of cracked reinforced concrete beam was assessed using the measured load–deflection response under cycles of loading and unloading, and the dynamic stiffness was analyzed using the measured natural frequencies with and without sustained loading. Average moment of inertia model (Castel et al. model) for cracked reinforced beams by taking into account the respective effect of bending cracks (primary cracks) and the steel–concrete bond damage (interfacial microcracks) was adopted to calculate the static load–deflection response and the natural frequencies of the tested beams. The experimental results and the comparison between measured and calculated natural frequencies show that localized steel–concrete bond damage does not influence remarkably the dynamic stiffness and the natural frequencies both with and without sustained loading applied. Castel et al. model can be used to calculate the dynamic stiffness of cracked reinforced concrete beam by neglecting the effect of interfacial microcracks.

Prediction Scheme of Torsional Strength of Reinforced Concrete Beam

2012 ◽  
Vol 214 ◽  
pp. 306-310
Author(s):  
Han Chen Huang
Keyword(s):  
Genetic Algorithm ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Ann Model ◽  
Torsional Strength ◽  
Prediction Scheme ◽  
Optimal Network

This study proposes a artificial neural network with genetic algorithm (GA-ANN) for predicting the torsional strength of reinforced concrete beam. Genetic algorithm is used to the optimal network structure and parameters. A database of the torsional failure of reinforced concrete beams with a rectangular section subjected to pure torsion was obtained from existing literature for analysis. This study compare the predictions of the GA-ANN model with the ACI 318 code used for analyzing the torsional strength of reinforced concrete beam. The results show that the proposed model provides reasonable predictions of the ultimate torsional strength of reinforced concrete beams and offers superior torsion accuracy compared to that of the ACI 318-89 equation.

Developing an economy based on knowledge and innovation in the context of the middle income trap

2015 ◽  
Vol 60 (10) ◽  
pp. 56-74
Author(s):  
Paweł Wieczorek
Keyword(s):  
Economic Growth ◽  
New Technologies ◽  
Current Model ◽  
Growth Theory ◽  
Labor Costs ◽  
Average Income ◽  
Middle Income ◽  
Endogenous Growth Theory ◽  
Middle Income Trap

The article is a contribution to the discussion on the necessity to change the current model of economic growth of Poland for model of economy based on knowledge and innovation. In this way, our country will be able to overcome the threats that might push the economy into the trap of the average income, expressed in long-term slowdown in GDP growth. The endogenous growth theory, formed after 1989 and characterized by duplication of Western technology, enabled relatively rapid growth by over 20 years. Currently, Poland to ensure an economic growth is facing the need for innovative technologies and innovation. Risks associated with middle income trap are very real because of the disappearance of comparative advantage, which results from relatively low labor costs. The creation in Poland conditions to accelerate economic growth requires action to increase the propensity of entrepreneurs to reach for new technologies and innovation and attractive market offer from the national centers for research and development.

scholarly journals Influence of stirrup spacing on shear resistance and deformation of reinforced concrete beams

2018 ◽  
Vol 7 (1) ◽  
pp. 126
Author(s):  
Latha M S ◽  
Revanasiddappa M ◽  
Naveen Kumar B M
Keyword(s):  
Concrete Beam ◽  
Concrete Beams ◽  
Bending Moment ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Cement Concrete ◽  
Simply Supported ◽  
Reinforced Cement ◽  
Flexural Reinforcement

An experimental investigation was carried out to study shear carrying capacity and ultimate flexural moment of reinforced cement concrete beam. Two series of simply supported beams were prepared by varying diameter and spacing of shear and flexural reinforcement. Beams of cross section 230 mm X 300 mm and length of 2000 mm. During testing, maximum load, first crack load, deflection of beams were recorded. Test results indicated that decreasing shear spacing and decreasing its diameter resulted in decrease in deflection of beam and increase in bending moment and shear force of beam.

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