Analysis on Fire Resistance of Reinforced Concrete Beams Base on the Failure Probability

2010 ◽  
Vol 452-453 ◽  
pp. 197-200 ◽  
Author(s):  
Zhen Qing Wang ◽  
Zhi Cheng Xue ◽  
Mu Qiao
Keyword(s):  
Reinforced Concrete ◽  
High Temperature ◽  
Fire Resistance ◽  
Failure Probability ◽  
Reliability Index ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Cover Thickness

For the mechanical properties of reinforced concrete under high temperature with large deterioration, the reliability of reinforced concrete beams have been largely discounted. A calculation of fire resistance based on failure probability is given by this paper. Reinforced concrete beam is usually working with cracks. Since each section with cracks has possibility of destruction, the reliability of the beam is calculated by the minimum value of n crack-sections’ resistance. The plastic zone resistance of concrete under high temperature is considered in this paper. A simple and feasible time-variant model of the resistance of reinforced concrete beams under fire and a reliability index analysis method of reinforced concrete beams under fire has been given. The action of ISO834 temperature rising curve on the reliability index of different specifications of concrete beams at different time is analyzed. The action of main parameters on the reliability index changes with time is shown. The fire resistance considers the failure probability is given. The results show that increase the reinforcement ratio and concrete cover thickness appropriately are effective measures to improve the fire resistance limit of reinforced concrete beams.

Experimental Investigation on Temperature Distribution of Reinforced Concrete Beam

2012 ◽  
Vol 166-169 ◽  
pp. 1379-1382 ◽  
Author(s):  
Dong Fu Zhao ◽  
Zuo Kai You ◽  
Dong Dong Liu
Keyword(s):  
Temperature Field ◽  
Reinforced Concrete ◽  
Field Distribution ◽  
Fire Resistance ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Temperature Field Distribution ◽  
The Difference

To research the temperature field distribution of concrete beams, experiments on fire resistance of 6 reinforced concrete simple-supported beams were completed. Test results indicate that: the trends of the temperature field distribution in each section of beam are the same, but the difference of the values in each section is large; the larger section of beam is, the higher temperature of beam surface and the more slowly the heat transfer to the internal of beam, which shows the increase of concrete cover thickness can improve fire resistance of beams; After the fire, the gradient of temperature field distribution is very serious in the internal of beam; the higher the temperature of the fire, the bigger damage of reinforced concrete beams is.

scholarly journals Research on the Efficiency of Composite Beam Application in Multi-Storey Buildings

2020 ◽  
Vol 12 (20) ◽  
pp. 8328 ◽  
Author(s):  
Tomas Kinderis ◽  
Mindaugas Daukšys ◽  
Jūratė Mockienė
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Composite Beam ◽  
Concrete Beams ◽  
Residential Building ◽  
Reinforced Concrete Beam ◽  
Composite Beams ◽  
Reinforced Concrete Beams ◽  
Assessment Criteria ◽  
Floor Structure

Over the past decade, several types of composite slim floor constructions have been used in multi-storey buildings in Lithuania. In order to study the efficiency of composite beam application in steel-framed multi-storey buildings, Thorbeam (A1), Deltabeam (A2), slim floor beam (A3) and asymmetric slim floor beam (A4) were chosen and evaluated according to nine assessment criteria (beam cost (K1), initial preparation on site (K2), installation time (K3), complexity of installation technology (K4), labour costs (K5), fire resistance (K6), load bearing capacity (K7), beam versatility (K8), and availability of beams (K9)). First, the significance of the rating criteria was selected and the order of the ranking criteria was obtained (K1˃K7˃K3˃K6˃K4˃K5˃K2˃K8˃K9) by means of a survey questionnaire. Second, the beams were ranked according to the points given by the questionnaire respondents as follows: 160 points were given to A2, 144 points to A1, 129 points to A4, and 111 points to A3. Deltabeam is considered to be the most rational alternative of the four beams compared. Calculations done using the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) analysis method revealed that composite beam A2 was the best slim floor structure alternative for an eight-storey high-rise commercial residential building frame, A1 ranked second, A4 ranked third, and A3 ranked fourth. In addition, the four composite beams were compared to a reinforced concrete beam (A5) according to three assessment criteria (beam cost including installation (C1), beam self-weight (C2) and fire resistance (C3)). Deltabeam was found to be efficient for use as a slim floor structure in a multi-story building due to having the lowest cost, including installation, and self-weight, and the highest fire resistance compared to other composite beams studied. Although Deltabeams are 1.4 times more expensive than reinforced concrete beams, including installation costs, they save about 2.5% of the building’s height compared to reinforced concrete beams.

Experimental Research on the Cracking Behavior of GFRP/Steel Wire Composite Rebar Reinforced Concrete Beam Based on Cracking Mechanics

2012 ◽  
Vol 252 ◽  
pp. 17-22
Author(s):  
Chuan Wang ◽  
Li Li Sui ◽  
Qing Duo Hao ◽  
Qi Yu Lu
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Concrete Beams ◽  
Steel Wire ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Cracking Behavior ◽  
Limit Value ◽  
The Difference

The different mechanical property determines the difference on cracking behavior between GFRP/steel wire composite rebar reinforced concrete beams and steel rebar reinforced concrete beams according to cracking mechanics. In order to study the cracking behavior of concrete beams reinforced with GFRP/ steel wire composite rebar, five simply-supported beams were tested under three-point static load. The test variables were beam section size and concrete cover depth. Based on analysis on the test results, the calculation methods of cracking capacity and maximum crack width were proposed, and the limit value of crack width was suggested.

Experiment on the Deformation of the Reinforced Concrete Beam NSM Prestressed Steel Spiral Ribs

2011 ◽  
Vol 94-96 ◽  
pp. 1278-1285
Author(s):  
Chun Sheng Zhang ◽  
Mei Xiang Zhang ◽  
Ya Hong Ding
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Steel Wire ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Practical Engineering ◽  
General Deformation ◽  
Good Agreement

A new reinforcement technology with prestressed helical rib steel wire bonded in sawed grooves in the concrete cover is presented, based on the deficiency of the presented reinforcement methods. Four test beams NSM prestressed steel spiral ribs are tested in this paper. The stiffness expression of the reinforced concrete beams in different stages is derived and the stiffness formulas of the reinforced concrete beams are gained, based on the general deformation principles of reinforced concrete beams and the characteristics of the reinforced concrete beam NSM prestressed steel spiral ribs. The results of the calculation and the experimental results show good agreement. It shows that the reinforced concrete beam NSM prestressed steel spiral ribs can effectively delay the development of cracks, reduce the component deformation and increase its stiffness. The results provide an experimental basis for the reinforcement method in practical engineering applications.

A Time-Variant Reliability Analysis of Reinforced Concrete Beams Working with Cracks under High Temperature

2012 ◽  
Vol 197 ◽  
pp. 259-265
Author(s):  
Zhen Qing Wang ◽  
Mu Qiao ◽  
Yu Lai Han ◽  
Zhu Ju
Keyword(s):  
Reinforced Concrete ◽  
Reliability Index ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
First Order ◽  
First Order Second Moment ◽  
The Impact ◽  
Second Moment Method

The reliability of a reinforced concrete beam has been largely discounted when it under the action of fire. For a more accurate description of concrete beams’ reliability, the impact of cracks in reinforced concrete beams has been taking into account. Concrete is divided into elastic zone and plastic zone to calculate its strength. A simple and feasible time-variant model of reliability index of reinforced concrete beams under fire has been given. The effect of ISO834 temperature rising curve on the reliability index of concrete beam at different time has been analyzed. The reliability of a reinforced concrete beam under the ISO834 standard heating curve was assessed by first order second moment method.

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.

The Application Research of Reinforced Concrete Multi-Ribbed Hollow Composite Slab in the Road Slab Culvert

2011 ◽  
Vol 368-373 ◽  
pp. 307-311
Author(s):  
Dong Qi Zhao ◽  
Yi Jun Tang ◽  
Hui Li ◽  
Gui Feng Song ◽  
Feng Ling Guan
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Application Research ◽  
Composite Slab ◽  
The Road ◽  
High Integrity ◽  
Cover Design ◽  
Bottom Slab

Reinforced concrete cover in the road culvert cover design, in order to facilitate the construction, usually using precast reinforced concrete solid slab, but the overall cost is not low. This article researched a reinforced concrete multi-ribbed hollow composite slab, it based on the theory of reinforced concrete multi-ribbed slab structures, using a precast reinforced concrete ribbed slab as the bottom die, then poured reinforced concrete beams and panels rib ,and them constituted a whole stack of reinforced concrete ribbed hollow slab. This kind of cover, compared with the precast reinforced concrete solid cover, is not only good mechanical properties, high integrity, but also saving concrete, steel, and bottom slab appeared smooth and fine, lower construction cost.

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.

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