scholarly journals Experimental and Numerical Investigations on Fire-Resistance Performance of Precast Concrete Hollow-Core Slabs

2021 ◽  
Vol 11 (23) ◽  
pp. 11500
Author(s):  
Inwook Heo ◽  
Khaliunaa Darkhanbat ◽  
Sun-Jin Han ◽  
Seung-Ho Choi ◽  
Hoseong Jeong ◽  
...  
Keyword(s):  
Fire Resistance ◽  
Precast Concrete ◽  
Load Ratio ◽  
Test Results ◽  
Hollow Core ◽  
Key Factor ◽  
Parametric Analyses ◽  
Cover Thickness ◽  
Resistance Performance ◽  
Extrusion Method

In this study, full-scale fire tests and finite element (FE) analyses are conducted to investigate the fire resistance performance of hollow-core slabs (HCSs) manufactured using the extrusion method. The deflection of the HCS specimens and the temperature distribution in the section according to the fire exposure time are measured and analyzed comprehensively, and the test results are compared with the FE analysis results. In addition, parametric analyses are conducted on 21 cases with the HCS depth, span length, hollow ratio in a section, cover thickness of concrete, and load ratio (i.e., the ratio of the external load to the ultimate load) as variables, based on which the fire resistance performance of the HCS according to each variable is investigated. The analysis results show that the load ratio is a key factor governing the fire resistance behavior of HCSs, whereas the effects of the cover thickness of concrete and the hollow ratio in a section are relatively slight within the range of variables examined in this study.

scholarly journals Postfire Safety Investigation on Prestressed RPC Beams after Exposure to Elevated Temperatures

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yan Kai ◽  
Zhang Yao ◽  
Cai Hao ◽  
Fan Lili ◽  
Xin Zhang
Keyword(s):  
Elevated Temperatures ◽  
Failure Process ◽  
Load Ratio ◽  
Damage Mechanism ◽  
Test Results ◽  
Intelligent Sensors ◽  
Reinforced Beams ◽  
Cover Thickness ◽  
And Control ◽  
Temperature Force

Since the postfire safety of prestressed RPC beams after exposure to elevated temperatures needs to be studied and proved, this paper prepares eight smart prestressed RPC beams with intelligent sensors built in to monitor the internal temperature, force, and strain. The residual bearing tests after fire are carried out. The failure process of the beams under static load with different fire durations cover thickness of tendons, load ratio, bonded and unbonded tendons, and partial prestressing ratio, which are investigated. The load-deflection curves, crack distributions and developments, and strain variations are obtained, in addition to the damage mechanism and failure mode of the beams. The results show that the load-deflection curve of the prestressed RPC beam after fire has obviously three polylines, and the deflection points are where the cracks expand and the tendons yield. The failure procedure is the same as that of under-reinforced beams, while the height of the crushing zone is much lower than that of the balanced-reinforced beam at room temperature. The whole span deformation demonstrates a strong catenary effect, and the midspan deflection is approximately 1/40 of the effective span. The postfire safety of the bonded prestressed RPC beams is superior to that of unbonded prestressed RPC beams. The test results of this paper provide a basis for the safety performance evaluation and control of prestressed RPC beams after fire.

Study on Estimate of Load Ratio of Doubly Reinforced Concrete Beam Exposed to the Standard Fire

2017 ◽  
Vol 737 ◽  
pp. 465-470
Author(s):  
Jae Hong An ◽  
In Hwan Yeo ◽  
Ki Soo Jeon ◽  
Ki Ho In
Keyword(s):  
South Korea ◽  
Fire Resistance ◽  
Concrete Beam ◽  
Load Ratio ◽  
Reinforced Concrete Beam ◽  
High Rise ◽  
Standard Fire ◽  
Loading Ratio ◽  
Resistance Performance ◽  
Reinforcement Beam

There are a lot of concerns on safety structure performance by being buildings to be large and high-rise. In particular, damage due to the fire recently leads to a large disaster and therefore a variety of countries operate the regulation on the fire resistance performance depending on the building structure. There are differences on the fire resistance design in each country but 50% of the design load is suggested to be reasonable for the normal temperature during the fire by applying the concept of the loading ratio to the fire resistance design of structures. Since the loading ratio is the factor having a major impact on the evaluation of the fire resistance performance, it should be preferentially considered. The study on setting up the loading ratio to evaluate the fire resistance performance and safety of structures has yet to be fully furnished in South Korea. Therefore, in this paper, the loading ratio proper for the construction status in South Korea is to be taken into account and then the ratio is to be proposed on the single reinforcement beam.

Analysis on Fire-Resistance Performance of Beams Strengthened by Carbon Fiber Sheet Bonded with Inorganic Adhesive

2014 ◽  
Vol 501-504 ◽  
pp. 466-469
Author(s):  
Fu Xiong Wan
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Fire Resistance ◽  
Carrying Capacity ◽  
Load Ratio ◽  
Reinforcement Ratio ◽  
Capacity Increase ◽  
Fiber Sheet ◽  
Resistance Performance ◽  
Carbon Fiber Sheet

Fire-resistance performance of beams can be improved if the beam strengthened by carbon fiber sheet bonded with inorganic adhesive instead of organic epoxy adhesive with low softening temperature. However, Fire-resistance performance of the strengthened beams is not understood fully. Considering this issue, finite element analysis is done. Stating from building valid model of finite element, computing results are compared with experimental results, and rationality of the model is verified. Then plenty of parameter analysis is done. Effect of some parameters, such as Range of carrying capacity increase by sheet, reinforcement ratio, load ratio to carrying capacity and width of section, on fire-resistance performance of the strengthened beams is analysis. The results demonstrates that reinforcement ratio and load ratio to carrying capacity is the main factors influencing fire-resistance performance of the beam strengthened by carbon fiber sheet bonded with inorganic adhesive, While, range of carrying capacity increase by sheet and width of section have little influence on it. Beams, strengthened by carbon fiber sheet bonded with inorganic adhesive, and protected by Thick-typed Fireproof Coating, perform good fire behavior.

Fire Resistance Evaluation of Reinforced Concrete Columns Using Axial Load Ratio and Slenderness Ratio

2014 ◽  
Vol 905 ◽  
pp. 268-272
Author(s):  
In Hwan Yeo ◽  
Bum Yean Cho ◽  
Jae Hong An ◽  
Byung Youl Min
Keyword(s):  
Fire Resistance ◽  
Axial Load ◽  
Slenderness Ratio ◽  
Load Ratio ◽  
Cost Effective ◽  
Concrete Columns ◽  
Accurate Estimation ◽  
Structural Members ◽  
Standard Fire ◽  
Resistance Performance

Since the column members in buildings deal with both vertical and horizontal loads, appropriated amount of load should be estimated in order to evaluate the fire resistance performance of the columns under loaded condition. However, according to the ISO 834, the international standard for the evaluation of structural members, the fire resistance performance evaluation of column members is only based on the displacement and displacement rate under loaded condition in a standard fire. The purpose of this study is to suggest appropriate axial load ratios for the evaluation of fire resistance performance. The test conducted in this study produced appropriate axial load ratios for different slenderness ratios. They are expected to contribute to more accurate estimation of fire resistance performance and more efficient and cost-effective structural design.

Experimental Investigation on Fire Resistance of CES Columns Subjected to 3-Side Heating

2011 ◽  
Vol 250-253 ◽  
pp. 1657-1666
Author(s):  
Xiao Yong Mao ◽  
Wei Hua Guo ◽  
Li Li Li
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Fire Resistance ◽  
Structural Response ◽  
Load Ratio ◽  
Test Results ◽  
Key Factors ◽  
Fire Condition ◽  
Load Intensity ◽  
Steel Section

Results of experimental study on fire resistance of four concrete encased steel (CES) columns are presented. The four columns have the same steel section and reinforcements but different load intensity and load eccentricity, which were the key factors for fire resistance of CES columns under fire condition. The tested results are utilized to study the effect of various parameters on thermal and structural response of CES columns. Spalling of CES columns under fire condition are also investigated. Test results show that CES columns under 3-side heating have higher fire resistance than that under 4-side heating. Also, load ratio and load eccentricity have noticeable influence on the fire resistance of CES columns. In addition, spalling of concrete decreases the fire resistance of CES columns.

Experimental Study on Fire Resistance Performance of Glulam Beams

2012 ◽  
Vol 193-194 ◽  
pp. 539-543
Author(s):  
Zhao Peng Ni ◽  
Pei Fang Qiu
Keyword(s):  
Fire Resistance ◽  
Failure Modes ◽  
Test Results ◽  
Fire Performance ◽  
Standard Fire ◽  
Resistance Performance ◽  
Fire Resistance Rating ◽  
Resistance Rating ◽  
Resistance Tests

Abstract : A series of standard fire-resistance tests were carried out to study the fire performance, failure modes and fire-resistance ratings of glulam beams. The test results showed that these glulam beams performed well during the tests, and the fire-resistance rating requirements can be achieved as expected. The study has provided necessary knowledge and experimental data for the determination of fire-resistance performance of glulam beams in the fire code of China.

An Experimental Study on the Fire Behavior of CFT Columns under the Constant Axial Loading Condition in Fire

2012 ◽  
Vol 446-449 ◽  
pp. 1298-1306
Author(s):  
Hyung Jun Kim ◽  
Heung Youl Kim ◽  
In Hwan Yeo
Keyword(s):  
Boundary Condition ◽  
Fire Resistance ◽  
Fire Behavior ◽  
Load Ratio ◽  
Steel Tube ◽  
Cross Sectional ◽  
Cross Sectional Size ◽  
Major Factors ◽  
In Fire ◽  
Resistance Performance

The temperature of the steel tube of a CFT column rises rapidly upon a fire causing the deterioration of its strength, while the concrete inside of the tube having large heat capacity provides fire-resistance performance. In order to employ CFT columns as fire-resistant structure, it is necessary to conduct studies on the factors exerting influence on structural capacities and the influence associated with each condition. Concrete’s compressive strength, cross-sectional size, axial load ratio and boundary condition are the major factors which are influential in fire-resistance performance. In particular, boundary condition between columns and beams is one of the major factors which decide fire-resistance performance because it exerts influence on load carrying capacity. The result of the test conducted in this study showed that fire-resistance time of 106 minutes was secured in the specimens with clamped ends and that of 89 minutes in those with pinned ends when cross-sectional size was 360 by 360. In the specimens with cross-sectional size of 280 x 280, fire-resistance time of 113 minutes was secured under the condition of clamped ends and that of 78 minutes was secured under the condition of pinned ends.

Analysis on Fire-Resistance Performance of Slabs Strengthened by Carbon Fiber Sheet Bonded with Inorganic Adhesive

2013 ◽  
Vol 477-478 ◽  
pp. 714-717
Author(s):  
Fu Xiong Wan
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Fire Resistance ◽  
Carrying Capacity ◽  
Load Ratio ◽  
Parameter Analysis ◽  
Capacity Increase ◽  
Fiber Sheet ◽  
Resistance Performance ◽  
Carbon Fiber Sheet

Fire-resistance performance of slabs can be improved if the slab strengthened by carbon fiber sheet bonded with inorganic adhesive instead of organic epoxy adhesive with low softening temperature. However, Fire-resistance performance of the strengthened slabs is not understood fully. Considering this issue, finite element analysis is done. Stating from building valid model of finite element, computing results are compared with experimental results, and rationality of the model is verified. Then plenty of parameter analysis is done. Effect of some parameters, such as range of carrying capacity increase by sheet, reinforcement ratio, load ratio to carrying capacity and thickness of slab, on fire-resistance performance of the strengthened slab is analysis. The results demonstrate that thickness of slab is the main factors influencing fire-resistance performance of the slab strengthened by carbon fiber sheet bonded with inorganic adhesive. While, range of carrying capacity increase by sheet, width of section and load ratio to carrying capacity have little influence on it. Slabs, strengthened by carbon fiber sheet bonded with inorganic adhesive, and protected by Thick-typed Fireproof Coating, perform good fire behavior.

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