Residual stress–strain relationship for concrete after exposure to high temperatures

Chang, Ying-Muh; Chen, Y.H.; Sheu, Maw Shyong; Yao, Gonghou

doi:10.1016/j.cemconres.2006.05.029

Cited by 364 publications

(202 citation statements)

References 6 publications

Supporting

Mentioning

154

Contrasting

Unclassified

Order By: Relevance

“…(2) was verified for two groups of concrete specimens with siliceous aggregate: the first group having with an original compressive strength of 40 MPa, similar to that of the columns investigated in this study, and the second group with an original compressive strength of 27 MPa, for a temperature up to 800 o C. Eurocode4 (2005) considers the same peak strain for concrete during heating and during the cooling down. However, a study on the residual mechanical properties of normal strength concrete with siliceous aggregate shows that Eurocode4 (2005) provides higher values for the residual peak strain than that of the test data by Chang et al (2006). This indicates that higher peak strains are estimated for concrete at the maximum temperature T than that after having cooled down to 20 o C. For stressed concrete, which is commonly the condition of concrete in columns, temperatures appear to have less effect on the peak compressive strain than it does for the unstressed concrete (Khennane and Baker, 1992).…”

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

“…Models are also available for post-fire residual peak strain of concrete. Chang et al (2006) proposed Eq. (2) for the residual peak compressive strain of unstressed concrete after fire.…”

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

“…(4). Several stress-strain models have been proposed for concrete in compression at elevated temperatures and at cooled temperatures such as Chang et al (2006), Nechnech et al (2002), Youssef and Moftah (2007), Eurocode2 (2004), Eurocode4 (2005, and Terro (1998), among others. The effects of concrete confinement on the peak and post-peak compressive response of concrete have been considered using available models which were modified for high temperature (Youssef and Moftah, 2007).…”

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

“…This may be due to increased temperature gradients resulting in increased cracking of the concrete and therefore losses in its mechanical properties. Chang et al (2006) proposed a temperature-dependant residual compressive strength model, Eq. (4), from compression tests of 108 specimens.…”

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

“…A study on post-fire response of reinforced concrete columns under axial load combined with uniaxial or biaxial bendings, concludes that this higher degradation in stiffness will result in large deformations and that should be considered for seismic response evaluation of a building subjected to earthquake after a fire (Chen et al, 2009). The tensile strength of concrete also reduces at elevated temperatures (EI-Hawary et al, 1997;Chang et al, 2006;Nechnech et al, 2002). Since the shear strength of concrete is dependent on its tensile strength, the loss of tensile strength capacity could increase the risk of shear failure for concrete elements in fire and therefore decrease their lateral/seismic load capacity.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Seismic Resistance of Fire-Damaged Reinforced Concrete Columns

Mostafaei

Vecchio

Bénichou

2009

Improving the Seismic Performance of Existing Buildings and Other Structures

View full text Add to dashboard Cite

The material in this document is covered by the provisions of the Copyright Act, by Canadian laws, policies, regulations and international agreements. Such provisions serve to identify the information source and, in specific instances, to prohibit reproduction of materials without written permission. For more information visit http://laws.justice.gc.ca/en/showtdm/cs/C-42Les renseignements dans ce document sont protégés par la Loi sur le droit d'auteur, par les lois, les politiques et les règlements du Canada et des accords internationaux. Ces dispositions permettent d'identifier la source de l'information et, dans certains cas, d'interdire la copie de documents sans permission écrite. Pour obtenir de plus amples renseignements : http://lois.justice.gc.ca/fr/showtdm/cs/C-42 ABSTRACTA study was carried out on the assessment of the residual strength and lateral/seismic load capacity of reinforced concrete columns after fire exposure. The mechanical properties of concrete after fire exposure, such as residual tension and compression strength, stiffness and constitutive responses, were reviewed. A nonlinear finite element analysis program, developed for three-dimensional reinforced concrete structures, was employed to estimate the post-fire axial and lateral performance of two full-scale reinforced concrete columns, tested previously at the National Research Council Canada. The results of the axial load-deformation response obtained from the analysis were compared and verified successfully with the test data. The lateral load and deformation responses of the specimens were then estimated using the numerical program. The results showed that both the lateral/seismic load capacity and ductility of the two reinforced concrete column specimens decreased noticeably due to the fire exposure. Studies are suggested on fire damage mitigation and post-fire shear strength recovery of reinforced concrete columns.

show abstract

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

“…Models are also available for post-fire residual peak strain of concrete. Chang et al (2006) proposed Eq. (2) for the residual peak compressive strain of unstressed concrete after fire.…”

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

Section: Mechanical Properties Of Fire-damaged Concretementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Seismic Resistance of Fire-Damaged Reinforced Concrete Columns

Mostafaei

Vecchio

Bénichou

2009

Improving the Seismic Performance of Existing Buildings and Other Structures

View full text Add to dashboard Cite

show abstract

Influence of mineral admixtures on mechanical properties of self‐compacting concrete under elevated temperature

Anand

Godwin

G³

2016

Fire and Materials

View full text Add to dashboard Cite

Self-compacting concrete (SCC) is a form of concrete that is capable of flowing into the congested interior of formwork and consolidating under the action of its own weight without segregation and bleeding. In the present investigation, an attempt has been made to study the effect of elevated temperature on mechanical properties of SCC specimens made with different mineral admixtures that were heated from 27 to 900°C and cooled by air or water. Silica fume, flyash, metakaolin were used as mineral admixtures. Master Glenium was used as superplasticizer, and Glenium Stream 2 was used as viscosity modifying agent. Mechanical properties of the cooled specimens such as compressive strength, tensile strength, flexural strength, and modulus of elasticity were found. Compressive, tensile, and flexural strengths of specimens were found to decrease by 73.18%, 65.05%, and 63.2%, and 85.2%, 83.52%, and 83.56% for the specimens with metakaolin that were heated and cooled by air and water, respectively. Similar reductions were found for the SCC specimens made with silica fume and flyash. Microstructure investigation has been carried out on SCC samples using scanning electron microscope and X-ray diffraction analytical techniques to understand the effect of temperature on decrease in strength.not exhibit the same level of performance as NSC under fire. Literature on this topic is scanty, and hence, an attempt has been made to understand the reduction in the strength of self-compacting concrete (SCC) made with different mineral admixtures that were exposed to higher temperature.Sivaraja [1] studied the effect of high temperature on mechanical strength properties of five different SCC mixes such as normal concrete, SCC with flyash (FA), SCC with silica fume (SF), SCC with rice husk ash, and SCC with 20% quarry sand. Mechanical properties such as compressive strength, split tensile strength, and modulus of rupture were obtained by conducting respective tests as per Indian standards. The strengths of the specimens subjected to high temperature were compared with those of unheated specimens.Neelam Pathak and Rafat Siddique [2] made an investigation on the properties of SCC such as compressive strength, splitting tensile strength, rapid chloride permeability, porosity, and mass loss when exposed to elevated temperatures. Mixes were prepared with three percentages of class F FA ranging from 30% to 50%. Test results clearly indicated that there was little improvement in compressive strength within temperature range of 200-300°C as compared with 20-200°C. A slight reduction in splitting tensile strength was found for the temperature ranging from 20 to 300°C with the increase in percentage of FA.Y. F. Chang et al.[3] carried out an investigation to obtain complete compressive stress-strain relationship for concrete after heating to temperatures of 100 to 800°C. From the results, a single equation for the complete stress-strain curves of heated concrete was developed. Through the regression analysis, the relationships of the mechanical pr...

show abstract

An empirical model for confined concrete after exposure to high temperature

et al. 2017

View full text Add to dashboard Cite

Summary In this study, constitutive relationships have been developed for confined concrete subjected to elevated temperature to specify the fire‐performance criteria for concrete structures after exposé to fire. This study extends over a total of 63 circular hoop confined concrete specimens that were casted and tested under concentric compression loading after exposure to high temperature. The test variables studied are the yield strength of transverse reinforcement, spacing of the hoop, and exposure to temperatures from ambient to 800°C. It is shown that all of these variables have significant influence on concrete behavior at different temperatures and further an improvement in the thermal resistance of concrete when confined using transverse steel reinforcement. On the basis of experimental results, a model for confined concrete after exposed to high temperature is proposed to predict the results of residual behavior after thermal cycles. The proposed empirical stress‐strain equations are suitable to predict the postfire behavior of confined normal strength concrete in compression. The predictions were found to be in good agreement and well fit with experimental results.

show abstract

Residual stress–strain relationship for concrete after exposure to high temperatures

Cited by 364 publications

References 6 publications

Seismic Resistance of Fire-Damaged Reinforced Concrete Columns

Seismic Resistance of Fire-Damaged Reinforced Concrete Columns

Influence of mineral admixtures on mechanical properties of self‐compacting concrete under elevated temperature

An empirical model for confined concrete after exposure to high temperature

Contact Info

Product

Resources

About