The impact of time on the heat resistance of self-compacting high-performance concrete incorporated with recycled martials

Abed, Mohammed; Nemes, Rita; Lublóy, Éva

doi:10.1007/s10973-019-08263-z

Cited by 19 publications

(8 citation statements)

References 25 publications

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“…Figure 7 depicts the impact of various cooling procedures on the surface cracking behaviour of concrete specimens following increased temperature exposure for various fire exposure times. The concrete samples developed micro and macro fractures as the temperature and heating duration increased [74]. The fractures developed on the surface of the concrete specimens chilled by spraying water are noticeably broader than those generated on the surface of the concrete cooled by air.…”

Section: Surface Characteristicsmentioning

confidence: 89%

Microstructure investigation, strength assessment, and thermal modelling of concrete exposed to different heating cooling regimes

Anand

Thanaraj²,

Andrushia

et al. 2023

J Therm Anal Calorim

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Building fires are sometimes unavoidable due to unexpected accidents. During the fire, the structural elements are exposed to temperatures above 1000 °C. Structural concrete loses its strength and stiffness during the heating and cooling cycle. In most cases, during a real fire, the structural elements are cooled by water quenching. It is rare scenario that, buildings subjected to fire are cooled by natural air without forced water spraying. However, structural concrete’s residual strength (RS) in both cooling cases after the fire incident is entirely different. Therefore, an experimental study was conducted to understand concrete’s heating–cooling (H–C) behaviour subjected to standard fire temperature. Concrete with different grades, namely C20, C30, C40, and C50, is considered in the present investigation. Specimens were subjected to higher temperatures following ISO 834 guidelines, and then, temperature-exposed specimens were either cooled by natural air or spraying water. Investigations are carried out to evaluate fire-exposed concrete’s hardened, micro-structural, and thermal performance. The damage intensity of the concrete samples is investigated by observing the thermal crack pattern, crack width, and porosity. Relationships between the temperature exposure and RS of concrete were proposed to predict the RS of fire-affected air- and water-cooled specimens. Based on the results, it is found that water-sprayed specimens exhibit higher strength loss (SL) than natural air cool (AC). The difference in the RS of the two cooling regimes decreases with increase in heating durations. Damage level and intensity of thermal cracks are higher for water-cooled (WL) specimens having higher strength grades.

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Section: Surface Characteristicsmentioning

confidence: 89%

Microstructure investigation, strength assessment, and thermal modelling of concrete exposed to different heating cooling regimes

Anand

Thanaraj²,

Andrushia

et al. 2023

J Therm Anal Calorim

View full text Add to dashboard Cite

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“…By studying the effect of time on concrete performance after exposure to high temperatures, it has been found by the authors (Abed et al, 2019) that the heat resistance of compressive strength can be enhanced or slightly decrease with age, but the concrete (at the age of 270 days) behaved differently than at the age of 90 days. Heat resistance is a new parameter called heat resistance introduced by authors to express the total area under the curve of the relative residual strength (20-800 8C).…”

Section: Fire Resistance Of Recycled Aggregate Concretementioning

confidence: 99%

“…By studying the effect of time on concrete performance after exposure to high temperatures, it has been found by the authors (Abed et al. , 2019) that the heat resistance of compressive strength can be enhanced or slightly decrease with age, but the concrete (at the age of 270 days) behaved differently than at the age of 90 days.…”

Section: Fire Resistance Of Recycled Aggregate Concretementioning

confidence: 99%

Understanding the effect of recycled concrete aggregate and cementitious materials on concrete's fire resistance

Abed

Lublóy

2021

JSFE

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PurposeFire can severely affect concrete structures and with knowledge of the properties of materials, the damage can be assessed. Aggregate, cement matrix and their interaction are the most important components that affect concrete behaviour at high temperatures. The effect of incorporating recycled concrete aggregate or cementitious materials, namely, cement type and pulverized fly ash, are reviewed to provide a better understanding of their involvement in fire resistance.Design/methodology/approachMore investigation research is needed to understand the fire resistance of such sustainable concrete that was already constructed. The present study illustrates the effect of using recycled concrete aggregate and cementitious materials on the fire resistance of concrete. To do so, a literature review was conducted and relevant data were collected and presented in a simple form. The author's selected research findings, which are related to the presents study, are also presented and discussed.FindingsRecycled concrete aggregate enhances the concrete behaviour at high temperatures when it substitutes the natural aggregate by reasonable substitution (more than 25–30%). It also almost eliminates the possibility of spalling. Moreover, utilizing both supplementary cementitious materials with recycled concrete aggregate can improve the fire resistance of concrete. The incorporation of pulverized fly ash and slag in Portland cement or blended cement can generally keep the mechanical properties of concrete at a higher level after heating to a high temperature.Originality/valueRecycled concrete aggregate enhances the concrete behaviour at high temperatures when it substitutes the natural aggregate by reasonable substitution (more than 25–30%). It also almost eliminates the possibility of spalling. Moreover, utilizing both supplementary cementitious materials with recycled concrete aggregate can improve the fire resistance of concrete. The incorporation of pulverized fly ash and slag in Portland cement or blended cement can generally keep the mechanical properties of concrete at a higher level after heating to a high temperature.

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“…Moreover, it is beneficial in segmenting the crack elongation and filling the large pores which is valuable for bending resistance [36]. Farzadnia et al [37] found that titanium (TiO 2 ) improved the residual strength after high temperatures exposure [38]. A dosage of 2 g/kg of liquid superplasticizer (GLENIUM ® C 300 (AT)) was applied for each mix.…”

Section: Deterioration Of Microstructure and Crackingmentioning

confidence: 99%

Evaluation of the mechanical properties of high-strength cement paste at elevated temperatures using metakaolin

Abdelmelek

Lublóy

2020

J Therm Anal Calorim

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This paper presents a wide experimental study, in which it evaluates the performance of high-strength paste exposed to elevated temperatures up to 900 °C. Several factors have been investigated at the age of 90 days, i.e. metakaolin (MK) dosages, water to binder ratio (w/b) as well as elevated temperatures. Results proved that MK improves the relative residual compressive strength and relative residual bending strength showing a gain up to 52% and of 71% at 500 °C, respectively, compared to the pure cement paste in case of 0.3 w/b. The maximum use of MK is not more than 12%, and the optimum dosages were 9, 12, and 12% of MK replacements for 0.3, 0.35, and 0.4 w/b, respectively. The optimum dosage could change with changing w/b ratio and this up to the density of the microstructure which is controlled by the amount of w/b ratio and the packing effect of MK amount. In addition to the mechanical properties, the adoption of MK decreases the cracking of the specimens at elevated temperatures. SEM investigations show the positive physical morphology contribution of MK, specific surface area as well as its chemical composition for decreasing the Ca(OH) 2 effect. Different phases that formed during temperatures elevation are illustrated by TG analysis. Results showed the reason behind using MK on the cracking enhancement and mechanical properties improvement after high temperatures exposure. Meanwhile, the obtained optimum MK dosages at ambient temperature are not similar to that obtained at elevated temperatures.

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The impact of time on the heat resistance of self-compacting high-performance concrete incorporated with recycled martials

Cited by 19 publications

References 25 publications

Microstructure investigation, strength assessment, and thermal modelling of concrete exposed to different heating cooling regimes

Microstructure investigation, strength assessment, and thermal modelling of concrete exposed to different heating cooling regimes

Understanding the effect of recycled concrete aggregate and cementitious materials on concrete's fire resistance

Evaluation of the mechanical properties of high-strength cement paste at elevated temperatures using metakaolin

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