Coating protection of loaded RC columns to resist elevated temperature

Hodhod, Osama A.; Rashad, Alaa M.; Abdel-Razek, M. M.; Ragab, Ahmed

doi:10.1016/j.firesaf.2008.06.010

Cited by 27 publications

(16 citation statements)

References 1 publication

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“…This result is practical because the natural siliceous sand was used as a fine aggregate in this mix (L0). This type of fine aggregate (siliceous sand) has high thermal conductivity (0.361 W/mK) (Hodhod et al 2009;Rashad 2017). The obtained thermal conductivity of L0 is higher than some thermal conductivities found in the literature (Wang et al 2016;Longo et al 2020;Rashad et al 2021), lower than the others (Wongsa et al 2020;Seo et al 2020;Sivasakthi et al 2021), and within the range reported in De Rossi et al (2019).…”

Section: Thermal Conductivitysupporting

confidence: 67%

“…The incorporation of 25%, 50%, 75%, and 100% LECA instead of siliceous sand, by volume, can reduce the thermal conductivity of L0 from 0.899 W/mK to 0.797, 0.771, 0.695, and 0.621 W/ mK, respectively. This reduction is expected due to the lower density, higher porosity, and interconnected pores in the LECA resulting in lower thermal conductivity (0.27 W/mK) compared to that of siliceous sand (0.361 W/mK) (Hodhod et al 2009). The lowest thermal conductivity value (0.621 W/mK) obtained in the current investigation is lower than other insulating materials found in the literature such as 70% FA/30% slag geopolymer paste (0.935 W/mK) (Su et al 2019), 62% FA/38% slag geopolymer mortars containing either river sand fine aggregate (0.9 W/mK), or copper slag fine aggregate (1.5 W/mK) (Sivasakthi et al 2021).…”

Section: Thermal Conductivitymentioning

confidence: 99%

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An investigation on the performance of lightweight mortar-based geopolymer containing high-volume LECA aggregate against high temperatures

Ouda

Rashad

2021

Environ Sci Pollut Res

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The influence of lightweight expanded clay aggregate (LECA) on the physico-mechanical properties and microstructure of geopolymer mortar containing slag binder alkali-activated with sodium silicate solution before and after exposure to thermal loads was investigated. In the current procedure, siliceous sand was partially substituted with LECA fine aggregate at levels of 0%, 25%, 50%, 75%, and 100%, by volume. The effect of LECA on the performance before exposure was evaluated by measuring flowability, water absorption, bulk density, thermal conductivity, and compressive strength. To monitor the behavior after exposure, a batch of specimens having the same composition was subjected to high temperatures in the range of 400-1000 °C for 2 h with a heating rate of 5 °C/min. In a similar fashion, mass loss and residual compressive strength were determined. New phase-based geopolymers were examined using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The findings indicated that the incorporation of LECA up to 100% as an alternative to siliceous sand aggregate in geopolymer mortar has an adverse effect on compressive strength and water absorption, but has a positive effect on workability, thermal conductivity, and relative strength after exposure to elevated temperatures.

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Section: Thermal Conductivitysupporting

confidence: 67%

Section: Thermal Conductivitymentioning

confidence: 99%

An investigation on the performance of lightweight mortar-based geopolymer containing high-volume LECA aggregate against high temperatures

Ouda

Rashad

2021

Environ Sci Pollut Res

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“…When the water/cement ratio dropped to 0.30, the plastering layer reduced the cracking degree and inhibited the explosion of concrete. This is because the plastering layer can slow the rate of concrete heating, resulting in a decrease in temperature gradient and vapor pressure [17][18][19][20].…”

Section: Appearance Of Concrete After Heating Testmentioning

confidence: 99%

“…Up to now, there are many researchers who have analyzed the degradation mechanism properties of concrete components (beam, slab and column) with a plaster layer under high temperature by combining a scale structure test and finite element software. Hodhod indicated that traditional cement coating can delay the temperature rise of the RC column, and that traditional mortar coating can increase the residual load capacity of the RC column after 30 min at 650 • C [17]. Andrii reported that a fire-retardant coating can effectively improve the fire resistance of RC floor, and the fire resistance of RC floor increases with the thickness of fire-retardant coating [18].…”

Section: Introductionmentioning

confidence: 99%

High Temperature Degradation Mechanism of Concrete with Plastering Layer

Liu

Chen

2022

Materials

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At present, the research on the high temperature degradation of concrete usually focuses on only the degradation of concrete itself without considering the effect of the plastering layer. It is necessary to take into account the influence of the plastering layer on the high temperature degradation of concrete. With an increase in the water/cement ratio, the explosion of concrete disappeared. Although increasing the water/cement ratio can alleviate the cracking of concrete due to lower pressure, it leads to a decrease in the mechanical properties of concrete after heating. It is proved that besides the water/cement ratio, the apparent phenomena and mechanical properties of concrete at high temperature can be affected by the plastering layer. The plastering layer can relieve the high temperature cracking of concrete, and even inhibit the high temperature explosion of concrete with 0.30 water/cement ratio. By means of an XRD test, scanning electron microscope test and thermogravimetric analysis, it is found that the plastering layer can promote the rehydration of unhydrated cement particles of 0.30 water/cement ratio concrete at high temperature and then promote the mechanical properties of concrete at 400 °C. However, the plastering layer accelerated the thermal decomposition of C-S-H gel of concrete with a water/cement ratio of 0.40 at high temperature, and finally accelerate the decline of mechanical property of concrete. To conclude, the low water/cement ratio and plastering layer can delay the deterioration of concrete at high temperature.

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“…specific robot spray trajectories, Xia et al [34] detected and recorded temperature evolution continuously during preheating, spraying and cooling stages. Hodhod et al [35] determined the effect of different coating types with different thicknesses on the residual load capacities of reinforced concrete loaded column models. Using thermal spray coatings, Matthews et al [36,37] gave the roles of microstructure in the high temperature oxidation mechanism of Cr 3 C 2 ANiCr composite coatings.…”

Section: Introductionmentioning

confidence: 99%