Mechanical properties of light weight concrete at elevated temperature

Abstract

This study provides an experimental investigation on the mechanical properties of concrete with thermal expansion at elevated temperatures. To understand the mechanical properties at elevated temperature, normal and light weight concrete of 60 MPa grade was exposed to temperature range 20 (room temperature) to 700ºC under 0.0 f cu (compressive strength of concrete at room temperature, f cu ), 0.2 f cu , 0.4 f cu load conditions and compressive strength, elastic modulus, thermal strain and creep at target temperature were inspected. Experimental results show that light weight concrete has higher compressive strength, although the strength of normal weight concrete degenerated more sharply than the light weight concrete at elevated temperature. Moreover, the thermal strain (0.0 f cu , unstressed) and total strain (0.2 and 0.4 f cu , stressed) of normal weight concrete was higher than that of light weight concrete. The result of creep test was shown similar tendency between normal weight concrete and light weight concrete less than 300ºC. Matrix damage induced by the thermal expansion of the aggregate significantly influenced on the mechanical properties degradation of concrete at high temperature.

Strength and microstructure characteristics of concrete with different grade exposed to standard fire

“…This higher reduction is because of the inbuilt vapor pressure after subjected to high temperature. These results are in accordance with Kim et al (2015). It was reported that the strength of normal weight concrete decreased more sharply than the light weight concrete.…”

Diatomaceous earth aggregates based composite masonry blocks for bushfire resistance

“…Thus, their application in external walls for multiple fire/bushfire exposures is limited. Many research studies have also reported similar strength reduction in other lightweight masonry and concrete at elevated temperatures in comparison with conventional cement-sand mixes (Kim et al, 2015;Hernandez-Olivares and Barluenga, 2004;Aydın, 2008;Demirel and Keles ¸temur, 2010;Mydin and Wang, 2012). Cree et al (2013) stated that conventional concrete loses considerable unrecoverable strength when exposed to temperatures greater than 300 8C because of the variation of its chemical composition and physical structure (Arioz, 2007).…”

Investigation of the Residual Mechanical and Porosity Properties of Cement Mortar under Axial Stress during Heating

“…However, in actual concrete structures, the concrete members are stressed by the designed load and constrained by other members. Therefore, concrete in structures exposed to high temperatures is practically always heated under stress [ 15 , 16 ], and the thermal behaviors of stressed concrete are different from those of unstressed concrete [ 16 , 17 ]. The test on stressed concrete during heating has been employed by many researchers.…”

“…The same conclusion was reached by Tao et al [ 25 ], when a preload at a pre-stress ratio of 0.2 was applied on self-compacting concrete cylinder specimens. Kim et al did a series of experiments on the stressed concrete [ 7 , 16 , 26 ], and carried out experiments on the compressive strengths of light-weight and normal concrete at high temperature at different pre-stress ratios [ 16 ]. The results showed that the light weight concrete had a higher compressive strength, and Kim suggested that the stress applied to the concrete during heating should be controlled at less than 40% of the concrete strength at room temperature.…”