A method for measuring the internal temperature field of fire-exposed concrete

Abstract

The invention relates to a method for measuring an internal temperature field of exposure-to-fire concrete. The method comprises (1), a detection position is determined, wherein the detection position can be selected to be at a direct exposure-to-fire surface of concrete; (2), sampling is carried out; to be specific, a core sample is drilled and taken at the surface of the exposure-to-fire part of the concrete; (3), thickness detection of a burning sparse layer is carried out; to be specific, the thickness of a burning sparse layer is tested and the thickeness x2 of the burning sparse layer at the position is obtained; (4), neutralized depth detection is carried out; to be specific, the concrete core sample is split off along a direction perpendicular to the external surface, a phenolphthalein alcoholic solution with the 1 to 2% of concentration is sprayed at the split-off surface, and a neutralized depth is tested when a neutralized and non-neutralized interface is clear, so that the neutralized depth x1 of the position is obtained; and (5), temperature field calculation is carried out. According to the invention, the internal temperature filed of the exposure-to-fire concrete can be obtained quantitatively and accurately by detecting the neutralization depth of the concrete, the thickness of the burning sparse layer, and the temperature of the environment of the concrete structure before a fire, so that the material property change of the exposure-to-fire component along the depth can be analyzed and thus a basis can be provided for follow-up processing decision making.

Description

technical field [0001] The invention belongs to the fire-burned concrete detection and evaluation method in the field of civil engineering, in particular to a method for measuring the internal temperature field of fire-fired concrete. Background technique [0002] At present, domestic and foreign methods for estimating the internal temperature field of concrete under fire (high temperature) can be classified into two categories: one is to estimate the internal temperature field of concrete by judging the over-fire temperature of the concrete surface, and the other is to estimate the internal temperature field of concrete through the heating curve. [0003] (1) The method of estimating the internal temperature field of concrete by judging the overheating temperature of the concrete surface: [0004] Such methods are often related to the highest overfire temperature and overfire time of the concrete surface. The maximum overfire temperature of the concrete surface can be empi...

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Problems solved by technology

Therefore, this method is not suitable for fire situations in open space structures such as bridges

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