Method for detecting property degradation of concrete after high temperature action

Abstract

The method of detecting performance degradation of concrete after high temperature action includes the following steps: 1. embedding temperature measuring element inside steel concrete before curing the concrete test piece, and pre-curing in constant temperature and constant humidity room one week ahead; and 2. testing the performance degradation through serial testing on internal temperature field change, physical and mechanical performance after high temperature action, ultrasonic detection and cracking status under the action of stable heat source at 795-805 deg.c and by adopting the time reaching steel concrete temperature of 250deg.c as the fire endurance. The present invention is simple and feasible, and has comprehensive testing and high accuracy.

Description

technical field [0001] The invention relates to a test method for performance degradation of concrete after high temperature action, and belongs to the field of building materials. Background technique [0002] Concrete material has been widely used in the field of construction engineering as the main building structure material in the history of more than 100 years due to the easy availability and cheapness of its raw materials, the convenience of construction, and its good physical and mechanical properties and durability. . [0003] However, in building fires and related concrete high-temperature tests, it was found that a series of physical and chemical changes have taken place in the structure of concrete itself after high temperature, which leads to the decline and deformation of concrete's load-bearing capacity. In addition, high-strength high-performance concrete, which has been booming in recent years and replaced traditional concrete in the field of construction e...

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Problems solved by technology

GB9978-1999 has high requirements on test devices and equipment, and general laboratory conditions cannot meet the requirements of fire resistance limit test, so it is not conducive to the promotion of this standard in scientific research and engineering applications

In addition, the GB / T 9978-1999 test is expensive, and the units that can be tested according to this standard are limited, which increases the difficulty of the test

[0009] Existing test methods have the defects of lack of reasonable basis for the high-temperature heating and heating system of concrete, single performance test indicators, not related to the actual application of concrete engineering, high requirements for test devices and equipment, and high test costs

Chinese patent literature related to the test method of performance degradation of concrete after high temperature exposure was not found after searching

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