Prestressed steel strand fire test device and method

Abstract

The present invention proposes a fire test device and method for prestressed steel strands, including: the scheme uses a built-in heating resistance wire in a box-type heating furnace to simulate a fire environment, and uses a wire displacement meter to measure the deformation and elongation of steel strands at high temperatures. Thus the prestress loss curve can be calculated. Due to the insulation thickness requirements of the box-type heating furnace, within the limited measurement gauge length of the prestressed steel strand, it is impossible to measure in the box-type heating furnace, so the measurement scheme provided by the present invention uses a horizontal bar and a column bar to increase the space And the measurement fixture assists the wire displacement meter to measure the elongation. The invention can accurately measure and calculate the stress-strain variation situation of the prestressed stress of the prestressed steel strand under the high temperature environment of fire, and can be applied to the performance research of the prestressed steel strand under high temperature.

Description

technical field [0001] The invention relates to the field of building material testing, in particular to a prestressed steel strand fire test device and method. Background technique [0002] Prestressed steel strand has the characteristics of light weight, superior physical properties, economical and practical, etc. It is a sustainable and reasonable structural form, and is widely used in long-span space structures such as cable-stayed bridges. Engineering practice shows that although the frequency of bridge fires is low, there are still fire risk sources that cannot be ignored, such as vehicle fires and ship fires. In 2007, the Mezcala cable-stayed bridge in Mexico caused a fire due to a traffic accident and caused one cable to break, and the adjacent cables were also damaged to varying degrees. [0003] The fire will cause a large prestress loss of the prestressed steel strands in the bridge and directly affect the bearing capacity of the prestressed bridge. Therefore, i...

AI Technical Summary

Problems solved by technology

The main factor of the prestress loss of the prestressed steel strand under the fire environment is the relaxation and creep of the prestressed steel strand under the action of high temperature, and due to the complexity of the prestressed structure and the test technology, the existing The fire temperature field simulation device and measurement method need to be verified and improved

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