Fire test device and method for pre-stressed steel strand

Abstract

The invention provides a fire test device and method for a pre-stressed steel strand. A fire environment is simulated through a built-in heating resistance wire of a box-type heating furnace and a deformation elongation value of the steel strand at a high temperature is measured by using a stay wire displacement meter, so that a pre-stress loss curve is obtained by calculation. Because of the requirement for the heat preservation thickness of the box-type heating furnace, measurement cannot be conducted in the box-type heating furnace within the limited measurement scale distance of the pre-stressed steel strand. However, on the basis of the provided measuring scheme, the elongation is measured by using a horizontal rod and a stand column rod which enlarge the space, a measurement clamp, and the stay wire displacement meter. The stress-strain change condition of the pre-stress of the pre-stress steel strand in a fire high-temperature environment can be measured and calculated accurately. The fire test device and method can be applied to the performance research of the pre-stress steel strand at a 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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