A high temperature resistant prestressed steel strand

Abstract

The invention relates to a high-temperature-resistant prestressed steel strand, which includes an inner core to wind the twisted wire outside the inner core, the inner core is made of a shape memory alloy material, and the twisted wire is provided with several strands in a spiral shape. Wrapped around the outside of the inner core. Compared with the prior art, the present invention uses an inner core made of SMA material. Under the induction of high temperature, SMA transforms from martensitic phase to austenite phase, returns to the original shape and generates prestress under the constraint, resulting in considerable The restoring force, so as to keep the prestress of the steel strand from being too low, and even increase it.

Description

technical field [0001] The invention relates to the field of building materials, in particular to a high temperature resistant prestressed steel strand. Background technique [0002] According to statistics, it generally takes 2 hours for a building fire to be extinguished from the onset of the fire. At this time, the temperature of the prestressed tendons inside the prestressed concrete structure usually reaches nearly 400°C. Under the action of high temperature, traditional steel strands will not only deteriorate in strength and stiffness, but also cause serious prestress loss due to the high temperature creep of itself and concrete, which not only reduces the bearing capacity of the structure, but also accelerates the cracking and deformation of the structure. Cracking and deformation accelerate the high temperature of the fire to spread to the inside of the components, further aggravating the loss of prestress and structural deformation, thus forming a vicious circle, wh...

AI Technical Summary

Problems solved by technology

The former method needs to change the existing steel casting process, which is difficult to promote in a large area, and the steel is prone to brittle fracture under low stress; the latter method will reduce the bonding stress between the steel strand and the concrete, and the fireproof coating is easy to Shedding under reciprocating loads such as earthquakes

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