Steel used for non-cold-working connection

Abstract

The invention discloses steel used for a non-cold-working connection, and the steel has the characteristics of small screw pitch, small lead angle and high thread height; and the steel is matched with a fastening constructional element so as to be convenient to be reliably anchored with an end part, thereby solving the problems that the existing steel bar end is difficult to connect and anchor. The steel not only maintains the advantages of a hot rolling product that the tenacity is good, the intensity is high and the production efficiency is high, thereby avoiding the defects that the performance of a secondary cold working product is decreased, the secondary cold working product is brittle and easy to break, a threaded section is short and the processing cost is high; and meanwhile, thesteel has the advantages that the steel is closely matched with the fastening constructional element, and the product self-locking performance is good, the resource waste is effectively avoided in use, thereby saving the used steel quantity.

Description

technical field [0001] The invention relates to geotechnical anchoring and construction engineering technology, in particular to a steel for non-cold working connection. Background technique [0002] In social infrastructure construction, construction projects such as roads, railways, bridges, tunnels, mines, dams, etc. are inseparable from steel, among which various bar steels are indispensable in these infrastructure constructions. Taking mine engineering as an example, the mine roadway is located in a certain geological environment, and the underground rock mass forms various structural surfaces during the long and complex geological movement, which is easy to crack, especially in the middle and late stages of engineering excavation, due to the load change near the working face The redistribution of the stress field is caused, and the structural plane or weak part in the rock mass is moved by the stress, and the small creep evolves into the macroscopic fracture of the roc...

AI Technical Summary

Problems solved by technology

The turning method will reduce the cross-sectional area of ​​the turning part, reduce the bearing capacity, and reduce the overall performance of the rebar; the rolling method will also cause the reduction in the cross-sectional area of ​​the tail thread, reduce the bearing capacity, and easily cause the stress concentration of the steel and poor elongation. When the dynamic load is large, the tail often occurs brittle fracture

No matter what kind of cold working method is used, the overall performance of the rebar will form a bottleneck at the tail thread, and the length of the tail thread section is limited (generally 100mm). , even if the fastening nut is screwed to the end, it cannot contact the rock surface, resulting in anchorage failure

In addition, when multiple steel bars need to be connected and used, it is difficult to realize the connection and use through threaded connection due to the difference in pitch between the head and the tail of the rebar.

Images