What is the allowable distance between GPW welds?

Ga pressure welding of rebar is one of the new methods for connecting construction rebars in Iran, which has been studied by the Building and Housing Research Center since 2009 and implemented and implemented by Structural Test Steel Engineering Company as the founder of this technology in Iran.

This technology, which is a much safer and more acceptable alternative to the old overlap method and even mechanical connections, is very simple and efficient. In this welding process, like all other welding methods, the edges of the welded parts, which in this case are two rebars, must first be cut smoothly by a cold cutting machine or a special rebar cutter and zero degrees. Note that this cutting must be done by a special machine made for GPW, and any cutting with other tools such as guillotine, iron cutter and milling stone is completely prohibited and will cause failure and failure of welding in the future.

A very important point in this method is the execution of gas pressure welding work by trained people and has a certificate of gas pressure welding skills. Because this method is a semi-automatic and manual process, so like all other welding methods, the welding forging operator must have a certificate of skill and certification of the welder. This certificate must be issued by technical and vocational training centers or companies with specialized welding engineering schools in the field of GPW, such as structural test steel engineering company. Lack of welding certificate and certification ofgas pressure welding operator will undoubtedly lead to incorrect execution and non-observance of small details of the work and the occurrence of serious human and financial disasters in the future.

Unfortunately, it is seen in many construction and construction projects that due to the lack of the same skill of the GPW operator and the lack of welding certification, serious and dangerous mistakes are made in the projects. One of these mistakes is not observing the distance of welds performed in a section such as column or shear wall or foundation.

According to the paragraph mentioned in the special criteria for design against earthquakes in the ninth article of the National Regulations of the National Building of Iran, welding patches are allowed provided that the rebar is patched on each rebar table one by one and the patch spacing is adjacent to adjacent rebars. The length of the member should not be less than 60 cm

Of course, this amount is suggested in the regulations and authorities of Japan, which is the main birthplace of gas pressure welding of rebar technology, 40 cm. Therefore, according to the conditions prevailing in Iranian projects such as design and calculation of engineers, rebar production process in Iran, material and strength and mechanical properties of rebars in Iran, gas consumption conditions and expertise of the rebar welding operator, etc. are suggested with A more desirable calculator, designer, and supervisor should be selected to ensure both strength and the extra rebar is not left out of the project.