Construction of reinforcing steel construction steel descaling in the specification is how to provide?

1, the surface of the rebar should be clean, before use should be the surface oil stains, paint stains, rust, scale rust, etc. clean, but the surface of the rebar water rust and color rust can not do special treatment. In the process of steel cleaning and descaling or after descaling, when the steel surface is found to have serious corrosion, pockmarks, spots and other phenomena, it should be identified as damage to determine the degradation of the use of or removal of unused.

2, rebar should be straight, no local bending, rebar centerline deviation from the straight line should not exceed 1% of its full length. Plate of steel or bent steel should be straightened before allowing the use. The straightened rebar shall not have dead bends, otherwise it shall be rejected. If the rebar is found to have splitting phenomenon after straightening, it shall be treated as scrap and the quality of the batch of rebar shall be identified. After straightening the steel bar on the straightening machine, its surface shall not have obvious scars.

3, the straightening of steel bar should be straightened by mechanical straightening and cold drawing method. For a small amount of thick steel; when there is no mechanical straightening and cold drawing straightening conditions, can be used manually straightening. If the cold drawing method straightening, the straightening cold drawing elongation should not be greater than 1%. For 1 level of steel, in order to be able to straighten the cold drawing at the same time to remove the rust skin, may be appropriate to increase the cold drawing rate, but the cold drawing rate shall not be greater than 2%.

Manual and power descaling: indicated by the letter "St", divided into two grades:

St2 thorough manual and power descaling. The surface of the steel is free from visible grease and dirt, and free from poorly adhered adherents such as oxidized skin, rust and paint coatings.

St3 Very thorough manual and power descaling. The steel surface should be free of visible grease, dirt. It should also be free of poorly adhered adherents such as oxidized skin, rust and paint coatings. Rust removal is more thorough than St2, and the surface of the exposed portion of the substrate should have a metallic luster.

Reference: Baidu Encyclopedia-Steel Descaling