Appraisal Background
Rebar is the common name for hot-rolled ribbed steel bars. The grade of ordinary hot-rolled steel bars consists of HRB and the minimum yield point of the grade. Rebar is a necessary steel material for medium-sized and above building components, which profoundly affects the quality and safety of buildings. The nominal diameter range of
steel bars is 6~50mm. The standard recommended nominal diameters of steel bars are 6, 8, 10, 12, 14, 16, 20, 25, 32, 40, 50mm.
Zhongke Testing can carry out material product quality appraisal services, carry out appraisal work on whether there are quality problems related to rebar, issue professional and reliable inspection reports, and assist courts and enterprises in resolving product quality disputes.
Basis for appraisal
SN/T 3468.4-2013 Steel damage inspection and identification procedures Part 4: Rebar and wire rod
GB/T 20065-2016 Rebar for prestressed concrete
JT/T 1265-2019 Method for testing the tension of prestressed precision-rolled rebar for bridges
HB 7180-1995 Welded steel tie rod threaded connection assembly
GB/T 26120-2010 Low pressure stainless steel threaded pipe fittings
Authentication case
A construction company contracted a yard construction project and purchased a batch of steel bars from a building materials company and put them into construction. Soon after, the Quality Supervision Bureau determined that the batch of steel bars was unqualified during a random inspection and ordered the construction company to repurchase steel bars and dismantle the constructed parts. This caused time and economic losses to the construction company, so the building materials company was sued to court and our company was entrusted to conduct quality appraisal of this batch of threaded steel bars.
The expert group randomly selected 60 pieces of each of the two models of steel bars involved and measured them separately in accordance with GB 1499.2-2018. They found that the average nominal diameter of the two models was lower than the standard and the theoretical weight was also lower than the standard allowable deviation.
In other words, this batch of threaded steel bars does not meet the requirements of national standards and is a substandard product.
