热轧带肋钢筋的力学性能随时间变化而变化的特点使得企业检验出的力学性能与用户检验出的存在差异。为找出热轧带肋钢筋不同时间段力学性能的变化特点，对热轧带肋钢筋不同时间段的力学性能进行了试验。结果表明：10 d（天）内热轧带肋钢筋的各项力学性能指标变化最快，20 d后各项力学性能指标趋于稳定；其变化规律为屈服强度降低，抗拉强度、断后伸长率、最大力下总伸长率升高；屈服强度降低最多为17.31 MPa，建议企业制定内控标准时屈服强度应比国标高20 MPa。

The mechanical properties of hot rolled ribbed steel bars change with time, which makes the mechanical properties tested by manufacturer different from those tested by consumers. In order to find out the change characteristics of mechanical properties of hot rolled ribbed steel bars in different time periods, the mechanical properties of hot rolled ribbed steel bars in different time periods were tested. The results show that the mechanical properties of hot rolled ribbed steel bars changed rapidly within 10 d (days), and tend to be stable after 20 d. The change rule is that the yield strength decreased, the tensile strength, the elongation after breaking and the total elongation under maximum force increased. The yield strength decreased by 17.31 MPa at most. It is suggested that the yield strength should be 20 MPa higher than GB when enterprises formulate internal control standard.