1×2结构钢绞线拉伸试验方法改进

Improvement of tensile test method of 1 × 2 structure steel strand

1×2结构低松弛预应力钢绞线采用常规的钢绞线拉伸试验成功率低,且存在较大误差。试验成功率低的原因在于牙板与钢绞线之间的不匹配,现有牙板主要有V形牙板和平板形牙板,对1×2结构钢绞线产品均存在局限性。将拉伸试验中试样两端V形牙板内的1×2结构钢绞线填充为1×3结构,可保证试件与牙板更好的配合,使整束钢绞线最大力值明显高于改进前所得力值,试验数据准确性更高。

The success rate of 1 × 2 structure low relaxation prestressed steel strand adopted with common steel strand tensile test is very low, and the result has big error. The reason of the low success rate is mismatching between tooth board and steel strand. Existing tooth board has V-type tooth board and flat-type tooth board, which have the limitation of 1 ×2 structure steel strand product. In tensile test, change specimen both ends 1×2 structure steel strand into 1 × 3 structure steel strand in V-type tooth board, and ensure the matching of specimen and tooth board, the maximum force value of whole bundle steel strand is obviously higher than force value before improvement, the accuracy of test data is higher.