1. In order to ensure that the theoretical elongation value and the actual elongation value are within the specified range, additional friction must be reduced to ensure that the corrugated pipe posit...
The duct grouting
1. Mixing of cement slurry: the pore pressure slurry is pure cement, the water-cement ratio is 0.40 ~ 0.45 and the consistency is controlled between 14 ~ 18s, the bleeding rate is controlled within 3%...
Stretching operation procedure
1. Tensioning sequence of steel strand bundles: after the concrete strength reaches 85% of the designed value, the tensioning will start. According to the principle of first stretching close to the st...
Preparations for tension
1. Calculate the theoretical elongation value of the steel strand: the tension is conducted by the method of controlling the stress and elongation with double control and upper arch degree check, and ...
At present, there are some problems in the prestressed construction technology of road and bridge engineering
1. Bellows are blocked. Plugging pipe refers to the phenomenon that the corrugated pipe becomes blocked after concrete casting, which will result in the failure of the later prestressed steel strand t...
Prestressed post tensioning method
The prestressed post-tensioning method refers to making components first and setting aside a corresponding channel in the member body according to the position of prestressed reinforcement. After the ...