Monostrand Post-Tensioning System
An open throat, twin ram jack for stressing 0.5 (12.7 mm) or 0.6 (15.2 mm) single strand is suitable for stressing at tendon ends or at intermediate tendon anchors.
For tendon elongation greater than the stroke of the jack, the wedges are temporarily seated after partial stressing and the jack is recycled.
There are many stressing systems available from DYWIDAG. To obtain drawings of a system best suited for your particular project, contact your DYWIDAG representative.
Note: Detailed operating and safety instructions are provided with all stressing units. Read and understand these instructions before operating the equipment.
Tendons may be placed in bands or in a uniform distribution depending upon the structural requirements.
DYWIDAG Tendons are cut to length, marked, coiled, and tagged for ease of handling and identifying in the field.
Steel Stress Level
Where required, strands are stressed to the maximum jacking levels shown. These are temporary forces applied to the strand to overcome friction losses. Maximum jacking forces must not be exceeded. After the wedges are seated, the stresses at anchorage or coupler locations shall not exceed anchorage values shown, while the maximum force in the entire strand shall be less than anchorage force given in the table.
The average final forces after all losses for typical installations are noted as effective forces. These values can be calculated more accurately for each project by the design engineers or DYWIDAG considering interactive time-depending losses: concrete shrinkage, creep, and steel stress relaxation.