DYWIDAG Threadbars are stressed using compact lightweight hydraulic jacks. In most cases handled by one man, the jack fits over a pull rod designed to thread over the THREADBAR® protruding from the anchor nut. The jack nose contains a socket wrench and ratchet device which allow the nut to be tightened as the THREADBAR® elongates. 1-3/4 and 2-1/2 bars utilize specially equipped center-hole stressing jacks. The magnitude of the prestressing force applied is monitored by reading the hydraulic gauge pressure and by measuring the THREADBAR® elongation. The elongation can be measured directly by noting the change in THREADBAR® protusion.
|1 Bar size||in||58||1,|
|1||mm||15||26, 32||32, 36||46||66|
|1 in. c||in||24||26||30||36||43|
*) This system should have a mechanical means of lifting and moving.
**) Special nose extensions for deep stressing pockets are available on request.
Note: Detailed operating and safety instructions are provided with all stressing and grouting units. Read and understand these instructions before operating equipment.
Grouting completes the installation process for post-tensioned concrete construction.The grout is important in protecting the steel from corrosion and contributes significantly to the ultimate strength of the structure. After mixing, the grout is injected into a low point vent until consistent material is exhausted at the terminating or anchorage vent. An admixture may be used to control expansion and pumpability.