Specification Part 3 - Road & Bridge Works - Urban Administration ...

1802.2.3. In severe environment, cables shall be threaded after concreting. In such cases a
temporary tendon shall be inserted in the sheathing or the sheathing shall be stiffened by other
suitable method during concreting.
1802.3. Apchorages
1802.3.1. Anchorages shall be procured from authorized manufacturers only. Anchorages shall
conform to BS: 4447. Test certificates from a laboratory fully equipped to carry out the tests shall
be furnished to the Engineer in charge. Such test certificates shall not be more than 12 months
old at the time of making the proposal for adoption of a particular system for the project.
No damaged anchorages shall be used. Steel parts shall be protected from corrosion at
all times. Threaded parts shall be protected by greased wrappings and tapped holes shall be
protected by suitable plugs until used. The anchorage components shall be kept free from mortar
and loose rust and any other deleterious coaling.
1802.3.2. Swages of prestressing stand and button-heads of prestressing wire, where provided
shall develop strength of at least. 95 per cent of the specified breaking load of the strand or wire
as the case may be. Where swaging/button -heading is envisaged, the Contractor shall furnish
details of his methodology and obtain approval of the Engineer in charge, prior to his taking up
the work.
1802.3.3. Untensioned Steel reinforcements, around anchorages shall conform to the details of
prestressing system and as shown on the drawing.
1803. TESTING OF PRESTRESSING STEEL AND ANCHORAGES
All materials specified for testing shall be furnished free of cost and shall be delivered in
time for tests to be made well in advance of anticipated time of use.
All wire, strand or bars to be shipped to the site shall be assigned a lot number and
tagged for identification purposes. Anchorage assemblies to be shipped shall be like-wise
identified.
All samples submitted shall be representative of the lot to be furnished and in the case of
wire or strand, shall be taken from the same master roll. The Contractor shall furnish samples of
at least 5.0 m length selected from each lot for testing. Also, two anchorage assemblies complete
with distribution plates of each size or types1 to be used shall be furnished along with short
lengths of strands as required.
1804 WORKMANSHIP
1804.1. Cleaning
Tendons shall be free from loose rust, oil, grease, tar, paint, mud or any other delet erious
substance. Cleaning of the steel may be carried out by immersion in suitable solvent solutions,
wire brushing or passing through a pressure box containing carborundum powder. However, the
tendons shall not be brought to a polished condition.
1804.2. Straightening
High tensile steel wire and strand shall be supplied in coils of sufficiently large diameter such that
tendons shall retain their physical properties and shall be straight as it unwinds from the coil.
Tendons of any type that are damaged, kinked or bent shall not be used.
The packing of presuessing wire/strand shall be removed only just prior to making of
cable for placement. Suitable stands shall be provided to facilitate uncoiling of ires/strands
without damage to steel. Care shall be taken to avoid the possibility of steel coming into contact
with the ground.