Slide 1

Testing of Concrete Poles

Created by,V.P.R. Ariyadasa,SE (Mannar),Uthuru Wasanthaya Project,CEB.

Why pole testing is important?It ensures the protection of workers.

It ensures the protection of equipments.

To ensure the survival of power line for considerable time.

Types of poles6m / 50kg8.3m / 100kg , 8.3m / 500kg 9m / 115kg10m / 225kg11m / 350kg , 11m / 500kg , 11m / 850kg , 11m / 1200kg13m / 500kg , 13m / 850kg , 13m / 1200kg

Testing of poles part IVisual InspectionIn the pole manufacturing yard we must inspect.. The molder.The steel bars. ( brand, the place of piling, galvanized or not..)The method of water treatment. The portion of cement, sand & metal in the mixture, ext. In the pole yard we must inspect.The finishing of poles. ( smoothness, cracks appear or not..)The way of piling. The embossment of marks. Other important issues such as whether the steel bar ends are covered or not by cement in PS poles, etc. Visual Inspection conts The markings of the pole should consist of,Letters CEBSize & working loadDate of castingSerial numberIdentification of the manufacturer. But in some places..

Visual Inspection conts In the pole testing bench we must inspectThe type of bench. ( wooden or steel)Whether the correct pole is brought for testing as requested. The sliding roll mechanism. The method of tensioning & measuring.The place of bench arrangement.The tape arrangement & the indicator.To measure the deflection.To measure the crack position.The hole size & the positioning. Testing of poles part IIApply load, measure the deflection & crack positions

Where to apply the load? Apply load, measure the deflection & crack positions conts How to apply the load..?

Apply load, measure the deflection & crack positions conts Steps of applying the load :-Consider the ultimate load as 2.5 (safety factor) of the ultimate load. Test load shall be applied & raised in increments of 10% of the ultimate load.Load upto 40% of ultimate load and unload fully.Load upto 60% of ultimate load and unload fully.Load till the pole is broken.Meanwhile measure the deflection (in mm) & check the hair cracks for every loadings. After the loading test finishes, break the pole in 3 places and measure the no. of steel bars, its diameter, spacing between stirrups, etc.

Apply load, measure the deflection & crack positions conts Result using an example.Important in pole testing.. Remember to bring piece of choke before come to the pole testing.Hair cracks appear in the opposite side of the side where the test load is applied.The weights which are used to tension the poles may not accurate.Do not rush to take readings. Take some time to settle after applying a load.Try to get feedback about the contractor before going to the pole testing.Try to go with an experience engineer if its the first pole testing you attend., etc. If the tested pole fails to satisfy the standards.Another pole shall be taken from the same batch to test again.If the second pole fails to satisfy the entire batch shall be rejected.The loss due to rejection of 8.3m / 100kg batch.11,240 x 100= Rs. 1,124,000/=The loss due to rejection of 11m / 350kg batch.30,630 x 100= Rs. 3,063,000/=

In practically..

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