CONCRETE PERMEABILITY TESTER - AS PER IRS CONCRETE BRIDGE CODE WITH COMPRESSOR

CONCRETE PERMEABILITY TESTER - As Per IRS Concrete Bridge Code : 1997(APPENDIX –G)

The apparatus consist of

Permeability Cell : 3 Nos.

The permeability cell will consist of a non corrodible metal cylinder for holding the specimen of 200mm dia X 120mm high. A rubber or neoprene O-ring or other suitable gasket, seated in matching grooves will be used between the cell and the cover plate to render the joint water-tight.

Water Reservoir

A suitable reservoir consist of a length of metal pipe, 50 to 100 mm in diameter and about 500 mm long. The reservoir will be fitted with a graduated side arm gauge-glass, and the necessary fittings and valves for admitting water and compressed air and for draining, bleeding and connection to the permeability cell.

Procedure

(a) Preparation of Test Specimen

Test specimen of 200 mm diameter and 120 mm thick to be used. After 24 hours of casting of specimen, central circular area of 100 mm diameter shall be roughened with a wire brush on the side on which the water pressure is to be applied. The unroughened part of the side of the test specimen which is subjected to water pressure is to be sealed with two coats of cement water paste (W/C = 0.4).

(b) Test Procedure

After 28 days curing, test specimen is fitted into a test apparatus where the water pressure acts on the required face and remaining faces can be observed.

At first, a pressure of 1 Bar is applied for 48 hours, then 3 Bar for next 24 hours and 7 Bar for next 24 hours. The Pressure is applied through an Air Compressor.

After the test, the specimen is split in the middle by the compression applied on two round steel bars lying on opposite sides, above and below. The side after the test specimen exposed to the water pressure should face downwards.

Observation

The average of three maximum values of penetration is calculated. The depth of penetration of water should not be more than 25mm otherwise the specimen are considered to be failed in permeability test

Note : Consumable available at extra cost : Sealing compound : wax and resin extra