Demoulding 75 placing compaction b by providing two

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Unformatted text preview: 2 15 mm from top and 1SO mm belou ground level (see Fig. 1) to enable 25 mm x 3 mm copper strip or equivalent bare copper cable to be taken from the top hole to the bottom through the central hole. and Curing of Concrete 7.5.1 The concrete shall be used as soon as possible after being mixed and no material which has developed an initial set shall be used in the work. After the concrete has been placed in the moulds and compacted, it shall not be disturbed during the period of setting. For depositing concrete in hot weather, IS 786 1 (Part 1) may be referred. 7.8.2 The purchaser shall specify the type of earthing to be provided. 7.9 Holes 7.5.2 Compacting During manufacture, sufficient holes shall be provided in the poles for the attachment of cross arms and other equipment. A typical arrangement of holes shown in Fig. 1 permits the use of reinforced concrete poles in conjunction with wood or steel cross arms. but other arrangements may be specified by the user. Holes for kicking block may be provided. if necessary. Concrete shall be compacted by spinning, vibrating, shocking or other suitable mechanical means. Hand compaction shall not be permitted. 7.5.3 Curing After placing, the concrete shall be adequately protected, during setting and in the first stages of hardening, from shocks, running or surface water and the harmful effects of sunshine, drying winds and cold. The concrete shall be cured for at least 28 days unless special curing methods are adopted, in such cases it shall be cured till the required strength is achieved. Steam curing of concrete may be adopted if so desired by the manufacturer provided the requirements of pressure or non-pressure steam curing are fulfilled. 7.6 7.10 Eye Hook To facilitate handling of poles during transport and erection, an eyehook may be provided suitably in every pole below ground level on the face of the poles so as to utilize the maximum flexural strength of the section during handling. 8 TESTS 8.1 Transverse Finish Strength Test The transverse strength test of reinforced concrete poles shall be conducted in accordance with IS 2905. A reinforced concrete pole shall be deemed not to have passed the test if the observed ultimate transverse load is less than the design ultimate transverse load. The concrete when removed from the mould shall be of good finish and free from honeycombing. All arrises shall be clean and true and shall present a neat appearance. 7.7 Tests on Concrete During manufacture, test on concrete shall be carried out as specified in IS 456. The manufacturer shall supply when required by the purchaser of his representative, results of compressive test on concrete cylinders or cubes made from the concrete used for the poles. If the purchaser so desires, the manufacturer shall supply cylinders or cubes for test purposes and such cylinders or cubes shall be tested in accordance with IS 5 16 . 9 SAMPLING AND INSPECTION 9.1 Scale of Sampling 9.1.1 Lot In a consignment of 500 poles or a part the...
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This document was uploaded on 10/01/2013.

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