Method

STANDARD METHOD OF TEST FOR CONSISTENCE OF CONCRETE

The test is to be used both in the laboratory and during the progress of the work for determining the consistence of concrete.

The test specimen shall be formed in a mould in the forms of the frustum of a cone with internal dimensions as follows.

Bottom diameter 8 inches, top diameter, 4 inches and height, 12 inches. The bottom and top of the mould shall be open and at right angles to the axis of the cone. The mould shall be provided with suitable foot-pieces and handles. The internal surface shall be smooth.

Care shall be taken to ensure that a representative sample is taken.

The internal surface of the mould shall be thoroughly clean, dry and free from set cement before commencing the test.

The mould shall be placed on a smooth, flat, non-absorbent surface, and the operator shall hold the mould firmly in place, while it is being filled,’ by standing on the foot-pieces.

The mould shall be filled, to about one-fourth of its height with the concrete, which shall then be puddled using 25 strockes of a 5/8 inch rod 2 ft. long, bullet-pointed at the lower end. The filling shall be completed in successive layers similar to the first, and the top struck off so that the mould is exactly filled. The mould shall then be removed by raising vertically, immediately after filling. The moulded concrete shall then be allowed to subside and the height of the specimen measured after corning to rest.

The consistence shall be recorded in terms of inches of subsidence of the specimen during the test, which shall be known as the slump.

RCC LIGHTING POLES SPECIFICATION

We manufacture poles by a most modern method in which the concrete is compacted by all known methods of vibration, compaction and centrifugation. The reinforcing steel bars are pretensioned in order to keep them in correct aligned position and thus ensure a uniform cover of 3/4″ to prevent any cerro­sive effect.

We give below physical characteristics of a 30 ft. pole which when tested withstood a transverse load of 1250 lb. with a percentage equivalent of working load of 300 lbs and a maximum deflection of 8″ with permanent set of 1/2″ on removal of load.

Length…………………………30 ft.
Section………………………..Octagonal Tapered
Bottom…………………………13″ across flats
T
op………………………………6″ across flats
Hollow…………………………..8″ – 4″ tapered
Steel…………………………….1/2″ dia, 8 bars
Weight………………………….13 cwt approx.

As regards other sizes i.e. from 12 ft. to 36 ft. length poles dimensions and strength will vary in proportion to that of the 30 ft. standard pole.