bunkers in the storage section are in- dependent to the main building since these are likely to be heavily loaded all the time. In designing the flour bunkers, there was a lack of design in- formation concerning the properties of wheat flour. Accordingly, the soils laboratory of the University of Hong Kong was asked to carry out tests to determine the angle of internal fric- tion, the coefficient of friction between flour and concrete, and the density, which were used in the design.
Construction
All piles were driven by Messrs. Franki Piling & Engineering (Hong Kong) Ltd. to the Consulting En- gineer's design. There were 176 piles of 2011⁄2 in. for the mill and storage blocks and 287 piles of 231⁄2 in. for the silo and cleaning blocks. The penetration per last ten blows, with 3 tons and 414 tons hammers respectively and 6 ft. drops. was less than 34 in.
Be-
To accelerate silo construction work it was decided that slipform was to be used. Made up in advance, the slipforms were of steel plate bolt- ed together to form the shape. cause the concrete must be exposed while green to ensure the proper finish. the height of this type of form is limited to 3 ft. 6 in. and 4 ft. 0 in. The forms were aligned and jacks and yokes set together with the hy- draulic system used for raising the forms. With this system, all jacks are raised simultaneously from a central pumping station, and levelling is automatic.
The whole slipform platform was a three decked type covering the whole area. Concrete, delivered to the site in Ready-Mix trucks was hoisted to the uppermost platform, then tran- sported by wheelbarrows and poured down to the middle platform by means of chutes. Fixing reinforce- ment and casting concrete were per- formed on the middle platform while the finishing and curing were carried out at the lower platform.
Since this method of construction was new to Hong Kong at that time, especially when used on such a large project, attention was paid during the whole construction period. As a result the work was carried out successfully and the silos reached their full height in 150 working hours. The total pour to the silos was about 3200 cu. yds. placed at the rate of 22 cu. yds. per hour.
Clients: Hong Kong Food Pro- ducts Manufacturing Ltd.
Architects: L.V. Hua in associa-
tion with H.M. Chau.
Consulting Engineers:
Pun & Associates.
Main Contractor:
Construction Co.
Peter Y.S.
Chang Tai
Milling machinery supplier and erection: Ocrim, Italy.
Slipform sub-contractors: Concrete Silos Pty Ltd and Walker (HK) Ltd. Ready Mixed Concrete Supplier: Pioneer Concrete (HK) Ltd.
Far East Architect & Builder January, 1967
Slipform in operation on partly completed silos
Completed silos
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