March_1966 — Page 73

crushed) graded to a maximum of % in. was used with fines of the same material and white Portland cement; the water/cement ratio was 0.35 to 0.37. The specified cube strength of 6,000 lb. per sq. in. was greatly ex- ceeded, with 28-day strengths normal- ly in the range of 9,000 to 10,000 lb. per sq. in.

This aggregate was exposed by washing and acid-etching; the method of treatment and the age at which this was carried out depended upon the particular unit.

Modular Pattern

In developing the site great atten- tion was paid to retaining its rural character. An effort was made to eliminate extraneous building and emphasis was given to flat roof de- sign,

Plant rooms were placed in the basement; hydraulic lifts were used to avoid high level motor rooms; the use of two types of fuel for the boil- er plant enabled the chimney to be blended into the building, after dis- cussion with the planning authorities.

Cooling towers for air conditioning, water storage tanks and transformers are grouped in a walled service com- pound and designed in such a way that they are not seen and do not de- tract from the overall simplicity of the development. The two buildings, research and administration, are connected by an underground passage and there are no covered ways on the site.

Externally, similar principles have been applied. Across the centre of the site ha-has have been used instead of fences to control the cattle which are grazed over 28 acres of pasture by a tenant farmer.

are

The two buildings, designed on a 4 ft. 8 in. modular pattern, are similar in architectural character and sited so as to complement each other. Their total floor area is 125,000 sq. ft. Each building has two floors above the general level of the surrounding ground, and one partially below. The latter contains the accommodation for which an outlook is least necessary.

The reinforced concrete frame with its granite aggregate has a roughish texture. Glass cladding walls are set back some 5 ft. from the edge of the building, and the glazing is in grey sheet glass to reduce glare inside and to give a warm appearance against the anodised aluminium mullions out- side.

The administration building mea- sures 200 ft. by 160 ft. and accom- modates 450 people. Visitors coming in by the main entrance reception hall through revolving doors see across a large open court which contains a reflecting pool.

Staircases, toilet accommodation and local coat hanging spaces are concentrated in central cores on either side of the court. The large general offices on the two upper floors

Far East Architect & Builder March, 1966

Centre court and reflecting pool

face the inner court and the perimeter offices look out on to the park.

The research building in which over 100 people work measures 160 ft. by 108 ft. Again, there are plant rooms. cloakrooms, etc.. on the ground floor. The main plant room serving both buildings is also here, though there are two additional plant rooms for ventilation in the adminis- tration building. Both buildings are fully air-conditioned. There is court in this building but ground floor there are conference rooms, furniture and stationery stores and a health department. The two upper floors contain all research and experimental departments.

Floors

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The ground floors are generally ap- proximately 8 ft. below the surround- ing ground level. The concrete for the floors and walls was placed in al- ternate bays, with p.v.c. waterstops in the construction joints and around the column bases. No bituminous membrane has been provided and re- liance for waterproofing is placed up- on the well compacted concrete with an underlay of 0.006 in. polythene sheeting.

On the first and second floors the vertical members of the external frames and the internal columns are positioned on a 28 ft. by 23 ft. 4 in. grid. The internal columns are gen- erally cast in situ but a small num- ber in the entrance and canteen areas of the ground floor are precast.

Conventional flat slab floors have been adopted to provide maximum freedom for service runs and air ducts. The slab is generally 9 in. thick, increasing to 15 in. in the drop- ped panels around the columns. The only exception to this is in the prin-

cipal floor to the research block which has been designed for a maximum superimposed loading of 300 lb. per sq. ft; here, the thickness of the floor slab has been increased to 12 in. with 18 in. drop panels.

Services

The design and installation of all the mechanical and electrical services was under a multi-services contract.

The office areas of the administra- tion building have comfort conditions maintained by a high velocity induc- tion type air-conditioning system, the units of which are located beneath the cills of the windows facing the inner court, and the external perimeter of the building. Internal areas are serv- ed by separate air-conditioning units.

Lighting of the perimeter offices is by tungsten type fittings recessed in- to the acoustic tile ceilings, and an illuminated ceiling has been installed in the general office areas. The can- teen is served by a separate air-condi- tioning system, and illuminated by tungsten fittings as used in the peri- meter offices.

To maintain comfort conditions in the laboratories of the research build- ing a high-pressure, high velocity dual duct air conditioning system has been installed and air distribution from this and other air-conditioning and ventilation systems has been integrat- ed with the fluorescent lighting fittings by developing a special combined unit especially for this project and the first full-scale introduction in the United Kingdom of a ceiling type air diffuser was made in this unit.

Full co-ordination of the services during both design and installation was a key feature of the contract and has resulted in considerable savings in space and installation time and cost.

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