similar fraction greater than 70%.
Remoulded samples of the various types of soil were also prepared at different densities and moisture con- tents and CBR tests were carried out. An examination of the results of the preliminary tests on the soils to be used as fill material indicated that the safe value which could be adopted for the design of the pavements was a compacted subgrade value of CBR of approximately 10% and this value was adopted.
The CBR value of 10% was adopt- ed after carefully considering the various CBRs and moisture contents. In weighing up the various tests it was reasoned that since the 1.c.n. rating of the runway would be taken as the arithmetic mean of the 1.c.n. values less one standard deviation, this cri- terion should also be applied to the choice of CBR.
When this was done it was observed that there was little difference between the soaked and unsoaked CBR values. It was also similarly observed that the in situ moisture content appro- ximated to the moisture content of the soaked CBR samples and also to the plasticity index of the soils. This same pattern was later observed in the tests carried out in situ and in the laboratory during construction. These tests also confirmed that the choice of CBR 10 for design purposes was rea- sonable.
Similar soils to the ones on the air- port site had been encountered during construction of the Kuala Lumpur to Klang highway and it was known that they could be compacted to 95% B.S. heavy compaction and this value was specified for the compaction of soils under paved areas on the airport site. The construction of a trial compaction area was required, however, by the specification for earthworks. Fill un- der areas to be grassed had in most cases only to be compacted to the original in situ density.
Since the in situ density was con- siderably lower than 95% B.S. heavy compaction, an allowance was made in the bill of quantities for overcutting and recompacting in cut areas under the pavement.
The specification also called for proof rolling of the finished formation by a heavy roller, the choice of which was left to the contractor but which had to exert an intensity of vertical stress on the foundation of 150% of the design stress.
Tests had also been carried out on these soils to assess for design pur- poses the amount of lime which would be needed to stabilize them successful- ly. This information was then written into the specification and the con- tractor based his tender for this part of the works on the percentage quoted.
Pavements
Various types of construction were considered for the several pavements and when all aspects of construction and cost had been examined it was decided to adopt a flexible pavement
with a bitumen-bound base for the runway, taxiways and parking aprons, and a stabilized soil base with a bitu- minous wearing surface for all other pavements.
The bitumen-bound base form of construction was adopted since it was estimated that in order to construct pavements with an l.c.n. of 100 it was only necessary to construct them to a depth of approximately 16 in. It was also estimated that such a form of construction could be built at a fairly low cost since experiments had
Fig. 1. General layout
shown that mining sand, which was available cheaply and in very large quantities from several mines adjacent to the site, could be incorporated to a large extent in the mix. It was also reasoned that this form of construc- tion could be carried out in all but the most inclement weather.
A stabilized soil base and bitumin- ous binder or base course and wearing course would probably have been the cheapest form of construction but was not adopted on account of the con- siderable delays which would have
Aircraft landing control lights
-Airfield lighting sub-station
Z
Scale of feet
0
1000
2000
-Airfield lighting
sub-station
Aircraft landing control lights
+Aircraft runway
1
I
-Aircraft taxiway
Aircraft sewage disposal unit
†Parking - fire engines
-Fire station and disaster ward
Meteorological station Telecommunications station
Future highway
→Cable tunnel
Maintenance apron P.W.D. store and nursery Qantas and M. A. L.
C.E.B. sub station
inflammable stores
Malaysian airways future hangar
Bulk fuel storage depot ¡Private hangar
"Bulk fuel storage depot
+Isolation ward
Veterinary dept. etc. and Surau Freight building
Aircraft parking apron
Operation tower
Terminal building
Cooling tower
Car park ~Ceremonial stand
Aircraft parking apron
Future extension to terminal building
·Future extension to aircraft parking apron
To staff quarters
Kuala Lumpur
56
55
Far East Architect & Builder May, 1967