HINTON EF
BORES
IMPECTOR DI
-་
WORKS.
GENE
CEY
BALANCE
BOOM
FOREHAN
STORES OFFICE
WCE 1
WORKS
STORLE
PORT
BITUMINOUS MATERIAL
TESTING ROOM
Benches, wall cases,
SAMPLE ROC
1705,
TESTING
CONCRETE
TESTING
1
FORES
AGGREGATE
1
STORES
(Above) (Ground floor plan.
(Left) Upper floor plan.
than the shear test mentioned above, but it takes much longer to do— approximately a week, and this ap- paratus is not used unless the data required is of considerable importance.
Another piece of apparatus, called the unconfined compression testing machine, does work somewhat similar to that of the triaxial machine. It is, moreover, suitable for field work and tests can be carried out on it very much more quickly.
The standard compaction appara- tus determines the maximum density obtainable from a soil sample for a given amount of water content.
By means of what is known as the California bearing ratio test appara- tus, the load that the soil can carry is determined by a visual gauge, and it is this machine that provides data from which the thickness of pave- ment required to carry any designated load may be calculated.
Another important function of soil determination tests is connected with the building of earth dams, for con- instance the one at Tai Lam Chung. and for this purpose the aqueous permeability tester or variable head permeator is used to determine the nature of the soil under artificial and natural conditions.
sinks, and pression tests includes a very efficient sample cabinets are provided where vibrator, which thoroughly required. Other provisions and fix- solidates the material. tures built in, not including testing equipment itself, are fume cupboards. waste chute, damp chamber and six curing tanks.
3. BITUMINOUS MATERIAL
TESTING
The major part of the work done in this room is the testing of tarmac The design for the Port Works or tartops prepared in the govern- All soil, regardless of the tests to be Depot & F.W.D. Laboratory was pre- ment quarries for use on new roads made on it, goes through routine or pared by the Architectural Office of or repairing existing roads. These classification examinations, which fix the Public Works Department. The materials are regularly submitted for the liquid limit first and then the general contractors were Lap Hing & testing in order to insure that the plastic limit. The grading of soil that Co., metal windows were supplied by quality of materials and percentage is too fine to be done on ordinary the China Steel Works Ltd.. electrical of bitumen content is constant. The sieves is carried out by means of the installation was by Golden Gate Co., apparatus in this room includes those hydrometer test. and the felt membrane roofing by required to determine the penetra- Shewan, Tomes & Co., Ltd.
tion, specific gravity, softening point, tests are being carried out with the At the present time, consolidation bitumen, fire It might be of interest to review percentage of pure
machine on hand, but it is expected briefly the work carried out in the point, and viscosity.
that new machines will be arriving laboratory. The activities are divided The number of tests carried out in soon with which more accurate data roughly into five sections:
this room is not large at the present can be obtained. From consolidation time as the apparatus has only re- tests, data is obtained regarding the cently been installed, but it is expect- settlement of soil, from which it is Six-inch concrete cubes, when sub- ed that increasing use will be made possible to predict the time required Work is for soil to consolidate completely and mitted to the laboratory, are first of the facilities available. seasoned in water tanks before the somewhat hampered in this depart- safely carry foundation loads.
ment owing to the fact that no gas actual test is carried out. The
There is a sample room in the has yet been installed, the heating laboratory, in which specimens are machine on which the cubes are tested for strength in compression has having to be done by electricity or kept after testing for future reference. a capacity of 150 tons and is operated alcohol burner which is not quite as An interesting collection in this room
1. CONCRETE TESTING
hydraulically.
convenient.
4. SOIL TESTING
is of samples of earth and cement mixtures made up in the laboratory, which withstand considerable com- pressive stresses.
Apparatus is also available to carry out slump and contraction tests when In this section is carried out pro- required. Adequate facilities exist bably the most important work of the for carrying out tests on the aggre- laboratory and it is the only one in 5. gates, as well as on the concrete, and Hong Kong able to undertake this all results are compared with the work. Here the properties of the soil
BRICK AND TIMBER TESTING
With the available resources it is
British Standard Specifications gov- are analysed, from which various possible for the laboratory to carry
erning such materials.
2. CEMENT TESTING
calculations are made and its value out tests on bricks and reports have determined, particularly for load been issued on the strength, per- bearing purposes, filling for reclama- meability and other physical charac- tion work, etc.
teristics of samples of this product Cement is tested for its physical
sent for testing. Most tests on timber properties and not for its chemical The angle of internal friction and are made by the Forestry Department, content, which latter work is done by unit cohesion of the soil particles is but certain types of tests on this the Government Analyst and is not tested on a box shear apparatus. The material are carried out in the duplicated in this laboratory. This triaxial compression testing machine laboratory. section is able to carry out tests for confines the material being tested, tensile strength, compressive strength, subjects it to lateral pressure, and Mr. F. H. Chen, who is a specialist setting time, soundness, and fineness. applies a vertical load at the same in soil mechanics. is the superinten- The machine carrying out the com- time. This is a more accurate test dent in charge of the laboratory.
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