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Laboratory Testing
Public Works Laboratories

The Public Works Laboratories (PWL) comprise the Public Works Central Laboratory (PWCL), located in a purpose-built building, at Kowloon Bay, and five Public Works Regional Laboratories, located at Tsz Wan Shan, Tai Po, Tsuen Wan, Tin Shui Wai and North Lantau. The PWL together have around 170 staff, consisting of professionals, technical and clerical staff, some of whom are consultant staff.

The PWL provide an extensive range of materials testing services Download PDF  for the construction industry in Hong Kong. These include the testing of aggregates, bituminous materials, cement, pulverized fuel ash (PFA), concrete cubes and cores, steel reinforcing bars, timber, rubber, soil and rock, in-situ CBR and soil density, building blocks and bricks, concrete kerbs, geotextile, manhole covers and pipes, etc. About 700,000 tests on various construction materials were carried out in 2015. All PWL tests are carried out strictly in accordance with the PWL Quality System, which is subject to third party audits.

Since 1988, the PWL have been accredited by Hong Kong Accreditation Service (HKAS) under the Hong Kong Laboratory Accreditation Scheme (HOKLAS) for most of the tests as well as a range of calibration services. This accreditation assures clients that the quality system of PWL meets the requirements of ISO/IEC17025 and that the test results are verifiable to international standards. Results of all accredited tests are presented on HOKLAS endorsed test certificates and reports.

The PWL perform compliance and investigative testing, together with some research and development work relevant to construction materials and geotechnical technology. A data bank on cement and steel bar is also maintained by the PWL, which is open to all Government Departments and members of the public.

The PWL outsource many of the routine compliance tests of concrete, steel, soil and rock, bituminous materials, chemical tests, etc. to commercial laboratories. To ensure testing quality, the PWL carry out regular audits, surprise surveillance inspections and parallel testing at the contract laboratories.

The testing and calibration services of the PWL are provided mainly to Government projects but the public may also utilise these services by paying a fee (details are given in an Information Brochure on the PWL testing services Download PDF and a Schedule of Fees Download PDF. For enquiries, please call 2305 1290 during office hours.

Soil and Rock Testing

The PWL provide an extensive range of laboratory soil and rock testing to international standards. The most common tests performed are oedometer, direct shear, triaxial, compaction, classification and various types of strength and stress measurement tests.

triaxial testing system The triaxial testing system in the PWL is specially designed. They can be operated manually or automatically, with all the data being logged directly into a computer. The PWL have the capacity to test up to 18 soil specimens simultaneously.

Over and above the traditional testing services that they are set up for, the PWL continue to proactively explore, research and develop new tests in order to meet the needs of Hong Kong's construction industry. Recent examples include impact absorbing test for playground materials, specimen preparation technique for large soil/rock thin sections for petrology, and CERCHAR test for rock tunnelling works, microwave and infrared oven
for determination of moisture content of soil.

Testing the Resilience of Impact Absorbing Playground Surfacing Materials Testing the Resilience of Impact Absorbing Playground Surfacing Materials
Testing the Resilience of Impact Absorbing Playground Surfacing Materials - The energy absorption ability and the critical fall height of playground surfacing materials can be determined by performing a drop test with a precise measurement of the acceleration and time of impact.

Preparation of Large Thin Sections of Rock Preparation of Large Thin Sections of Rock
Preparation of Large Thin Sections of Rock – the PWL acquired the technique of preparing large thin sections (75 mm x 50 mm) of rock.

Stress Path Triaxial Tests Stress Path Triaxial Tests - The Global Digital System apparatus is capable of performing various types of stress path tests for advanced soil testing.
Cerchar Abrasiveness Test - Cerchar scratch test is a test method for assessing rock abrasiveness. Through this test, a parameter named Cerchar Abrasiveness Index (CAI) can be determined, which is particularly useful for hard rock classification and estimation of tool wear rate of tunnel boring machines. Cerchar Abrasiveness Test
Construction Materials Testing

The PWL perform compliance testing of construction materials, such as aggregates, bituminous materials, concrete, cement, PFA, thermoplastic road marking materials, steel reinforcing bars, steel fabric and structural steel sections, as well as steel prestressing wires and strands and other products including clay pavers, paving slabs, interlocking blocks, precast concrete kerbs, timber, rubber, cast iron manhole covers, step irons, recycled plastic fenders, geotextiles and concrete, clay or PVC pipes, and playground surfacing materials. The vast majority of these tests are accredited by HKAS.

PWL To cater for the requirements of the various tests, the PWL are equipped with four Universal Testing Machines with different capacities to cover the testing range from 0.005kN to 2000kN.

The PWL are equipped with eighteen automatic concrete compression machines with capacities up to 3,000 kN, and three flexural testing machines with capacities up to 100 kN. PWL
Chemical Testing

Chemical testing and advisory services related to construction materials are provided by PWL.

The services cover a wide range of areas, including routine chemical compliance testing of construction materials, analysis of the chemical composition of cement and hardened concrete in accordance with international standards, and examination of miscellaneous samples for objectives such as evaluation of quality and causes of failures in performance.

Advances in technology and the introduction of new construction materials and products over the years have necessitated the installation of a number of key scientific instruments in the PWL, including an atomic absorption and emission spectrophotometer, a flame photometer and an ultra-violet / visible light spectrophotometer. Chemical Testing
In-situ Testing Services

In-situ testing services In-situ testing services are provided mainly by the five Regional Laboratories. The tests include in-situ soil density, California Bearing Ratio (CBR), skid resistance of road marking and road surface texture depth and regularity. Besides site testing, laboratory testing services on the properties of sub-base materials, paving blocks, concrete cubes, bituminous materials and aggregates are also available in the Regional Laboratories.
Calibration Services

Calibration services Calibration services can be provided not only to serve the needs of the PWL but also for the public in certain areas upon request. The services provided include calibration of balances, calipers, compression and tensile testing machines, depth gauges, dial gauges, extensometers, feeler gauges, lever arm ratio, load cells, masses, micrometers, ovens, pressure gauges, proving rings, scale rules, stop watches, thermometers, thermocouples, transducers and volumetric apparatus, flatness and surface texture of metal surface plates and skid resistance tester. Many of the calibration services are accredited by HKAS.
Outsourcing and Specialist Lists Management

In order to offer an efficient testing service, some routine compliance tests are outsourced to commercial testing laboratories. They include testing of concrete, steel, bituminous materials, etc. To ensure the quality of the outsourced services, a dedicated team of professional and technical staff is responsible for administering the term contracts for these outsourced tests.

The PWL are responsible for administering term contracts for soil and rock testing, and the technical management of the Development Bureau List of Approved Suppliers of Materials and Specialist Contractors for Public Works in the Soil and Rock Testing Category.

For the selection of laboratories for tendering, two lists, namely the PWL List of Contractors for Concrete Testing Download PDF and the PWL List of Contractors for Reinforcing Steel Testing Download PDF are set-up. For entering into the Lists, interested laboratories will need to submit supporting documents to PWL for assessment. Only high quality and HOKLAS accredited commercial laboratories are included into the Lists.

The performance of the contractors having current contracts with PWL is generally administrated in accordance with the Contractor Management Handbook except specified otherwise.

Quality Management
The Quality Management in the PWL is managed by a team of professional and technical staff. The team is responsible for managing and supervising the development, operation and control of the PWL Quality System to ensure compliance with ISO/IEC17025. The team liaises with HKAS on matters relating to accreditation and carries out audits of the PWL and contract laboratories. It also collaborates with HKAS on organising proficiency tests. Currently, about 210 of the PWL tests are HKAS accredited. In line with the CEDD’s policy to incorporate quality and environmental considerations in all aspects of the departmental projects and operations, the PWL also obtained accreditation of the environmental management system to ISO 14001 in 2007. Quality Management in the PWL

A collection of quality system documents is maintained in the PWL including Laboratory Quality Manuals, Laboratory Procedures Manuals and Technical Procedures Manuals, all of which are in electronic format.

Technical Development

Apart from providing quality services on construction materials testing, PWL also seek to develop new materials tests and testing techniques and to set out new or improved testing standards to meet industry needs. Below are some pertinent development work carried out by PWL in recent years with in-house capability or jointly with the industry, covering the geotechnology and technology of other construction materials:

  • Preparation of Geospec 3 “Model Specification for Soil Testing”
  • Publication of Construction Standard CS1:2010 “Testing concrete” , updating of Construction Standard CS2:1995 to CS2:2012 “Carbon Steel Bars for the Reinforcement of Concrete” and publication of Construction Standard CS3:2012 “Aggregates for Concrete”
  • Development of pull-out tests for horizontal reinforcing elements used in reinforced fill structures and slopes in accordance with Geoguide 6 “Guide to Reinforced Fill Structure and Slope Design”
  • Study on the durability and strength development of ground granulated blastfurnace slag (GGBS) concrete (GEO Report No. 258)
  • Alkali-aggregate reaction potential of volcanic rocks from Anderson Road Quarries & review on prevention of alkali-aggregate reaction in concrete (GEO Report Nos. 49 & 247)
  • Study of rapid determination of soil moisture content using the microwave oven drying and infrared oven drying methods (GEO Report No. 221 and GEO Report No. 301)
  • Study of the performance of soil suction and soil moisture measurement sensors for landslide assessment (GEO Technical Note No. TN 2/2011)
  • Study on the strength development of high PFA content concrete (GEO Report No. 48)
  • Development of ultra-accelerated mortar bar test for the determination of alkali-silica reaction potential in accordance with CS1:2010
  • Development of rapid chloride penetration test in accordance with CS1:2010
  • Development of testing for reinforcement connectors in accordance with AC133
  • Development of testing for measurement of surface geometry of reinforcing steel to CS2:2012
  • Development of testing for determination of chemical composition of reinforcing steel to CS2:2012
  • Study on the technical feasibility of using glass cullet as an engineering fill in reclamation and earthworks (GEO Technical Note No. TN 6/2014).
Technical Development
Technical Development

Information Sharing

For reference and use by all Government Departments and the engineering profession, the PWL are responsible for maintaining and updating the Steel Bar Circular Download PDF which records all unique bar patterns as identification of steel bar as registered in Hong Kong. Any firms which want to register their steel bar patterns can refer to A guideline on application for registration of bar pattern of confirmed origin Download PDF .

The PWL also prepare the Cement Circular Download PDF which is issued on a bi-monthly basis. It also publishes commonly used cementitious materials in public work projects.

Apart from the above, the PWL have set up a database of concrete mixes to facilitate other departments to scrutinize the quality record of concrete mixes from which concrete cube test results for the past one year can be searched with an assigned unique mix ID. The following email address "pwcl_con@cedd.gov.hk" can be used for further details and enquiries.

Laboratory Information Management System

To further improve the quality of PWL’s testing services, the PWL have developed and implemented the "Laboratory Information Management System" (LIMS). This system is designed to provide a working platform for handling testing activities, as well as to serve as a tool to strengthen administrative and management control of PWL's operations. The LIMS comprises a number of modules covering the full range of activities from registration of customers, receipt of test requests, registration of samples, inputting of testing data, data analyses to production of testing certificates/reports for some 110 common tests. It also includes many managerial functions related to contract management, financial control, workload monitoring, productivity and efficiency evaluation, etc.

Contact Us

Should you require further information, please feel free to contact our Chief Technical Officers or Principal Technical Officers whose telephone numbers are listed below, for specific topics at Public Works Regional Laboratories. Standard Test Request Forms can be obtained from Public Forms/Geotechnical Service or upon request.

Public Works Central Laboratory
Contact Person : Chief Technical Officer / Central Laboratory
Address : Public Works Central Laboratory Building, 2B Cheung Yip Street, Kowloon Bay
Tel No. : 2305 1290
Fax No. : 2795 9611
E-Mail : pwcl_cto@cedd.gov.hk

Public Works Regional Laboratories
Contact Person : Chief Technical Officer / Regional Laboratories
Address : 2 Container Port Road South, Kwai Chung, N.T.
Tel No. : 2439 9282
Fax No. : 31450131
E-Mail : pwrl_cto@cedd.gov.hk

Public Works Regional Laboratory (Tsuen Wan)
Contact Person : Principal Technical Officer / Tsuen Wan
Address : 2 Container Port Road South, Kwai Chung, N.T.
Tel No. : 2439 9282
Fax No. : 3145 0131
E-mail : pwrl_tw@cedd.gov.hk

Public Works Regional Laboratory (North Lantau)
Contact Person : Principal Technical Officer / North Lantau
Address : J/O Hei Tung Street & Man Tung Road, Tung Chung, Lantau, N.T.
Tel No. : 2109 0657
Fax No. : 2109 1030
E-mail : pwrl_nl@cedd.gov.hk

Public Works Regional Laboratory (Kowloon)
Contact Person : Principal Technical Officer / Kowloon
Address :Lok Wah Street, Tsz Wan Shan, Kowloon
Tel No. : 2703 7332
Fax No. : 2623 2757
E-mail : pwrl_kl@cedd.gov.hk

Public Works Regional Laboratory (Tai Po)
Contact Person : Principal Technical Officer / Tai Po
Address : J/O Ting Kok Road and Nam Wan Road, Tai Po, N.T.
Tel No. : 2144 1777
Fax No. : 2680 4763
E-mail : pwrl_tp@cedd.gov.hk

Public Works Regional Laboratory (Tin Shui Wai)
Contact Person : Principal Technical Officer / Tin Shui Wai
Address : Tin Ying Road, Ha Tsuen, Yung Long, N.T.
Tel No. : 2447 1677
Fax No. : 2448 3672
E-mail : pwrl_tsw@cedd.gov.hk