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, Sham Shui Kok, Tin Shui Wai and North Lantau. The PWL together have around 240 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), Ground Granulated Blast Furnace Slag (GGBS), 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 588,000 tests on various construction materials were carried out in 2020.

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 some 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. In some circumstances that the requested services are not readily offered by local commercial laboratories and resources are available in PWL, 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 to operate manually or automatically, with all the data captured directly into a computer. The PWL are capable of testing up to 18 soil specimens simultaneously.

In addition to providing the above traditional testing services, the PWL continue to proactively explore, research into and develop new tests in order to meet the needs of the construction industry in Hong Kong. Recent examples include using infrared heating technology for rapid soil moisture content determination and testing unconfined compressive strength of cement stabilised soil.

Use of Infrared Oven for Rapid Soil Moisture Content Determination - PWL have developed the use of infrared heating technology to dry soils. This technological advancement reduces significantly the time required for drying and the moisture content can be determined within about 3.5 hours comparing with at least 20 hours when conventional oven is used. This helps to speed up the progress of filling works on site.

Unconfined Compressive Strength Test on Cement Stabilised Soil Cores

Unconfined Compressive Strength Test on Cement Stabilised Soil Cores - Deep cement mixing has become widely used in reclamation works. Through this test, unconfined compressive strength of cement stabilised soil cores can be measured for verifying the quality of deep cement mixing works.

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.

Construction Materials Testing

The PWL perform compliance testing of construction materials, such as aggregates, bituminous materials, concrete, cement, PFA, GGBS, 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.

Universal Testing Machines with different capacities

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.

Automatic concrete compression machines

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.

Chemical Testing

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

The services cover a wide range of areas, including routine chemical compliance testing of aggregates, cement, hardened concrete, soil, pulverised-fuel ash, steel reinforcing bars and granulated blastfurnace slag; and examination of miscellaneous samples for forensic investigation by Government Departments.

Chemical Testing

Introduction of new construction materials over the years has necessitated the installation of a number of new equipment in the PWL, which include atomic absorption spectrometer, spark optical emission spectrometer, nitrogen analyser and carbon sulphur analyser.

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. In addition to in-situ testing services, 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 subject to the resource availability. 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. Most of the calibration services are accredited by HKAS.

Outsourcing and Specialist Lists Management

In order to provide efficient testing services, 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.

Quality Management

PWL Quality Management System

The PWL are operated under a Quality Management System by a team of professional and technical staff. The team is responsible for managing and supervising the development, implementation and control of the PWL Quality System to ensure compliance with ISO/IEC17025:2017. The team liaises with HKAS on matters relating to accreditation and carries out audits of the PWL and contract laboratories. Currently, about 190 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.

A collection of quality system documents is maintained in the PWL including Laboratory Quality Manual, Laboratory Procedures Manuals and Technical Procedures Manuals.

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 the need of the industry. Examples of development works 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 are given below:

Information Sharing

For reference and use by the Works Departments, 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. Steel bar suppliers interested in applying for listing their steel bar patterns in the circular can refer to the Guideline on Application for Registration of Bar Pattern of Confirmed Origin Download PDF .

The PWL prepare and issue the Cement Circular Download PDF on a bi-monthly basis. They also publish commonly used cementitious materials in public works 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 "" 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 (see contact details below). Standard Test Request Forms can be obtained from Public Forms/Geotechnical Services 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 :

Public Works Regional Laboratories

Contact Person : Chief Technical Officer / Regional Laboratories
Address : No. 550, Cheung Tung Road, Siu Ho Wan, Lantau Island, New Territories
Tel No. : 2439 9282
Fax No. : 31450131
E-Mail :

Public Works Regional Laboratory (Sham Shui Kok)

Contact Person : Principal Technical Officer / Sham Shui Kok
Address : No. 550, Cheung Tung Road, Siu Ho Wan, Lantau Island, New Territories
Tel No. : 2439 9282
Fax No. : 3145 0131
E-mail :

Public Works Regional Laboratory (North Lantau)

Contact Person : Principal Technical Officer / North Lantau
Address : No. 550, Cheung Tung Road, Siu Ho Wan, Lantau Island, New Territories
Tel No. : 2109 0657
Fax No. : 2109 1030
E-mail :

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 :

Public Works Regional Laboratory (Tai Po)

Contact Person : Principal Technical Officer / Tai Po
Address : J/O Ting Kok Rd & Nam Wan Rd., Tai Po, New Territories
Tel No. : 2144 1777
Fax No. : 2680 4763
E-mail :

Public Works Regional Laboratory (Tin Shui Wai)

Contact Person : Principal Technical Officer / Tin Shui Wai
Address : Tin Ying Road, Ha Tsuen, Yung Long, New Territories
Tel No. : 2447 1677
Fax No. : 2448 3672
E-mail :