The Seminar on Useful Tool for Building Inspection - Diagnostic Tests on Concrete was co-organized by the Hong Kong Council for Testing and Certification (HKCTC), Hong Kong Accreditation Service (HKAS), Buildings Department (BD) and Vocational Training Council (VTC) on 17 April 2013.
In the beginning, Ir. LEE Shing-see (Convener, Panel on Promoting Testing and Certification Services in Construction Materials Trade, HKCTC) gave an welcome remarks. He said there were about 10,000 building older than 30 years and need to be inspected. Concrete test, product certification and building inspection were needed.
Group photo
The first speaker was Mr. LI Kwok-leung (Senior Structural Engineer, Mandatory Building Inspection Division, Buildings Department) and his topic entitled “Mandatory Building Inspection Scheme: An Introduction”. Mr. Li briefed the purposes, legislation and registered person roles of Mandatory Building Inspection Scheme (MBIS) and Mandatory Window Inspection Scheme (MWIS).
Under the MBIS, owners of building aged 30 years or above required to appoint a Registered Inspector (RI) to carry out the prescribed inspection once every 10 years. An RI may be an Authorized Person (AP), Registered Structural Engineer (RSE) or registered building professionals possessing relevant work experience.
The inspection scope covered:
- External elements and other physical elements;
- Structural elements
- Fire safety elements;
- Drainage system; and
- Identification of unauthorized building works in the common parts and on the exterior of the building.
Under the WBIS, owners of building aged 10 years or above required to appoint a Qualified Person (QP) to carry out the prescribed inspection once every 5 years. A QP is an Authorized Person (AP), Registered Structural Engineer (RSE), Registered Inspector (RI), Registered General Building Contractor (RGBC) or relevant Registered Minor Works Contractor (RMWC).
The second speaker was Ir. Samson WONG (Senior Accreditation Officer, HKAS) and his presentation was “Building Diagnostic Tests as Assessments Tools”. His discussion mainly focused on reinforced concrete structure and sharing non-destructive test methods to support MBIS.
Mr. Wong mentioned common Building defects included Concrete Spalling, Reinforcement Corrosion, Concrete Crack, Concrete Honey Combing, etc. He said non-destructive test methods were to estimate concrete strength; to identify possible defects, to locate reinforcement and estimate their sizes, and to estimate corrosion activities. He also introduced HOKLAS Supplementary Criteria No. 19 entitled "Construction Material Test Category - Accreditation of Diagnostic Tests on Concrete".
Then Ir. Kenneth PAK (Senior Project Officer, Engineering Discipline In-service Training Office, Vocational Training Council (VTC)) introduced building diagnostic Tests on Concrete.
Non-destructive test methods for building diagnostic tests on concrete were discussed.
- Carbonation test for carbonation depth
- Covermeter survey for concrete cover
- Half-cell potential measurement for rebar corrosion
- Infrared thermography for debond on external wall
- Resistivity measurement for corrosion risk of reinforced concrete
- Surface hardness measurement for concrete strength
- Surface penetration radar survey for rebar layout and concrete cover
-Ultrasonic pulse velocity measurement for concrete strength
The Third speaker was Ms. Bella Ho (Senior Accreditation Officer, HKAS) and his presentation named “Why Does the Use of Accredited Services Give Extra Confidence in Quality Assurance?”. Firstly, Bella introduced the history of HKAS and their service scope. Then Bella mentioned HOKLAS-accredited test activities for MBIS where Infrared Thermography and Surface Penetration Radar Survey were new accredited tests.
She also briefed the performance requirements for aluminum window specified for Dimensional Tests, Operation & Strength Tests, Tests on Coating, Weather-tightness Test and Tensile Test.
Proficiency Testing Programme was important in HOKLAS accreditation. Bella introduced the recent program covered Covermeter survey and Half-cell potential measurement.
The last session was led by Ir. Kenneth PAK (Senior Project Officer), Mr. John CHAN Chi-chui (Teaching Associate) and Mr. CHEUNG Ying-kit (Technician, Department of Construction, Hong Kong Institute of Vocational Education (Tsing Yi), VTC) and their topic named “Testing Equipment in Building Diagnosis: A Demonstration”.
The demonstration instrumentation and tests were covered HOKLAS accredited Test for Construction Materials (especially Non-destructive testing/Diagnostic tests).
The Q&A session
One of participants raised that the major problem was water leakage, which caused concrete corrosion and affected the strength.
Reference:HKCTC -
http://www.hkctc.gov.hk/en/about.htmlHKAS -
http://www.itc.gov.hk/en/quality/hkas/about.htmBuildings Department -
http://www.bd.gov.hk/english/index.htmlVTC -
http://www.vtc.edu.hk/html/en/about/corp_info.html
