Hong Kong Regulations

BUILDING (CONSTRUCTION) REGULATIONS - REGULATION 63

Core testing

Further testing

(1) When concrete is considered from visual inspection to be suspect or when
the specified grade strength has been deemed not to be attained under
regulation 59 the compressive strength of the concrete in the structure may be
determined by drilling a sufficient number of cores from the concrete at
suitable locations.

(2) The nominal minimum size of the core shall be 150 mm diameter for 40 mm
aggregate and 100 mm diameter for 20 mm aggregate or less, and the length of
the test sample cut from the core shall be at least 95% of the core diameter.

(3) Cores drilled from concrete shall be prepared and tested by a recognized
method to determine compressive strength.

(4) No adjustment shall be made to the measured strength in respect of the age
of the core when tested. (Enacted 1990)