Chapter 8: Load and material factors for the full structural investigation

Full structural investigation of the existing concrete structure has to be carried out to determine the extent of the repair, strengthening and replacement necessary to restore its structural and service performance functions. This chapter will address the load and material factors required for the full structure investigation in accordance with the current codes of practice. Appraisal of existing concrete structures is performed in accordance with the latest codes of practice. It should be noted that BS EN 1991-1-1 (BSI, 2002b) specifies concrete strength class by both the cylinder strength and cube strength (for example C25/30 is a concrete with a characteristic cylinder strength of 25 MPa and cube strength of 30 MPa at 28 days). There may be a need to convert the in situ concrete cube strength to the corresponding cylinder strength or vice versa. The relationship between cube strength and cylinder strength will be discussed. Depending on the objectives of the full structural investigation, different types of safety factor will be defined.