Applicability of existing crack controlling criteria for structures with
large concrete cover thickness: Review.
Abstract
Adverse effects from the cracks in Reinforced Concrete (RC) structures
are controlled at the structural design stage. Cracks due to service
load are controlled by limiting the ‘calculated crack width’ to a
‘maximum allowable crack width’. With the understanding of social and
economic advantages of long design life structures, there is a trend of
constructing structures up to 300 years of design life. To enhance
durability, such structures require relatively large concrete cover
thickness. The existing ‘crack width calculation models’, have to be
validated before using on such large cover structures. The predictions
of crack width calculation models in Eurocode 2, Model Code 2010,
Japanese Code, American Code and British code were compared with the
results of recent experiments with large cover specimens. It could
identify that the aforementioned models have to be improved to predict
the crack widths of large cover structures. The necessary improvements
of each model have been identified. Next, a literature survey was
conducted to check the applicability of the existing ‘allowable crack
width limits’, for the structures with large concrete covers. To
effectively use the existing allowable limits on such structures, the
necessary improvements and future works have been identified considering
the durability, aesthetic and tightness criteria.