Abstract:
Cracking in reinforced concrete structures affects the serviceability and durability of structural
members. These effects are mostly occurred due to excessive size of crack width on the sides of
RC members. As the crack width increases on the surface of flexural/tensile loading members,
corrosion occurrence is probable to the embedded steel reinforcement. To overcome such
problems, different standard codes provide analytical expressions to limit the size of crack
width. Thus, to have safe and durable structures, comparing the expressions of crack width
limits in different standard codes is important to get best practices among the codes.
In this study, the analytical crack width expressions of American, British, and Ethiopian
Standard codes were considered. The analytical crack spacing of Ethiopian standard code and
Model code (MC2010) were also compared. The study is made through calculation of crack
width and crack spacing in the respective codes, comparing it with experimental results in
previous studies and Finite Element Numerical modelling in Abaqus. In the comparison, the
effects of parameters such as concrete cover, bar diameter, and loading types were discussed.
Firstly, the analytical results of each code crack width limit expression were compared with
the experimental crack width results. As a result, while considering the estimation of crack
width in different codes, it could be observed that the ACI code gave a relatively good fit to the
experimental crack widths than ES-2 and BS codes. On the other hand, for the estimation of
crack spacing, the value estimated by MC-2010 gives relatively closer results to the
experimental crack spacing than ES-2.
Secondly, to code’s crack width and spacing analytical comparisons, the 3D nonlinear finite
element model, Abaqus, was used to predict the cracking behaviour of reinforced concrete
tensile loading beam. Accordingly, the simulation crack patterns result indicates a good fit to
that of the experimental crack patterns result.
In conclusion, when considering the cases of all codes, and based on the percentages of
variations, it is observed that the existing codes need to improve the expressions for crack
width calculation.
