Crack width variation within the concrete cover of reinforced concrete members

Crack width in reinforced concrete structures is usually considered to be constant within the concrete cover by design codes. This simplification can lead to inaccurate or uneconomical design and it is completely misleading for a possible crack repair design. Aim of present experimental studies is to investigate the application possibilities of PU injection resins for active cracks in dynamically loaded structural concrete members. Present paper summarizes the results of the preliminary studies carried out with epoxy injection resin for a detailed survey of the variation of crack widths within the concrete cover of reinforced concrete tensile members. The paper highlights the significance of different concrete covers on the variation both of internal and surface crack widths, confirms several findings of previous studies including the influence of the so-called Goto cracks, and appreciates the recently developed proposal of the fib Model Code 2010 concerning the variation of the crack width along the concrete cover in the form of a power function.