Review article

Plane sections hypothesis is formulated for average strain values on crack spacing within the deformation model theory. Local rebar strain in cracked sections can considerably differ from an “average” one. Range of values of rebar local strains is achieved under an alternative hypothesis. According to the hypothesis, linear strain distribution is assumed for compressed concrete, but rebar strain is an independent unknown. Within research of flexural members, the deviation of local rebar strain in crack from its average value on a crack spacing is in a range from -16.6% to +5.1%. Deviation range for singly reinforced cross-sections at μ = 1.0…2.0% is comparable with the limits of engineering error and it is from -5.0% to +2.5%.