Shrinkage influence on tension stiffening in concrete members

Most known tension stiffening relationships have been derived using test data of shrunk reinforced concrete members. Therefore, tension stiffening was coupled with shrinkage effect. The paper discusses the influence of shrinkage and accompanying creep on tension stiffening of tension and bending concrete members subjected to short-term loading. Based on numerical experiments, a simple transformation formula has been proposed for eliminating shrinkage from tension stiffening relationships of tension and symmetrically reinforced bending members. For asymmetrically reinforced members, a more sophisticated procedure based on the earlier proposed inverse technique has been applied. Using experimental moment–curvature diagrams, the tension stiffening relationships were iteratively calculated for the extreme tensile concrete fibre. The shrinkage effect was eliminated by assuming a reverse shrinkage strain. Based on the proposed techniques, free-of-shrinkage tension stiffening relationships were derived from shrunk tension and bending RC members reported in the literature.