Use of iterative algorithms to calculate the softening curve in concrete

This paper presents an original procedure to determine the softening curve in concrete from a diametric Brazilian test and a three point bend test. An inverse procedure is proposed combining experimental results, numerical finite element computation and an iterative algorithm, called algorithm AMS-UPM, developed expressly for this research. The starting point of the algorithm is a bilinear softening curve, on which a successive transformations are applied decreasing the difference between the experimental and numerical results in each step. The procedure has been applied successfully to two conventional concretes. The final result is a softening curve that adjusts almost perfectly experimental data of the three point bending test. (C) 2018 SECV. Published by Elsevier Espana, S.L.U.