{'fraction_non_alphanumeric': 0.026143790849673203, 'fraction_numerical': 0.006535947712418301, 'mean_word_length': 5.20945945945946, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Qualitative model of concrete acidification due to cathodic protection

In this paper a mathematical description and numerical implementation for ion transport in concrete due to current passage is developed, in which the heterogeneous equilibrium between Ca2+, OH− and the solid Ca(OH)2 is incorporated. The description is based on the Nernst–Planck equation for ion transport, and reaction terms for the dissolution/precipitation of Ca(OH)2. This description was implemented in the finite element package Comsol Multiphysics. In this way Ca(OH)2 depletion in a zone at a CP anode adjacent to a bulk of concrete with Ca(OH)2 could be modelled in one calculation. Drawback of this model is that the kinetic parameters in the reaction terms are not known, and must be chosen high to ensure the dissolution of Ca(OH)2 to be in equilibrium. This proved numerically challenging and sometimes caused long calculation times.