Speaker
Description
The degradation of concrete due to acid attack is commonly assessed by the depth of deterioration from the original surface. This study evaluates the applicability of a simple diffusion-based model to determine the apparent diffusion coefficient (D_app), comparing it to an empirically modified square-root-of-time approach from the fib Model Code 2020. Model calibration was based on accelerated laboratory experiments in which calcium aluminate cement (CAC) mortar specimens were immersed in 1.0 M or 0.10 M acetic acid solutions for two consecutive 22-day periods, with solution replenishment between phases. Degradation was monitored through pH changes, mass loss, and microstructural/chemical deterioration depth analyses. Elemental concentration profiles, obtained via electron probe microanalysis (EPMA) and processed through a newly developed image analysis algorithm, quantified decalcification and dealumination across the degradation front. These data enabled calibration of model parameters, supporting a robust comparison of modeling approaches for predicting acid-induced CAC mortar degradation.
Affiliations
Institute of Construction and Building Materials, TU Darmstadt, Franziska Braun-Straße 3, 64 287 Darmstadt, Germany, ukrainczyk@wib.tu-darmstadt.de
| Keywords | Calcium Aluminate cement, Acetic Acid Degradation, Image analysis, Mathematical Modelling, Durability. |
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