|Modeling the degradation of Portland cement pastes by biogenic organic acids|
Vol. 99 No. 5Novembre 18th, 2011
Modeling the degradation of Portland cement pastes by biogenic organic acids
A bioleaching test of OPC pastes by the fungus Aspergillus niger is modeled with the reactive transport code HYTEC. Modeling indicates that the biogenic organic acids (mostly carboxylic acids) strongly accelerate hydrate dissolution by acidic hydrolysis while their complexations of aluminum have an effect on the secondary gel stability only. Degradation depth could be affected by precipitation of calcium salts. Precipitation of calcium oxalate is predicted by modeling but was hindered in the present experiment.