Coupling of chemical kinetics and thermodynamics for simulations of leaching of cement paste in ammonium nitrate solution

Journal Article · Mon May 15 04:00:00 EDT 2017 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2017.02.028· OSTI ID:22697104

Yu, Yuguo

A novel numerical method is proposed in this paper to model the leaching of various types of cement pastes in the ammonium nitrate solution by coupling chemical kinetics with chemical thermodynamics. Arrhenius equation and Eyring equation are applied to predict the rate constant of fast dissolution of portlandite in the ammonium nitrate, and a modified rate law is developed by incorporating the saturation ratio of the reaction. The estimations of leached depths from the proposed method comply with the well-known square root-time relationship and they also agree well with the reported experimental results. Moreover, the evolutions of porosity and major hydrate compositions during leaching are obtained. It is found that a simple linear relation exists for the acceleration factor of leaching in 6 M of ammonium nitrate with respect to leaching in pure water regardless of the type of the cement clinker. - Highlights: • Chemical kinetics and thermodynamics are coupled to simulate the accelerated leaching. • The proposed method generates good estimations for leached depths and changes of porosity. • The proposed method can predict the detailed distributions of all the major cement hydrates. • A simple linear relation exists for predicting the widely scattered acceleration factors.

• OSTI ID: 22697104
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 95; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AMMONIUM NITRATES
ARRHENIUS EQUATION
CEMENTS
COUPLING
DEPTH
LEACHATES
LEACHING
MATHEMATICAL SOLUTIONS
REACTION KINETICS
SIMULATION
THERMODYNAMICS
WATER