Pressure induced by salt crystallization in building materials-experimental and numerical analysis

Author(s): M. Koniorczyk, D. Gawin, P. Konca
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 987 - 996
Total Pages: 9
Language: English

MIP tests of the cement mortar saturated with NaCl, Ca2Cl, Na2SO4 solutions were performed. The changes of porosity, pore size distribution and pore shape were investigated by two intrusion-extrusion cycles. The crystallization pressure bursts the meso-pores. The model of coupled heat, moisture and salt transport considering the salt crystallization is presented. During salt crystallization an additional heat is released, which must be considered in the energy conservation equation of multiphase domain. The key factor while modeling the salt crystallization is the kinetics of salt phase change, which is approximated in the presented research by means of Freundlich non-equilibrium isotherms. In order to calculate the solution supersaturation ratio the short and long range ions interaction was taken into account applying the Pitzer model. The mathematical model was solved using FEM and FDM and some numerical examples were calculated and discussed. It was proved that the higher rate order is assumed in the kinetic law the higher crystallization pressure is obtained from simulations.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00