Equivalent model of expansion of cement mortar under sulphate erosion

Jue Zhu1 Minqiang Jiang2 Jiankang Chen1?
1(Mechanics and Materials Science Research Center, Ningbo University, Ningbo 315211, China)
2(State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics,
Chinese Academy of Sciences, Beijing 100080, China)

Received 24 June 2008

ABSTRACT The expansion property of cement mortar under the attack of sulfate ions is studied by experimental and theoretical methods. First, cement mortars are fabricated with the ratio of water to cement of 0.4, 0.6, and 0.8. Secondly, the expansion of specimen immerged in sulphate solution is measured at different times. Thirdly, a theoretical model of expansion of cement mortar under sulphate erosion is suggested by virtue of represent volume element method. In this model, the damage evolution due to the interaction between delayed ettringite and cement mortar is taken into account. Finally, the numerical calculation is performed. The numerical and experimental results indicate that the model perfectly describes the expansion of the cement mortar.