how can we simulate the cycle of tidal

Hi everybody,
i have the model of concrete cube Cm x 16 Cm, i have to simulate this model with condition of the tidal, that s mean :
6 h humidification and 6 h drying so the results of the fist step is the condition of the second step, i cans use "store solution " for small number cycle (10 or 15) but i have to simulate with 1000 days (2000 cycles) for example. So anybody help me how to resolve this model ?
Thanks
Regard
TRAN Van Quan
Ecole centrale de Nantes
Nantes-France