2013 Articles

Novel Evidence for the Formation of Semi-Permeable Membrane Surrounding the Portland Cement Particles During the Induction Period

Hou, Pengkun; Kong, Deyu; Kawashima, Shiho; Qian, Jueshi; Corr, David J.; Shah, Surendra P.

This letter presents strong novel evidence for the semi-permeable membrane surrounding Portland cement during the induction period. In the cement hydration, heat curve obtained through high-resolution differential scanning calorimetry under isothermal conditions, one main and some other smaller endothermic peaks were detected. These endothermic peaks are believed to be caused by the osmotic expansion that occurs after the semi-permeable membrane forms, not the precipitation of calcium hydroxide or the imbibition of water during the induction period.