We have a new publication by CCR. It is related to why the shrinkage of concrete containing fly ash is smaller than that of OPC.　Ca2+ ion in the interlayer space of C-A-S-H has two roles:
1) Less number of Ca2+ ions in interlayer space reduces the attractive force between C-S-H sheets and produces larger interlayer space during drying
2) Resultant less stacking of sheets after drying (less irreversible microstructure change and less change in surface area.)
The Ca/Si ratio of C-A-S-H has a very important role in drying!

M. Segawa, R. Kurihara, A. Aili, G. Igarashi, I. Maruyama, Shrinkage reduction mechanism of low Ca/Si ratio C-A-S-H in cement pastes containing fly ash, Cem. Concr. Res. 186 (2024) 107683. https://doi.org/10.1016/j.cemconres.2024.107683.