Oligomerization of Silicate Anions in Portland Cement Hydration

Abstract

According to the classic theory of cement hardening, the strength of hardened cement is carried by non-chemical bonds. In this paper the importance of chemical bond formation during cement hardening is emphasized. In this process corner sharing (bridging) common oxygen ions serve as a bond between adjacent SiO4-tertrahedra. from this point, cement hardening resembles the hardening of plastics; both processes can be describes as polymerization reactions with the difference that -C-C-C-C- and -Si-O-Si-O-Si- chins (or rings, and sheets etc.) are formed in the latter and former case, respectively. However, as the degree of polymerization in cement is low in contrast to plastics, the term "oligomerization" is suggested. The possible confirmation of the proposed theory and some practical results are outlined.