Cement Matrix Modified by Mesoporous Silica of the MCM-41 Structure Type: Early-Age Properties and Microstructure Evolution

This paper describes the results of a study on the influence of mesoporous silica of the Mobil composition of matter No. 41 (MCM-41) structure type on the early-age properties of the cement matrix (CM) and the microstructure development. To date, no studies related to the use of MCM-41 to modify the CM structure have been reported in the literature. The MCM-41 used in this study was produced from a waste material created during the conversion process of fly ash into synthetic zeolites. A number of physicomechanical, and compositional properties were tested. MCM-41 was applied in amounts of 0.25%–2% by weight of cement in a manner that allowed its uniform dispersion, and tests were performed as a function of maturation time, i.e., after 1, 3, 7, 14, and 28 days. The MCM-41 was found to accelerate the cement hydration process and its use promotes the formation of a more compact, gel-like CSH phase with greater cohesion.