The initial microscale mechanisms and materials interfacial process responsible for hydration of calcium silicates are poorly understood even in model systems. The lack of a measured microscale chemical signature has confounded understanding of growth mechanisms and kinetics for microreaction volumes. Here, we use Raman and optical spectroscopies to quantify hydration and environmental carbonat...

Time-dependent hydration process of Portland cement presents a complex system with several uncertainties. A presented four-parametric affinity hydration model captures well the hydration kinetics when three parameters are treated as fuzzy numbers. The equations for the fuzzy affinity hydration model are derived using Zadeh’s extension principle, which allows for simplifying calculations to obta...

In this study, the early age hydration kinetics of BOF slag is investigated. Isothermal calorimetry and in-situ X-ray diffraction (XRD) are used to examine effects K3-citrate concentration nanosilica addition on reactivity. The results reveal that brownmillerite most reactive phase during first 24 h hydration. controlled by dosage, reaction strongly accelerated with highly concentrated solution...

Proton transfer in protonated Nafion fuel cell membranes is studied using several pyrene derivative photoacids. Proton transfer in the center of the Nafion nanoscopic water channels is probed with the highly charged photoacid 8-hydroxypyrene-1,3,6-trisulfonate (HPTS). At high hydration levels, both the time-integrated fluorescence spectrum and the fluorescence kinetics of HPTS permit the determ...

The dynamics of water and its effect on proton transport kinetics in Nafion membranes are compared at several hydration levels. Nafion is the most widely used polyelectrolyte membrane in fuel cells. Ultrafast infrared spectroscopy of the O-D stretch of dilute HOD in H2O provides a probe of the local environment and hydrogen bond network dynamics of water confined in the hydrophilic regions of N...

The properties of confined water and diffusive proton-transfer kinetics in the nanoscopic water channels of Nafion fuel cell membranes at various hydration levels are compared to water in a series of well-characterized AOT reverse micelles with known water nanopool sizes using the photoacid pyranine as a molecular probe. The side chains of Nafion are terminated by sulfonate groups with sodium c...

The production of ordinary Portland cement (OPC) as the most expensive constituent of concrete is associated with destructive environmental effects and significant energy consumption. Thus, the use of supplementary cementitious materials such as Natural or synthetic pozzolans is a fundamental solution that affects the kinetics of hydration of cementitious materials. In this article, to evaluate...