Description

This project will employ a combination of time resolved and high resolution X-ray diffraction to analyse the effect of novel sol-gel silicates as seeding agents on the hydration kinetics of Portland Cement (PC). We aim to quantify the consumption of PC clinker minerals and the formation and evolution of various crystalline reaction products (such as …) with the in-situ addition sol-gel silicates. Calcium silicate hydrate gel (C-S-H) is the principal product of PC hydration, responsible for strength, permeability and shrinkage. Our work focuses on the novel use of sol-gel silicates as seeding agents in-situ, to tailor the nanostructural properties of C-S-H and to promote the nucleation and self-assembly of hybrid C-S-H nano-building units, for superior mechanical performance and resilience. Our findings show that the parameters for the sol-gel synthesis can be used as a pathway to tune the early age PC hydration kinetics (Fig. 1a & b) and to facilitate the formation of C-S-H with unique morphologies (Fig. 1c & d). We intend to employ X-ray diffraction to analyse the consumption of the PC clinker minerals and the formation and evolution of various crystalline reaction products thereby quantifying the effect of sol-gel silicate addition on kinetics. Information regarding the activities during the pre-nucleation and nucleation stages of C-S-H in the inorganic and organic sol-gel-SiO2-CaO-H2O system will allow us to optimise the synthesis parameters to facilitate ‘programmable’ microstructural characteristics and to functionalise the properties of C-S-H for specific end uses.

Key findings

Results expected
The SRXRD data will allow us to map out for the first time the evolution of the mineral phases during the hydration reactions following the addition of sol-gel silicates. Through cross correlation with calorimetry and in-situ FTIR we will be able to optimise our synthesis parameters to gain enhanced control over the kinetics, the microstructural characteristics, and to promote functionalised properties of C-S-H in PC systems. Our data has already shown great promise in this area of research and we intend to pursue this with future grant applications. Our focus is to produce a cementitious matrix with improved stability that is less prone to degradation mechanisms. Such enhancements would allow the reduction of PC in any given mixture of concrete without compromising on performance and durability characteristics. In this manner brining us closer to producing novel, smart and low-carbon concretes.
Short title9 shiifts
AcronymTime-resolved Synchrontron XRD: Cement - solgel kinectis
StatusNot started