The benefits of incorporating glycerol carbonate into an innovative pozzolanic matrix

A green admixture, glycerol carbonate (GC), has been incorporated into an alternative binder composed of hydraulic lime and metakaolin. The new properties achieved are rapid hardening, an improvement of compressive strength and a reduction in shrinkage. A study of the rheological behaviour and monitoring of conductivity, pH and organic compounds concentrations in diluted solutions led to the conclusion of an early precipitation of calcium carbonate due to GC decomposition. This phenomenon is believed to be responsible for the early stiffening of the paste. XRD and TG analyses showed changes in the mineralogical hydrated phases formed in the presence of GC: calcium aluminium oxide hemi-carbonate hydroxide hydrate is the only aluminate phase existing in this mineralogical system and more C–S–H are formed. These differences could explain the enhancement in the paste mechanical performance. The study concludes that this innovative pozzolanic matrix has considerable potential as a binder in building ecocomposites.