Influence of the geopolymer formulation on the endogeneous shrinkage

The shrinkage of geopolymer materials is an important parameter to control for several applications. In this topic, study aims investigate the role used precursors (metakaolin and alkaline solution) different additives (sand, normalized sand, wollastonite, glass fibers) on shrinkage. For this, samples were synthesized stored at 20 °C 100% RH. Then, measurements carried out consolidation times. results have shown that measured endogenous because it not accompanied by mass variation only due self-desiccation. It was also evidenced solution controls fact, increase alkalinity or use sodium instead potassium solutions permits decrease values less than 400 µm/m 28 days. This result explained depolymerization degrees inducing geopolymerization rates kinetics affecting pore distribution size. metakaolin seems a lower impact effect studied. All reduce with extents in following order: sand > fiber wollastonite. has highest reduction (about 142 7 days) which can be modification granular skeleton porosity. A correlation proven show liquid solid ratio.