Stabilisation of Poured Earth with Geopolymers

Abstract

This study investigated the possibility of modifying the effect of water-induced porosity on the strength of the geopolymer binder by modifying the synthesis steps. Starting from an optimal water content, which shows the highest early strength according to the general manufacturing process, geopolymers with different amount of water-induced porosity are produced by adding further water to the geopolymer paste after a certain rest period. At very high water contents, a residual strength of the geopolymer mortar samples of about 1.5 𝑀𝑃𝑎 could still be achieved with this two-step method, where tests could no longer be carried out with the general one-step method. In addition, Vicat tests show an earlier setting of the geopolymer mortar samples manufactured with the two-step method above a porosity of 𝜑 = 0,60.