Introduction

The idea of using chemicals to improve and harden soil has been known for a few thousand years. Lime mortar mixed with sand and clay were discovered on the floors of houses at the archaeological site of Lepenski Vir in Serbia, dating back to 7500 BC ( Radić et al. 2008 ). Lime was also used in the construction of the pyramids at Shersi in Tibet ( Miller 2000 ), as well as in Egypt, China, Greece, Rome and other ancient civilisations. In many of these construction-related applications, lime was commonly used in the admixture with soil in order to bring about pozzolanic reactions, which led to the production of cementitious products, that comprise mainly calcium silicate hydrate and calcium aluminate hydrate.