Sodium silicate-based grouting material performance on various soil particle size fractions under acidic conditions

Sodium silicate is admitted as the first kind of chemical grouting material. It has been well know that its performance depends on the concentration of components which mixed in a grouting material. In this study, sodium silicate is reacted with weak acid salts reactant type combined with organic compounds reactant type to generate five types of grouting material. This project aims to find out a proper grouting material based on sodium silicate to be applied to dam construction purposes in Indonesia which mostly its dryland is covered by acid soil. The grouting material is tested on various soil particle size fraction which reflecting Indonesia soil particles such as poorly graded sand, well graded sand and clayey sand. This paper also presents physical properties of grouting material before this grouting material mixed with soil. It is found that gelling time of grouting material is influenced by concentration of sodium bicarbonate. Moreover, concentration of acetic formic anhydride is able to increase speed of bleeding. It is also found that injection of grouting material which consisted of sodium silicate, 4.34% w/w of reactant 2 which consist of 40-60% of sodium bicarbonate and 40-70% of potassium bicarbonate, and 0.89% w/w of reactant 3 which consist of 99% of acetic formic anhydride into well graded sand generate best grout-soil. However, the strength of this grout-soil decreases up to 50% when meet acid condition.