OPTIMIX NS688 Expanding Grout Admixture is a powder additive for cementitious based mixes to provide positive expansion. OPTIMIX NS688 is added to the cementitious materials during the mixing process and they quickly reacts to produce a non-shrink material. OPTIMIX NS688 can be used in most grouting applications where a positive expansion is required. Typical applications include post tensioning duct grouting, void infilling, base plate grouting, sonic tube grouting in pile foundations, socket “H” pile and mini piling applications as well as soil nails grouting for slope stabilization.