Grout Pumping and Injection Operations TR 003 properties of the grout. So the mixing must be completed correctly to ensure that the intended properties of the grout are achieved. The grout materials used on this project are generally as follows: ▪ Portland cement – Type HE (High Early Strength), the base material of the grout. Type HE cement is finer than GP (General Purpose) cement and has advantages of improved penetration, faster setting and higher early strength. ▪ Microfine Cement – This type of cement may also be used where greater penetration of the rock strata is required. This product has its own specific batch card (batching process remains the same). ▪ Groutaid ®- an additive, used to improve the overall properties of the grout including stability, flow, penetration and strength. ▪ SP-40®- a superplasticising additive, used to aid the dispersion of cement particles, i.e. separate them, to maximise flow of the grout for a given water content. This enables the production of fluid grouts over a wide range of water/cement ratio. ▪ “Blocker” grout (in two parts Cmax™ & Thermax™) is a controlled-set, 2-part, mineral cement used as a blocker or quick setting agent. ▪ The combinations of materials are designed to give the grouts the properties of “highperformance” injection grouts, i.e. ▪ < 2% bleed (doesn’t settle, water doesn’t separate from the grout) ▪ < 2% volume loss from liquid state to hardened state (minimal shrinkage) ▪ Very stable under high grouting pressure (no pressure filtration). ▪ Very good flow & penetration into rock structure (low viscosity). All mixes are carefully proportioned and each mix and the component materials are detailed in grout mix batch cards.
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