MasterRoc HCA 20

MasterRoc HCA 20 is a high quality, liquid, non chloride chemical admixture which controls the dynamics of cement hydration with no loss of quality in the hardened sprayed concrete or in backfilling mortars, for TBM tunnels.The first component, MasterRoc HCA 20, dispensed into wet or dry mixes at the batching plant, is a liquid additive with a recommended dosage between 0,3 — 2% by weight of cement. It fully stabilizes the hydration process by forming a protective barrier around the cement particles.

The hydration process is suspended till the time set according to the dosage, or it is possible to immediately re-activate the hydration process adding a MasterRoc SA accelerator that breaks the barriera round the cement particles.

The second component, Accelerator (MasterRoc SA 193, MasterRoc SA 165, MasterRoc SA 142 o MasterRoc SA 411), is an activator that in case of sprayed concrete gives an instant bonding to the support, through a faster setting time (MasterRoc SA 193, MasterRoc SA 165, MasterRoc
SA 142 at 5-8%, MasterRoc SA 411 at 10-12%). In case of mortars or backfilling grouts it gives a modular curing (according to dosage variation in %). The system MasterRoc HCA is compatibile with all cements according to UNI EN 197-1.