Upon filling of the pre-drilled holes with the mixed Crackamite slurry, reaction immediately starts to occur in the Crackamite. Upon reacting, the Crackamite mortar starts hardening and expanding causing the material to develop cracks. The cracks generally appear within 3 to 20 hours after filling, depending on the temperature. These cracks spread further and become wider with time.
Reaction starts as soon as Crackamite is mixed with water causing it to expand and harden. When the Crackamite expansive mortar is packed into a hole in stone or concrete, it swells and exerts pressure on the hole-walls and thus fractures it.
The cracks appear within 45 minutes after filling, depending on weather, rock or concrete temperature. The cracks become wider with time. The ambient temperature in the material being cracked determines the reaction speed. The higher the temperature, the shorter the reaction time.
The time required for full crack formation in material at 30°C is about 6 - 8 hours. The lower the temperature, the longer the crack formation takes. The crack width for rock continues to increase with time and can become 10 - 30 mm (3/8" - 1 1/8") after several days, depending on free surface available. It is best to wait until Crackamite has worked to full depth before removing the rock, as premature removal at the first sign of a crack can hamper the leverage effect of Crackamite.
Some points to remember after filling, while waiting for the cracks to appear:
For Crackamite, the higher the temperature, the quicker is the reaction. There are two ways to control the cracking agent's reaction time. For universal type, reaction inhibitors of 20 gram per bag are available for each 5 kg package in carton. 20 gm inhibitor can be added into water first and then the powder can be mixed to avoid the possibility of blow out shots. For quantity details refer to the following table:
| Site Temperature | Qty of Bag (20 g) |
|---|---|
| 5 °C | None |
| 15 °C | 1 per 3 bag |
| 25 °C | 2 per 3 bag |
| 35 °C | 1 per bag |
When the cracking gap is around 3 - 5 cm, you can carry out the further demolition work. After cracks initiate, secondary breaking is carried out with a hand-breaker, a pick-hammer, a giant hydraulic breaker, a ripper, etc. It is best to wait until the Crackamite has worked to full depth before removing rock or concrete since premature removal at the first sign of a crack hampers the leverage effect of Crackamite.
| Type of breaking by Crackamite | Secondary breaking required |
|---|---|
| Fragmentation | Hammer, Power shovel |
| Crack Formation | Hand breaker, Power shovel, Hydraulic breaker |
| Pre-splitting | Combination of mechanical breaker or dynamite |