Using Crackamite: Mixing

Crackamite is a powder that must be thoroughly mixed with clean water before use, in a ratio of 30 % of the overall weight (1.5 litres for each 5 kg package). Gradually add the powder to water, stirring all the time to obtain a smooth, lump-free mortar.

Mixing Equipment

Mix Crackamite with water, one bag at a time, by hand or, preferably, with a mechanical mixer. Prepare the following equipment:

  1. Container: A metal or plastic bucket or clean can of 10 - 20 litres capacity.
  2. Mixer: Preferably a handheld mechanical mixer.
  3. Water Measurement: Fixed volume bottle, beaker or measuring cylinder.
  4. Protection: Rubber gloves and boots, and safety glasses.

Mixing Method

Pour approximately 1.5 litre (0.4 U.S. gallon) of water into container. Add one bag of Crackamite gradually and mix well until it has a good fluidity.

When viscosity of the mixture of Crackamite and water is too high to pour into the hole, add a little water to get a good fluidity. Do not exceed 34% of water ratio (1.7 litre; 0.45 U.S. gallon per 5 kg; 11 lb. of Crackamite). The mixing time by hand-mixer is about 2 - 3 minutes. It is recommended that a mechanical mixer be used on large volume jobs. When mixing by hands, wear rubber gloves.

Mixing Water

  1. Use clean water that is not contaminated with oil, organic substances, etc.
  2. Use the proper temperature of water for each grade of Crackamite
  3. Water at a temperature below 15°C (59°F) must be used when the average atmospheric temperature is more than 45°C for Crackamite CM - H.
  4. The cooler the water is, the longer Crackamite mixture will remain fluid.

Standard Quantity

The quantity of Crackamite to be used for cracking differs with the hole spaces and diameters. In the table below, the relation between the quantity of Crackamite used and the hole diameters is indicated for the hole of 1 m depth, where Crackamite is mixed at a water ratio of 30%.

Kg/m values for different hole sizes
Hole Diameter 30 mm 32 mm 34 mm 36 mm 38 mm 40 mm 42 mm 44 mm 46 mm 48 mm 50 mm
Crackamite (Kg/m³) 1.2 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.8 3.0 3.2
Hole Depth One Meter
Note: You may get 3% to 6% less yield due to field conditions.

Audit Checklist Before Mixing

  1. Are people on the work site wearing safety equipment?
  2. What is the rock/concrete temperature?
  3. What is the water temperature?
  4. What is the drill hole diameter?
  5. Have you calculated the extra water required if rock/concrete temperature is above 22°C?
  6. Are you going to cover the filled holes with a tarpaulin sheet?
  7. How much time does it take to fill the hole?
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