It is important to know how ROAR expansive cement works. Its basic principle is the high pressure it exerts on the material. That expansion pressure must be well directed. The expansion pressure will be directed to where you find less resistance. That is why it is very important to drill taking into account the free face of the rock since all the cement pressure will be oriented towards that place.


In case we are interested in making small pieces of rock so that it can be handled manually or with small machines.

In this case a square mesh is made. With a separation between holes of 8 to 10 times the diameter of perforation.

The approximate consumption of this method is between 10 Kg / m3-25Kg / m3 (depending on the hardness of the rock)


In this case it is interesting to break the maximum volume of stone with the minimum possible consumption.

In this case you want to make stones as large as possible and as long as it can be loaded by a machine. Lines parallel to the free face will be drilled. With a distance between holes within the same drilling line between 5 to 8 times drilling diameter and a separation between line 15 to 40 times the drilling diameter.

The approximate consumption of this method is between 1 Kg / m3 - 10 Kg / m3 (depending on the hardness of the rock)

In option A the distance K must be similar to the distance L

In option B the distance of K can be 2 to 80 times greater than the distance of L (Depending on the hardness of the stone)


If there is no free face, you have to do it. This is achieved by tilting the holes at angles between 60º to 45º. This ensures that the pressure of the ROAR expansive cement is directed upwards. In this case, the separation between the holes should be reduced by 30% to 50% in a normal drilling, increasing the consumption of this method between 15 to 35 Kg / m3. Whenever possible, small strips will be made to achieve a small free face and thus continue with the ordinary method.

It is also advisable to make vertical holes in the center of the V (Strain) to help the expansion. These may not be charged or partially charged.


Element to break Hole depth Distance between holes Linear distance between holes Hole diameter Kg / m3
Soft stone 100% 40-100 60-90 30-40 5-10
Middle stone 105% 30-40 60-90 38-42 12-22
Hard stone 105% 25-40 30-80 38-42 18-25
Mass concrete 80-85% 20-30 60-90 38-42 12-18
Reinforced concrete 90-95% 15-30 60-90 38-42 18-25


In some of the cases we have footings columns or types of structures that we want to ensure that they are not damaged. For this, an unfilled safety drill line can be made close to the structure. This creates a zone of discontinuity of the tensions produced by the Roar expansive cement (This line must not be filled) which serves as a strain.


  1. The maximum depth of a hole is 9 meters.
  2. The maximum advisable depth of a hole is 3 meters.
  3. The minimum depth of a hole is 4 times the diameter of that hole.
  4. In reinforced concrete, drill 90% to 95% of its depth. In cornices or projections, drill as deep as what you want to extract. In slabs, drill 2/3 to ¾ of the thickness of the stone.
  5. In soft stones, such as marble, the depth of the hole is 100%, in medium or hard stone, such as granite, the depth of the hole is 105%.
  6. The best working diameter is 38 mm.


  1. The holes must be drilled to allow a free face so that the ROAR EXPANSIVE CEMENT can push. For example, drilling at a 45º angle on a flat surface will push it up, but by drilling straight down, it may not allow any pressure outlet. To tear down a block without pushing out the walls, which surround, drill a cone-shaped design in the center and fill these holes first. The cone will burst up and create a free face.
  2. The design of the hole depends on the tensile strength of what is being broken, and the size of the pieces you want when it is being made. This can often be determined experimentally.
  3. The hole design also depends on how fast the results are needed. More holes in less distance will result in less breakage time and more small parts, but this means much more work and more ROAR EXPANSIVE CEMENT.
  4. Slabs are much easier to break than reinforced concrete or protrusions, and drills can be separated further, especially if the breaking speed is not essential.


To calculate the amount of ROAR expansive cement to be used. You need to know the number of holes, the depth of the holes. With these data calculate the linear meters that you are going to make and according to the drilling diameter you can calculate the following formula:

These are theoretical data of consumption of Kg per linear meter but it must be taken into account that there are factors that can influence the real consumption of ROAR expansive cement. Such as the wear of the drilling materials, the cracks and diaclases of the ground, the ambient temperature and especially the accuracy of the mixture with the ROAR expansive cement water.

Diameter (cm) V (dm3) Density (Kg/dm3) KG consumption (in a linear meter)
28 0,62 2 1,23
30 0,71 2 1,41
32 0,80 2 1,61
34 0,91 2 1,82
36 1,02 2 2,04
38 1,13 2 2,27
40 1,26 2 2,51
42 1,39 2 2,77
45 1,59 2 3,18
50 1,96 2 3,93