Is Dynacem suitable for reinforced concrete? How to use Dynacem for demolition of reinforced concrete foundation / foot / slab?
How much Dynacem do I need ? How to calculate Dynacem consumption for reinforced concrete demolition?

Dynacem is often used for demolition of reinforced concrete (RC) elements and structures.

Dynacem breaks concrete but it is however not able to break the steel bars of diameter above 10-12 mm. It is necessary to remove cracked concrete pieces from between the steel bars after Dynacem reaction. Final removal of cracked concrete is performed with excavator (hammer/bucket attached) or with pneumatic/hydraulic/electric hand operated hammers.

Dynacem helps to avoid explosions and heavy hammering of the concrete. It eliminates shock waves and strong impacts. Demolition can be performed with less noise, vibrations and emissions.

Demolition of rectangular RC element begins from drilling circumferential row of vertical holes 16 cm away from the edge of the element (16 cm = 4 diameters of the hole). It is best to fill every other hole in one step and fill remaining holes next day.
6 hours after filling the circumferential holes are safe and internal holes can be drilled in square drill pattern to break the interior of element.
Circumferential reinforcement is exposed and released (by expansion of Dynacem in outer holes alone or with a little help of a hammer), and should be cut.
Internal holes are filled. 1 (best) or 2 outer rows of holes are filled in one step. Another 1-2 rows are filled up every 1 day.
Removal of cracked concrete begins on day 3rd or later. As long as the cracks grow, the later concrete removal begins, the more the structure will be damaged by Dynacem and the easier it will be to remove.

Hole diameter: 40 mm (32-40 mm for lightly reinforced concrete).
Drilling depth: 95-98 % of element height.
Hole spacing: depends on method being used for the final removal of pre-cracked concrete. Typical cases are listed below.
Hole spacing at hole diameter 40 mm, in heavily reinforced concrete, when final removal of concrete is performed with:
- excavator hammer: 40 x 40 cm (Dynacem consumption 14 kg/m3 of concrete),
- pneumatic/hydraulic hammer: 30 x 30 cm (Dynacem consumption 25 kg/m3 of concrete),
- light electric hammer: 20 x 20 cm (Dynacem consumption 54 kg/m3 of concrete).
Hole spacing at hole diameter 40 mm, in lightly reinforced concrete, when final removal of concrete is performed with:
- excavator bucket: 40 x 40 cm (Dynacem consumption 14 kg/m3 of concrete),
- pneumatic/hydraulic hammer: 33 x 33 cm (Dynacem consumption 20 kg/m3 of concrete),
- light electric hammer: 25 x 25 cm (Dynacem consumption 34 kg/m3 of concrete).
Hole spacing at hole diameter 35 mm, in lightly reinforced concrete, when final removal of concrete is performed with:
- excavator bucket/hammer: 35 x 35 cm (Dynacem consumption 14 kg/m3 of concrete,
- pneumatic/hydraulic hammer: 30 x 30 cm (Dynacem consumption 19 kg/m3 of concrete),
- light electric hammer: 22 x 22 cm (Dynacem consumption 34 kg/m3 of concrete).

To find galleries of pictures demonstrating demolition of reinforced concrete elements and structures click here.