What is concrete?
Contrary to popular belief, concrete and cement are not the same thing; cement is just a component of concrete. Concrete is made up of three basic components: water, aggregate (rock, sand, or gravel) and cement. Cement, usually in powder form, acts as a binding agent when mixed with water and aggregates. This combination, or concrete mix, will be poured and harden into the durable material with which we are all familiar. Read more about concrete here.
Basic requirements for the prefabrication factory
- Participation in Graphic Concrete Technology Training
- Understanding the instructions which must be carefully followed
- Knowledge and facilities to produce fine exposed aggregate concrete surfaces
- Facilities and equipment to use high-pressure washing with water
- High-quality moulds for horizontal casting
- The use of a vacuum table is recommended but not necessary
Casting sample slabs
1. Storing and handling of papers
The paper must be stored in a dry, warm space protected from sunlight, moisture, oil, dirt and dust. Handle the paper carefully to prevent wrinkles or creases. When stored in its original package, the paper can be used for one year from the production date.
2. Preliminary tests and trial castings
Technology Training must be conducted prior to commercially using the Graphic Concrete technology. This helps ensure a high-quality end result and production efficiency. The training includes trial castings as well as large scale production. Preferably the training will be conducted at the production facility by a certified trainer. Smaller initial tests can be carried out without training.
Sample slab production begins with cleaning the mold. The mould should have an even and clean surface. Even the smallest irregularities or contaminations on the mould surface will be visible on the concrete surface. Use an industrial vacuum cleaner to remove all loose dust and sand particles. Do not use mold oil or release agents.
4. Setting the mould edges and building the mold
Press the paper tightly against the surface of the mold table. As little air as possible should remain between the paper and the table surface. When casting a small sample the paper can be locked under the mold edges. With larger samples the paper should be free floating; cut slightly smaller than the mold on all sides in order to allow the paper to flatten out as the concrete is cast on top and air pushes out from underneath the paper.
5. Casting and compacting the slab
Pour the concrete mix. When making a larger sample, start pouring from the middle and move outwards in order to allow the weight of the concrete to push out possible air from underneath the mpaper. Use external vibration for compacting the slab in the normal way. Use sufficient compacting time but keep it as short as possible. Self-compacting concrete may also be used.
6. Exposing the graphic concrete pattern
After the concrete has cured, de-mould and remove the paper. Pressure wash away the unset cement with water. A graphic concrete surface can be sealed and anti-graffiti treated in a normal manner.
More specific instructions available on request. Contact us if you are interested in producing Graphic Concrete.