Texture allows the natural essence of the concrete ingredients to be expressed, provides some scale to the mass, expresses the plasticity of the concrete and improves the weathering characteristics.
A variety of textures can be achieved. Four major factors should be considered in choosing a texture:
- The area of the surface. Coarse textures are difficult to use on small areas.
- The viewing distance. From a greater distance, different textures will provide different tonal values. Determining the normal viewing distance in the final use will impact which textures and sizes of aggregates should be used.
- The orientation of the building’s wall elevation. This siting determines the amount and the direction of light on the surface and how the panel will weather.
- Aggregate particle shape and surface characteristics. Both the shape and surface characteristics determine how the surface will weather and reflect light.
Three key levels of exposure that are used in creating a finished appearance are:
- Light exposure involves removing only the surface skin of cement and sand. This sufficiently exposes the tips of the closest coarse aggregate.
- Medium exposure requires further removal of cement and sand to cause the coarse aggregates to visually appear approximately equal in area to the matrix.
- Deep exposure requires cement and sand to be removed from the surface so the coarse aggregates become the major surface feature.
For more information, contact a PCI Certified Manufacturer.