Any wet formed crack inducing should take place before rolling. Moisture is added over the course of at least 3 days allowing setting of the concrete.
At first, the water is to be sprayed in a fine mist in order to prevent wash-out of the concrete surface. Pneumatic tyred rollers PTR can be very effective for providing a smooth, tight surface. RCC as a running surface Roller compacted concrete is a relatively dry, no-slump concrete which is laid using asphalt paving equipment.
It is mixed in a concrete mixing plant on or near the job site. In this location, the highest possible compacting intensity is achieved, as the mix is prevented from yielding to the front.
Settings of Compacting Systems in the Screed Tamper stroke: 7mm Tamper speed: 1, — 1, rpm Pressure of pressure bars: 80 — bar depending on the concrete properties. Ashfield agreed this is good practice and says that it is a common requirement from the UK Highways Agency, with cement bound materials.
Finally, the concrete layer is compacted with rollers.
If the material contains too little water, optimal compaction of the concrete is not possible. Test strips are a good way to demonstrate that the density, surface requirements and joints are meeting the required performance.
Materials producers do already use gyrator compactors to help them design RCC mixes.