What is Claycrete and how is it different?
Claycrete is a liquid chemical additive which reacts with only the clay fraction of a material. Long after the product has biodegraded the clay will remain in its stabilised state. The improved properties of the clay make it suitable for use in higher portions in road materials.
Clay has been stabilised in the past by the use of lime but the process is expensive and application and mixing is difficult.
Claycrete is unique because the stabilisation does not depend on the presence of a residual product. After the reaction period is completed the stabilised clay is the remaining binder.
Where a process depends on the introduced product acting as the binding agent there will be progressive loss of benefit due to leaching. Additional loss is caused by the mechanical stresses resulting from expansion and contraction of the untreated clay.
A well bound pavement is what every road builder aims to achieve because a road that is low in void will be strong and durable. Road builders in Australia most commonly use cement as a binder and this practice has been relatively successful, but it is too expensive to apply this solution to every problem or on a large scale.
Clay materials have compromised many road building projects because of their unstable nature when exposed to moisture. It is common practice to remove these materials from road projects often at great cost, just as it is common to stop digging when you encounter gravel with too much clay.
Clay can be used in many instances as an affordable binder in place of cement, but it must be stabilised to eliminate the well known problems with moisture.
In one treatment Claycrete stabilises clay, allowing the use of material that would have once been left behind or removed. The presence of additional clay reduces void and improves the binding of the pavement materials. Traditional specifications of low plasticity material impose costly limitations on material sources.
The costs associated with sealed and unsealed road networks can be reduced by healthy margins by tackling the age old problem of clay with a new solution.
Roadworks that have been constructed using a clay gravel stabilised with Claycrete have improved noticeably in key areas.
Benefits reported by clients include:
- Clay gravels are often easier to find. Many pits can be re-used because they were closed as soon as too much clay was reached.
- Clay gravels are usually cheaper to buy because they are often viewed as inferior product.
- Stabilised clay materials produce high CBR’s. This translates to a reduced pavement thickness for the same strength.
- Treated materials are easier to work.
- Treated material requires less water to behave as if optimum moisture content has been achieved.
- Treated material requires less compactive effort to achieve compaction levels.
- Unsealed roads will need less routine maintenance because the treated material is more durable. Less raveling takes place because the pavement is better bound.
- Seals need less maintenance because the pavement is stronger.
- Seals will adhere readily to a treated surface.
- Treated roads can be left longer prior to sealing, allowing better inspection and savings by accumulating areas to be sealed.
- Soil strength
- Soil densities
- Soil compaction
- Pavement life
- Water resistance
- Wear resistance
- Plasticity index
- Abrasion loss