Cement Treated Aggregate
This is cement mixed into the aggregate before placing onsite, to provide a high strength subbase for roading often using an inferior aggregate or where site access is limited for stabilisation on site normal aggregate can be used. This provides a fast and effective onsite solution.
Road Stabilisation
This is where cement or other binding agents are “hoed in” on site to enhance the strength of the sub base of the road.
Road Recycling
A method which is becoming more common on failing roads is to add a layer of aggregate to the top of the road then add cement or other binder. Then hoe the road including the bitumen surface and lower sub-base to recycle the existing materials. This is a quick and cost effective solution as it reduces the need to remove existing material and replace it with new. By the reuse of existing materials the life of New Zealand’s quarry resources will be extended.
Concrete Roads
These have been built since the 1930's in New Zealand and are still in service today. Modern concrete roads offer exceptional durability with very low maintainance and come in 3 different types.
PCP – Plan Concrete Pavement. No reinforcing generally thicker pavement with transverse saw cut joints at 5 m centers and longitudinal joints down lane lines. Good for rural highways where there is a dedicated batching plant onsite. Least expensive option.
JRCP – Jointed Reinforced Concrete Pavement. Lightly reinforced between joints with 665 mesh to increase distance between transverse joints out to 7 or 8m and designed to crack itself (irregular crack) at around the 4m mark. Same longitudinal joints down lane lines.
CRCP – Continuous Reinforced Concrete Pavement. No transverse joints, reinforcing is longitudinally continuous and the pavement has self induced fine cracks at about 0.6-1m centers. Same longitudinal joints at lane lines. Most expensive.