A graded angular material, either crushed rock, crushed slag or recycled aggregates, that meets the requirements of Clause 803 - Specification for Highway Works.
Type 1 Sub Base is generally a 40mm graded to dust material that is laid and compacted to form a level stable construction layer as a platform for asphalt or concrete. It is typically used in the construction of highways, car parks, footways and hard standing areas.
Additional info
Any construction application requiring a firm sub-base needs Type 1. The load-bearing function and capacity of even a 100mm sub-base should not be underestimated. If retained then can turn a failing, rut-prone sub-grade into a effective surface.
MOT Type 1 otherwise known as DOT Type 1 is the most commonly used DfT approved sub-base in the construction sector. Named after the DfT specification for granular sub-base it must comply with the Specification for Highway Works, clause 803 (SHW 803).
Made from crushed rock or recycled aggregate. The product is crushed to generally 40mm down to dust creating an aggregate containing a range of particle sizes that is easy to compact with excellent load bearing qualities. This product is not to be confused with scalpings which have a higher fines content and subsequently less load bearing capability.