Westminster City Council King Street Low Carbon Trial

See Figure 4 for the comparison between the two specifications:

Current Spec - 750x600mm ASP

Marshalls CAT 2: GVW 3,500kg - 750x600mm ASP

Surface Course: 750x600

Surface Course: 750x600 Joints: Marshalls Pavepoint

63mm

50mm

Joints: Mortar

10mm

6-10mm

Laying Course: Marshalls Pavebed + Primer (Pavebond) Road-base: C8/10

Laying Course: Sand Cement Road-base: C16/20 Sub-base: Existing

50mm

30mm

100mm

75mm

N/A

Sub-base: Type 1

100mm*

Depth

213mm

Depth

155-255mm

Figure 4 - Westminster Footway Reconstruction Comparison Table

*100mm sub-base is optional based on the existing conditions, if the reconstruction of the footway is already on well compacted ground with CBRs greater than 30% this can be omitted. For King Street this was not required. Therefore, the construction depth was 155mm and a reduced depth of 58mm. The only other potential change was to explore if low carbon concrete could be used within the road base.

The drawings below illustrate the difference in specification for the footway construction.

Figure 5 - Drawing of Current Specification – Footway Reconstruction (Scale 1:10)

Figure 6 - Drawing of Marshalls’ Specification (50mm slab Thickness) – Footway Reconstruction (Scale 1:10)

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