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Concrete road slab reinstatement (S7.3)


Permitted options, as shown in A5, are subject to the following conditions:

Concrete specification

Concrete road slabs must be reinstated with C32/40 concrete mixed in accordance with MCHW Clause 1001 and using an air entrainment admixture in the top 40 mm (at least) of the road slab. Exceptionally, where agreed, a concrete road slab may be reinstated with an alternative material to suit site conditions, e.g. a high early strength mix may be agreed to allow an earlier re-opening of a heavily trafficked road.
Where concrete is mixed off site, Quality Assurance certificates detailing the specifications against which the concrete has been ordered and supplied must be obtained by the undertaker for confirmation of material quality. Where possible, the concrete should be obtained from a plant that holds a Quality Assurance certificate.
In the case of small openings, a site-batched equivalent to C32/40 concrete detailed in S7.3.2 may be used.

Considerations related to pavement details

Information on the slab type and its condition, joint spacing and the presence of any other features near the proposed excavation should be requested from the authority by the undertaker. If this information is not made available, then an inspection survey commissioned by agreement may be carried out.


All expansion, contraction and warping joints removed or damaged during excavation must be replaced or reconstructed to a similar design, using equivalent materials at the time of permanent reinstatement.


Any existing slip membrane must be reinstated beneath the road slab. A curing membrane must be used above the road slab.
Impermeable polythene or similar sheeting may be used for the slip and curing membranes.
Sprayed plastic film can be used as a curing membrane by agreement.

Texture depth

For small openings, narrow trenches and other openings less than 1 m wide, reference must be made to S2.6.1(2) and Table S2.5 and Table S2.6.
For all other excavations the authority must be consulted and a method agreed. The finished surface must comply with Table S2.5 and Table S2.6.

Opening to traffic

The cured road slab may be opened to traffic as soon as a compressive strength of 25 N/mm² has been achieved. The compressive strength may be measured on samples cured under conditions representative of the site conditions.


Corner and edge cracking and joint damage within the trench area must be repaired as a part of the reinstatement works.