Gatwick Airport, Stand 50, North Terminal

Client: BAA plc. Project: approximately 1,000sqm external refurbishment. Main contractor: Dyer and Butler, Gatwick's term contractor. Also on site: Foster Yeoman Ltd.

Overview

BAA plc selected a jointless grouted macadam surface as the refurbishment solution for Gatwick Airport's busy Stand 50 at its North Terminal. Approximately 1,000 square metres were installed.

The requirement

Aircraft stands need a surface that resists fuel, drains predictably and has no joints to fail under repeated heavy loading. Stand 50 is in constant use, so the time between taking the stand out of service and handing it back was the governing constraint.

Why grouted macadam

The system had already been used for over a decade at Copenhagen Airport as a jointless, fuel resistant surface material well suited to aircraft hardstandings.

The deciding factor at Gatwick was early strength gain. The proprietary microsilica based mortar typically gains 87 per cent of its 28 day flexural strength within 24 hours, and achieved a three day laboratory determined mixture stiffness at 20C of 6.9 GPa. That meant the stand could be reopened to aircraft after 24 hours.

Design and specification

The proposal replaced the concrete blocks, bedding sand and contaminated regulating layer with a 50mm surface course on an interlayer of high modulus binder course.

Installation

Dyer and Butler, Gatwick's term contractor, laid the porous asphalt support layer to close tolerances under CIP supervision. CIP supplied and laid the mortar to the porous layer using its specialist installation team.

The surface was then grit blasted to give a safe, non slip finish for servicing staff and passengers, particularly in wet weather. Those works were carried out by Specialist Surface Preparation Ltd, who removed the excess afterwards with a magnetic sweeper to leave a smooth, clean and durable finish.

Outcome

The stand reopened to aircraft 24 hours after laying. Gatwick Airport Ltd and BAA's pavement team allowed the condition of the surface to be monitored afterwards. Nine months after installation the client reported its successful performance and expressed satisfaction with the solution.

Photographs from the original CIP project records. The system was supplied under the Densiphalt name at the time of these works and is now supplied as Confalt through Contec. This was a CIP installation, and the grouted macadam contracting capability now sits with Globe Civil Engineering.