In 2005 some 5,500m³ of Leca® Lightweight Expanded Clay Aggregate was specified by consulting engineers Grontmij, Edinburgh to form a new, 1.5m high embankment serving as an approach road in the North Port area of the Dublin Port Tunnel.
The presence of a recently installed high pressure gas main at shallow depths meant that the fill material needed to be lightweight to avoid increased stresses, easy to install in restricted areas and suitable for use in road pavement design for busy trafficked situations.
The design involved excavating below the existing levels and up-filling to the higher finished sub-formation with Leca® Lightweight Expanded Clay Aggregate 10-20mm in preparation for the final road pavement construction. All works were carried out by main jv contractor Nishimatsu Mowlen Irishenco.
The Leca® was shipped to and stored at the port of Dundalk ready for call off as and when required; due to the light weight of Leca® Lightweight Expanded Clay Aggregate, high capacity 55m³ articulated tippers were employed to speed up the rate of delivery and final placement was carried out using a tracked excavators on site.
Leca® Lightweight Expanded Clay Aggregate , is a natural, lightweight, totally inert, expanded clay, fill material, produced in accordance with EN 15732 and is capable of reducing design loads by up to 75% and making significant savings in construction programme.