Lagan Construction Materials secured the contract to produce, haul and lay 50,000m2 of CBGM material on the N17 Gort to Tuam dual carriageway. The section of work on the Southern end of the scheme was 26km long of average width 11.0m for both the North and Southbound Carriageways. The CBGM layer was designed to have a layer thickness of 180mm. There were also 8 rolling crowns.
A RAPID Trakmix 250 plant and compound was set up centrally within the section and the stockpiled site won aggregates were stockpiled here.
Main contractor supplied Lagan Construction Materials with the crushed and screened CBGM aggregate to required grading.
We utilised an independent Lab on site to ensure materials being used for production were within the required grading envelope, and to verify moisture contents.
Production figures varied between 1,000 – 1,800 tonnes per day.
The mixing Plant was capable of continuously mixing 250t/hr and is specifically designed for mixing with an all-in type aggregate and fully automated production software and storage. Mixing of CBGM was carried out in accordance with LCM Factory Production Control manual.
Haulage to laying location was via a fleet of 30T Articulated Dumpers and laid through a Vogele Super 1900-3 paver which has been factory modified for specific laying of CBGM.
Compaction was carried out by 2nr Hamm HD90 Twin Drum Rollers and an HD12.
Induced joints were cut into the fresh material using modified vibrating plates and inside of joints coating with K1-40 bitumen emulsion, with the finished surface received a coat of K1-40 and the end of each shift as a curing agent.
All test results (density and Cube strength) passed and no material was rejected or required removal. Lagan Construction Materials were able to offer the main contractor cost savings by gradually reducing the cement content as confidence grew with test results.