Composite Geogrid for Mandalong Mine

Geogrid for mining project

Operated by Centennial Coal, the Mandalong South Surface Site development began in 2017. This project was awarded to established mining infrastructure contractors Daracon, who were brought in to build additional access roads and provide modified turning lanes along an existing route.

Mandalong Mine is located in the Newcastle Coalfields in NSW, and the project involved the construction of a 1.8 kilometre long access road and the provision of a channelized left turn and basic right turn intersection on Mandalong Road.

Prior to the road pavement taking place, the soil needed stabilisation, strengthening and reinforcement. Jaybro’s GEOmasta geosynthetic division supplied a significant quantity of mastaGRID Composite geogrid for this purpose.

The Challenges

Daracon successfully saw this project through to completion in late 2018, despite a series of hurdles. Working with design changes to drainage infrastructure due to the migration of a threatened plant species, as well as restrictions on heavy vehicle movements, coupled with the inclement weather presented a series of challenges to overcome.

However, the key challenges of this project were the existing poor condition of the soil, combined with persistent wet weather. Daracon’s workforce was compelled to adapt to the lengthy periods of rain and at the same time, work to remediate the unfavourable ground conditions.

The project engineers identified GEOmasta as a supplier of choice for geogrid that could help solve the prevailing soil issues by providing additional strength and reinforcement.

Jaybro’s Solution

Jaybro was awarded the supply of geosynthetics to the Mandalong South Surface Site project. mastaGRID Composite Geogrid was used to solve two different issues. The geogrid helped to give additional strength and separation between general fill and natural material. Additionally, it was used as a separation and reinforcing layer between the natural alluvial soil and a rock drainage blanket.

Workers reported that mastaGRID Composite geogrid was simple to use and install on site. “The material was easy to use and simply rolled out using an excavator and labourers. Rock or soil was placed directly on top and tracked in at 300 to 500 mm layers using a dozer.”

mastaGRID Composite is an engineered geogrid designed for soil stabilisation, separation and reinforcement applications. mastaGRID Composite is manufactured from polypropylene through the process of extruding, combined with longitudinal and transverse heat stretching. Strong yet lightweight mastaTEX geofabric is then heat bonded to the grid, to ultimately form a sound composite structure.

It is designed to improve load capacity and prevent water damage in road construction and renovation. It has high temperature resistance and resists cracking, which therefore extends the life of asphalt pavements.

The Mandalong South Surface Site project has an estimated value of $4.8M.

Product Specs

• Grade: 30/30
• Size: 3.95m x 50m
• Material: PP/PET Non-woven

Key Data

• GGCB3030 Value: $47,000
• Installed: June 2017
• Project Completion: Late 2018