Pavement Base Course Reinforced with Combigrid® to TMR MRTS58 Specification

Global Synthetics – D’Aguilar Highway Rehabilitation Project

Pavement Base Course Reinforced with Combigrid® to TMR MRTS58 Specification

Global Synthetics was recently selected by McIlwain Civil to provide a Type 1 Geogrid Reinforcement to the newly introduced TMR MRTS58 specification to be placed above a cement treated base course (CTB) and beneath subsequent unbound granular pavement layers in the above project. The geogrid needed to be placed for reinforcement and a separation geotextile was also required in accordance with the TMR MRTS58 specification.

Global Synthetics offered the high-performance Combigrid ® geocomposite combining the required geogrid reinforcement properties with the necessary Strength Class C and Filtration Class I through VIII filtration requirements in the one layer providing time and money savings through the use of Combigrid®. Many thousands of square metres were supplied to McIlwain Civil Engineering who installed the product successfully.

The Combigrid® product offered the reinforcement as well as filtration/separation properties to meet the demands of TMR and in this case offered the benefit of reducing potential for reflective cracking through the pavement layers from the CTB below.

Combigrid® geocomposite is a combination of a welded geogrid with prestressed bars (Secugrid® geogrid) and an integral nonwoven geotextile, locked between the geogrid bars. Combigrid® provides the necessary performance parameters for construction over weak subgrades and under/within pavements and working platforms including reinforcement, separation, filtration and drainage all in one product. The contractor benefits from the installation of only one product that performs more than one function.

The primary applications of Combigrid® and Secugrid® are:

• construction on weak subgrades

• construction on expansive soils

• controlling differential settlements in roads and railways

• construction of working platforms

• reducing the thickness of a granular pavement layers

• reducing reflective cracking in pavements

Apart from being an economical solution, Secugrid® and Combigrid® provide high installation damage resistance, high stiffness and excellent performance supported by various national and international testing and verification works, studies and field trials.

The use of such Reinforcement technologies available from Global Synthetics is becoming widely accepted as beneficial, effective and an economic means of building technically superior and more economical pavements for roads, working platforms and railroads.

The greater benefit to the community is the environmental benefit through using this Combigrid® geocomposite or Secugrid® geogrid reinforcement. This use reduces the amount of excavation of unsuitable subgrade required, it reduced the quantity of rock required to be imported. What this means is less use of our quarried rock resources and less movements of trucks over our existing road network creating less carbon emissions and extending the life of our current road network.