PolyCom DPP pavement restoration trials have indicated strength and durability improvements realised in asset management cost savings in the longer term.

BioCentral reports on exhaustive trials it has conducted over the past four years.

Recent reports from trials conducted on Australian roads confirms a long-held belief among road construction experts that road deterioration could be substantially reduced by the use of Dry Powder Polymers in the pavement materials.

The reports follow the successful trials conducted with a new DPP product PolyCom and indicate that every dollar invested to improve specified pavement materials by the addition of the new product saves significant future rehabilitation costs.

PolyCom was developed in South Australia by BioCentral Laboratories Ltd as an enhancement product to water performance to improve pavement compaction and stabilisation for road materials. During development, independent studies were commissioned and undertaken by Bob Andrews (Infratechno Consultants) a recognised specialist in the area of stabilisation of road pavements.

These ongoing studies indicate that PolyCom can limit the rate of surface deterioration and provide increased wear and dust resistant in unsealed roads, remote airstrips and hard stand areas in addition to decreasing rutting development in sealed pavements thereby prolonging surface correction treatments.

PolyCom accomplishes this by improving the binding and compaction characteristics of water to create greater efficiencies in achieving superior pavement compaction. PolyCom treated water impregnates the material thoroughly, liberating the fine particles within the material. Granular materials are then coalesced to facilitate the inherent pavement fines and crushed stone to slip into a more tightly bound compacted pavement.

The process allows easier mixing, ensuring a more homogenous material which is essential for optimum compaction and the procedure delivers a more durable road surface or base and thus reduces the need for major and more costly repairs later.

Commenting on his findings on the use of PolyCom, Bob Andrews says, "Data has shown that PolyCom provides higher material density with less compactive effort, thereby having the potential to subsequently increase longevity of the pavement and therefore reducing the requirement for repeated and costly maintenance during the road asset lifetime."

Bob says that ideally PolyCom is applied during construction stage which will reduce future maintenance requirement costs, but if problems are encountered in roads not treated with PolyCom, the first rehabilitation procedure should be applied early and when the pavement is in relatively good condition with only slight wear or erosion problems.

Alternately, when the PolyCom treated water is graded in or mixed at the pug mill the lubricating effect facilitates the movement of particles within the working depth during the compaction process to give increased density with less passes of compaction equipment.

The PolyCom treated water is held within the working depth of material for an extended period reducing the need for periodic re-watering during the construction period and ensuring minimal risk of shrinkage cracking in expansive clays for instance. Acting as a binder PolyCom also reduces the dust emissions associated with road construction process making the use of the product an economical and ecological alternative to current construction practices.

The higher densities achieved within the material increases its modulus through a combination of increased internal friction and anionic bonding of the fine particles within the material thus lowering the permeability of the material and therefore reducing the potential for water ingress into the sub-base, which is considered the leading cause of degradation of a carriageway.

PolyCom has also been applied as an asphalt sub base underlay. It is also quite feasible to repair or prevent the recurrence of distress pockets or cracking on sealed roads with total consistency to the rest of the surface.

"PolyCom is preferably mixed at the pug mill or insitu using recycling machines to achieve materials specification during construction or applied in the water truck to correct compaction and stabilisation deficiencies as distresses develop, with less water and easier optimum compaction achievement."

BioCentral executive brand manager Peter Duffy says: "Four years after the initial application on an unsealed road, it continues to slow overall deterioration, and to reduce the loadings impact on sections of passing lanes nominated for trial."

Peter Duffy says that PolyCom also demonstrated significant reduction in water requirements for each trial project, which is important in an era of critical water shortages, but also means less water cartage and substantial savings on transport costs.

"When PolyCom treated water is introduced into the pavement material either at a pug mill, insitu mixed with road recyclers or in remote areas through a water cart, then blade mixed, it will substantially reduce the quantity of water required overall by up to 50%, sometimes more."

PolyCom is distributed in South Australia, Queensland, and NT by Mining & Quarry Services [MQS]; in Northern Victoria, NSW, Tasmania and New Zealand by Mawsons; and in WA by BioCentral's local office.

The product is also distributed in Southeast Asia by JHT based in Singapore and the Middle East by Specialized Chemicals.

For more information on this product contact: Australia & Export Peter Duffy 0409 001 989 or Mark Holding 0418 897 511; Western Australia: Paul Bright 0488 786 191; Queensland: MQS Phil Turley 0414 185 493; Northern Victoria John Christian 0427 346482 or Keith McDonald 0417 187435