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Rehabilitation of the Maleny Kenilworth Road

Projekt Informationen

Baumaßnahme

Resurfacing of Maleny Kenilworth Road

Ort

Witta, QLD, AU

Auftraggeber

Transport Main Roads Queensland

Planung

Downer Mouchel

Bauausführung

Downer

Bauzeit

27 July 2016

Projekt Details

Aufgabe

This location consists of a two lane, two-way road with existing Jointed Plain Concrete Pavement. The road has a steep gradient and is trafficked by a mixture of vehicles ranging from light through to heavy vehicles, including B double trucks. The pavement had extensive cracking and settlement along this section of the road. Due to the amount of failures the road surface had become excessively rough.

To improve the ride quality of the road, several options were available:

• Replacement of all damaged slabs

• Diamond grinding of the surface

• A thick asphalt overlay

• A thin asphalt overlay

In July 2016, the asset owners chose to improve the ride quality by way of a thin 50 mm asphalt resurfacing of the concrete pavement. However, concerns overachieving a lasting bond and the onset of rapid reflective cracking had to be addressed.

Due to the severity of the cracks in the existing pavement, a thin asphalt overlay on its own would not be expected to resist the rapid propagation of existing cracks or expansion joints. In addition, no funding was available for any rectification of existing pavement defects, such as slab replacement, slab jacking, concrete stitching, or crack sealing.

Lösung

To actively delay reflective cracking and protect the pavement, HUESKER’s SamiGrid asphalt reinforcement was utilised between the existing concrete pavement and the new 50 mm (AC14) asphalt overlay. SamiGrid consists of a specialised asphalt reinforcement grid engineered from alkali-resistant high-modulus polyvinyl alcohol (PVA) polymers in combination with a nonwoven backing. The PVA grid performs the primary function of effective retardation of reflective cracking. Saturation of the nonwoven backing with bitumen allows SamiGrid to also perform a sealing function over the slabs. Both the grid and the nonwoven are pre-coated using polymer-modified bituminous coating (with a minimum of 65 % bitumen content) to enable an optimum bond between the underlying concrete and the overlaying asphalt layer. Combined with added high resistance to construction damage during asphalt paving operations, this makes SamiGrid an ideal solution for rehabilitation of concrete pavements with an asphalt overlay.

Vorteile

In 2021, five years after the surfacing, the asphalt overlay was found to be crack free. The performance was found to be exceptional, well exceeding the initial expectations. Despite the severity of the untreated cracks and defects in the underlying concrete pavement and the choice of a thin asphalt overlay, no existing cracks or concrete joints have propagated into the wearing course. The use of SamiGrid as a solution in this section has allowed the asset owner to improve the ride quality of the existing pavement, whilst also considerably extending its service life and delivering a more sustainable construction.