The most common reason for pavement failure is moisture penetrating the surface.
Cracks in pavements allow moisture to penetrate the surface which causes pavement material failure. Failure to seal cracks results in further cracking, potholes and eventually a major pavement breakdown, leading to unnecessary expensive repairs.
To minimise the water infiltrating the pavement base, crack sealing with a hot polymer/rubberised bitumen sealant is required, preventing future pavement problems.
Crack sealing is an extremely economical way of maintaining pavements. It is very cheap and effective when compared to undertaking other more extensive works such as resurfacing and reconstructing.
Crack sealing is a practical and cost effective measure and is part of any good pavement management program for all roads.
Who uses crack sealing?
Crack sealing is used world wide, extensively in countries including France, England, Germany and USA. States such as Texas, USA spend approximately $US11m per annum on their crack sealing program.
In Australia, crack sealing has been used increasingly more over the past two decades. Many local governments in all states and territories now advocate crack sealing as a key element of their maintenance program. Both small and major contractors have also been using crack sealing more as results have shown that they are able to have their repairs and new overlays last longer.
The results here and internationally show that crack sealing is a proven way of effectively protecting and extending the life of pavements.
Causes of Asphalt and Concrete Failures
Movement of the pavement
Oxidation of the binder
Upward reflection of underlying pavement
Overloading of vehicles and continued traffic use
Depth of pavement
A Maintenance Program will save you millions
An Average Council has over $300m worth of assets in roads
A systematic maintenance program is essential to extend the life of pavements
Early maintenance intervention is vital
Crack sealing is a key element in slowing down the deterioration process
Extending the life of pavements can save you millions in the long term
Early intervention is vital in prolonging the life of pavements. Once you can see pavement failure on the surface, the rate of deterioration accelerates. Crack sealing is a key element in early intervention as it slows the deterioration process and can significantly add to the life of a pavement, maximizing your asphalt investment
Crack Sealing Applications
Used on smooth asphalt, reducing noise and improving skid resistance
Used on chip seal surfaces to ensure better penetration into cracks
Used on wide cracking to provide sufficient bondage on either side of the crack
The key qualities of crack sealing products are their flexibility, suitability to local weather conditions and that they are applied hot and are skid resistant.
An effective crack sealant must have excellent torsional recovery within the crack, withstanding repeated expansion and contractions in the pavement. This flexibility must exist over a wide range of temperatures and have a high softening point to ensure that the product will not bleed in hot conditions.
Suitable plant with heating capabilities is necessary when undertaking crack sealing operations. As the sealant is classified as dangerous goods, appropriate signage and qualifications are required. Ideally the works should be done by an all-
You want asphalt repairs to be done with the right techniques to ensure they last as long as possible. However, even with the right techniques used, often patches fail as they have not bonded with the existing pavement and water and debris enter the surface. Crack sealing around the edge of new patches forms a waterproof bond and increases the longevity of the repairs.
When overlaying existing asphalt, it is vitally important to crack seal prior to works to prevent reflective cracking. If new asphalt is laid on failed pavement, the cracks in the base will undermine the new overlay and produce new cracks.