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Crack Sealing Configurations and Cost-Effectiveness Analysis

Posted by Shell Zhang on

Cost-effectiveness is often the preferred method of determining which materials and procedures to use. We reviewed a cost effectiveness study on crack sealing materials for a U.S. State DOT. The study involved the construction of four experimental test sites within larger crack sealing projects. These sites include combinations of two sealant materials and six sealing techniques. The two materials were Right/Pointe and Maxwell. All hot poured crack materials met the ASTM D6690 standard. The crack sealing technique included both non-routed and routed methods. Non-routed methods consisted of the Simple Band-Aid and Capped configurations. The Band-Aid configuration used a V-shaped or U-shaped...

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To Rout Cracks or Not Rout Cracks?

Posted by Shell Zhang on

There has been a lot of research done on whether it is better to rout cracks or not. To make a long story short it is not clear cut. The long story is that it depends on whether you are taking a short or long-term view. Like many things a higher up-front investment gives you a longer term outcome. A lot of research shows that cracks that are routed last longer than cracks that aren’t routed. The trade-off is that it is more expensive to rout cracks for several reasons. First of all you have a higher labor, time, and...

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What is Bitumen and How is it Made?

Posted by Shell Zhang on

Origins Bitumen is defined in the Oxford English Dictionary as ‘a tarlike mixture of hydrocarbons derived from petroleum naturally or by distillation, and used for road surfacing and roofing’ (Oxford University Press, 1996). It is widely believed that the term bitumen originated in the ancient and sacred language of Hindus in India, Sanskrit; in which jatu means ‘pitch’ and jatu-krit means ‘pitch creating’. These terms referred to the pitch produced by some resinous trees. The Latin equivalent is claimed by some to be originally gwitu-men (‘pertaining to pitch’) and by others to be pixtu-men (‘bubbling pitch’), which was subsequently shortened...

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Who Were The Three Greatest Road Engineers?

Posted by Shell Zhang on

Jack Metcalf John Metcalf was the first of the great road builders during the Transport Revolution.  He was a remarkable man, who had been blind since the age of six, but went on to build about 300 km of turnpike road, mainly in Lancashire, Derbyshire, Cheshire and Yorkshire, in the period 1765 – 1792. His nickname was ‘Blind Jack Metcalf’. Metcalf believed that a good road should have good foundations, be well drained and have a smooth convex (rounded) surface to allow rainwater to drain quickly into ditches at the side of the road.   Metcalf established his reputation as a...

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10 Most Common Types of Asphalt Concrete Maintenance Treatments and Terminology

Posted by Shell Zhang on

Crack repair with sealing: A localized treatment method used to prevent water and debris from entering a crack, which might include routing to clean the entire crack and to create a reservoir to hold the sealant. It is only effective for a few years and must be repeated. However, this treatment is very effective at prolonging the pavement life. This method includes the following three crack repair methods : Clean and seal: Used on all types of cracks, it involves using a hot air lance or compressed air to blow out the debris in the crack, then filling with a sealant. Saw and seal: Involves...

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