How do you undertake the repair of a jointed concrete carriageway on one of the busiest motorways in Europe, particularly when a large proportion of the joints have failed and the slabs are floating on a sea of Gault Clay. With differential settlements so severe that there was genuine concern...
The Use of Continuously Reinforced Concrete Overlays in Motorway Maintenance (A Case Study)
Concrete Highway Pavement with Thin Upper Layer Concrete and Concrete Pavement on Short Bridges
For concrete pavements the new thin upper layer concrete construction method, potentially in connection with the method of thick concrete pavement placed on an unbound roadbase enables a 40mm thick upper layer concrete having a maximum aggregate size of only 8mm to be placed instead of a 70mm thick upper...
Ultra-Thin Whitetoppirig Ontarios Experience
Ultra-thin whitetopping (UTW) is one of the newest and most innovative applications of portland cement concrete. The technique entails bonding a relatively thin layer of concrete onto an existing asphalt pavement. This technique was conceived in the United States of America and the first experimental project was built in Louisville,...
Performance of Thin Concrete Overlays in South South Africa
Since 1970, several highways in South Africa were cujistructed in Portland cement concrete, the only design being used was the jointed unreinforced concrete pavements. Due to early deterioration as a result of alkali aggregate reaction, one section had to be overlayed In order to determine the last option, several experimental...
Whitetoppings – Long Term Performance and Recommendations
Field tests have been carried out with thin, high strength concrete overlays (whitetoppings) placed on top of the milled asphalt pavement The aim is to find methods to restore rutted asphalt pavements and iliclease their rutting resistance. The whitetopping was limited to 70 mm. Both plain and steel fibre reinforced...
Elimination of Ruts at Intersections by Means of An Inlay/Overlay Made of Steel Fibre Concrete
To the North of Gent there is an important harbour and industrial zone. Because of the heavy traffic on the road connecting Gent and Zelzate (R4, section J. Kennedylaan), deep ruts have formed in the asphalt pavement, mainly at the junctions. In order to repair these ruts in a durable...
Fibrous Ferrocement – An Ideal Material for Bridge Overlays
The overlays of highway bridges are usually subjected to stresses like impact stresses, longitudinal stresses, due to the application of brakes and wear and tear stresses. The moving loads on bridges have a jumping action due to uneven surface on which they move. This jumping causes shocks and vibrations of...
The Importance of Continuous Slab Support and Load Transfer at Joints in the Performance of Thin Concrete Overlays
Studies on the structural performance of existing Portland cement concrete roads in South Africa (1) have shown that the traffic utilizing these roads is not the pnme initiator of structural failures. Factors such as construction, environment and slab support conditions are predominant in initiating structural failures. However, it is also...
Belgian Applications of Concrete Inlays on Motorways
Today all highways and road managers are confronted with the problem of the rutting of dense asphaltic concrete roads due to the steady traffic increase of heavy vehicles. Consequently, the lifetime of the low speed right lane decreases much faster than the lifetime of the left lane, which is merely...
Rehabilitation of Concrete Slabs by Sifcon-Overlays
A new means for rehabilitation of severely cracked concrete slabs is a thin overlay of SIFCON (Slurry Infiltrated Fibre Concrete). This high strength concrete with an extremely high content of conventional steel fibres (about 10 % of volume) was invented in the USA and further developed by the central laboratory...
Jointed Concrete Pavement Structural Evaluation Overlays Design
In connection with a rehabilitation project, the long-term performances of 15km existing old jointed pavement were comprehensively surveyed. The collected data included visual conditions, roughness measurements, core tests, and FWD defleLtions. By analyzing the FWD measurements, the in situ struchiral moduli were backcalculated, and then, the fatigue damage of existing...
A New Laboratory Test to Evaluate the Shear Resistance at the Interface of Thin Bonded Overlays
The effectiveness of thin bonded overlays depends upon the adhesion level at the interface with the existing concrete pavement. It appears that shrinkage, particularly at the very early ages (18-24 hours), is mainly responsible for delamination, i.e. separation between old pavement and overlay. The present paper discusses the results of...