The motorway A7, also called the "Motorway of Wallonia", was opened to traffic in December 1970. In the vicinity of Mons this motorway carries a very high volume of heavy traffic, which is still increasing. The right-hand (slow) lane is subject to severe rutting, which has affected the deeper layers....
Concrete Made of Building Demolition Waste
In the field of research on secondary materials, an experimental study on the re-use of building demolition waste has been conducted. These materials will be used in Italy, further to decree-laws and regulations, drawn in compliance with the rules of the Community Law 1 9 w93h, ich has already been...
Performance of Concrete Pavement Drainage Systems in Spain
At present Spain has 1600 km of concrete pavements (two lane carriageways). The particular conditions of the climate and the heavy traffic make it necessary to use different measures to avoid joint faulting and voids under the slabs such as dowelled joints, non-erodible base courses, sometimes complemented by joint sealing...
Roller Compacted Concrete Pavements for Port Yards
Roller compacted concrete pavements (RCCP) are favourable for port yards. To develop the design, both the bearing capai-ity and the load transfer efficiency at the joints were studied. An experimental pavement with two different RCCP structures was built: namely, one that follows the ordinary design method for port yards consisting...
Some Characteristics of Polypropylene Fiber Reinforced Concrete
A wide experimental campaign was carried out on concretes with the addition of polypropylene fibers. This way it was possible to obtain useful information on the morphological structure, on the trend in time of compressive strength, splitting tensile strength and impact strength, and on the influence on these trends of...
Air Entraining Agents in Road Concretes and Characterization of the Air Void System in the Fresh Concrete
Various air-entraining agents were investigated for their physicochemical characteristics and for their foaming power. Correlations were found between this power and the parameters characteristic of entrained air. These parameters were determined on the fresh concrete using the DBT "Air Void Analyser". Air-entrained concretes have a water absorption very similar to...
Noice Reducing Exposed Aggregate Surfaces – Experience and Recommendations
In 1990 a technique for building pavements with a noice reducing concrete surface was developed in Austria. The top layer contains aggretate with 8 mm maximum size. The surface is sprayed with a retarder and brushed the next day to expose the aggregate. This technique has been used on 120...
Flexible Concrete Pavements
The strength of flexible pavements is more or less at the limit of design, and only minor improvements in allowable contact pressure can be expected. Major increases in vehicle weight on flexible pavements is only possible by increasing the number of axles or by increasing any extra contact area (larger...
Laboratory Tests on Thin Bonded Overlays
The "technique of thin bonded overlays" has been applied to restore damaged concrete pavement surfaces. In this article results from laboratory tests concerning different combinations of repair mortars and several support concretes are piesciuted and discussed. Bond strength of the overlay to the supporting concrete has been assessed by means...
The Reuse of Old Pitch Containing Asphalt in Cement Bound Base Courses Depending on the Level of Harmful Substances
Large quantities of old asphalt containing varying admixtures of tar/pitch are produced during the renewal of asphalt roads. These pitches contain environmentally relevant substances such as pnlyr.yr.lic aromatic hydrocarbons (PAHs) and phenols which must not be allowed to leach out into the ground water. The intention is to bind the...
Use of Porous Bases for the Drainage of Concrete Pavements in the USA
In the United States, many States are using free draining porous bases under new portland cement concrete pavements. These porous bases are intended to remove infiltrated surface water, which cannot be prevented from entering the pavement structure. The porous bases used in the United States have coefficients of permeability ranging...
Performance of Roller Compacted Concrete Pavements in Spain
Roller compacted concrete (RCC) began to be used in Spain in 1984 on roads bearing heavy and medium traffic. Up to now more than 250 km of RCC pavements have been constructed. A significant portion is subjected to the combined effect of heavy traffic and servere temperature gradients. Joints are...