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...
Slab Thickness Design of Heavy Industrial Concrete Pavements
The design of concrete pavements for industrial facilities (truck or container terminals, industrial storage, harbours) has been based either on design catalogues or charts This paper introduces a numerical solution, based on the theory of elasticity expressed in form of series. The reason is that such pavements carry very heavy...
Surface Characteristics and Driving Comfort on two Swedish Concrete Roads
In Sweden there is an increased interest in the performance based specifications of concrete roads, such as wearing resistance, friction and noice. Recently two concrete roads have been constructed with the special intention to improve the surface characteristics. Both roads were constructed with concrete that is resistant to wear and...
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...
Upgrading of Porphyry 04 Crushed Stone Sand By Stabilization with Cement
One way of upgrading crushed stone sand is to add cement, for the purpose of using it in a foundation layer. The authors report on their experience with stabilization by means of cement and with the use of the material in the foundation of a motorway work site. The previous...
Wear Resistant and Noise Reducing Concrete for Road Pavements
Rutting, depending on the wear of studded tyres, is a problem in the Skandinavian couritiis. Concrete pavements have a good wear resistance. In Ai.ustria they have recently developed a low noise concrete with small aggregate size and exposed aggregate. Earlier experiences have shown that the wear resistance of concrete is...
Enlargement Works at the Airport of Liege (Belgium)
The airport of LiOge in Belgium has been the subject of major works for several yearjSince the country was regionalized a few years ago, the Wlloon Region has invested over 1,5 milliard Bel g ian francs. Several new buildings have already been constructed.rThe most spectacular wor, however,lTs the enlargement of...