A very favourable result emerges from the assessment of the soundness of structural arrangements adopted and developed over the past ten years (3rd International Conference at Purdue, April (985). After briefly reviewing this positive achievement resulting from closely concerted action of road managers, practical engineers and researchers, the authors more...
Side drainage and sub-soil drainage layer operation and performance
Spanish realizations of steel fiber pavements
The development of the steel fiber reinforced concrete pavements has experienced a big apogee in Spain in the last three years. The object of this work is to display the most important realizations made in the field of roads. harbours, airports, etc., analyzing their characteristics and behaviour. ROADS - Base...
Economic appraisal of cement concrete versus asphaltic concrete pavements
1. Introduction Since 1962 no cement concrete had been used in the governmental road sy~tem as a paving material. After 1975 the need to use this material again was felt more and more. Somewhere about 1982, during the decision making period regardi~g the type of pavement to be chosen for...
Structural design of concrete pavements
Under present economic conditions the use of bitumen is being reduced as much as possible. For more than twenty years the application of semi-rigid pavements has revealed the drawbacks but also the advantages of such structures. The chief advantage is their low cost, which can be further reduced if the...
Survey of drainage methods for concrete road pavements
In the Federal Republic of Germany, as in other countr~ es, concrete road pavements have in recent years been affected by deteriorative damage which is attributable to Lhe presence of wa ter in the pavement. lnvestigations which the Federal lnstitutefor Highway Englneerlng (Bundesanstalt für Strassenwesen) started in 1981 aimed at...
Effect of the distribution of air entrained in superplasticized and high workability concrete for traffic areas
For obtaining a high degree of resistance to the action of frost and de-icing salts on concrete, it is essential to have an adequate content of air-filled micropores adjusted to the amount of fine-grained mortar in the mix. With QOI1ventional road concrete, correctly made, it can be presumed that if...
Noise protection walls (Design and construction)
Since 1972 between 250,000 and 300,000 m2 of acoustic screening (noise reduction) barriers have been built in France, i.e., 70 - 80 km of such structures of medium height (2 - 6 m), along the roads. They have been installed under a policy of both road and rail traffic noise...
Fatigue experiments for the design of plain concrete pavements
In the design of plain (unrelonforced) concrete pavements the influences of traffic and temperature, among others, are taken 1.nto account. These sue j ect, the pavements to load var1.a1:.l.onBse.cause the traffl.c comprises vehicles W1.th widely differing wheel loads, the loading pattern due to it is very erratl.c: the frequency dnd...
Construction and performance of concrete pavements in Bavaria
For economic and environmental reasons various motorways in Bavaria" have been provided with concrete pavements in recent years. In this form of construction the concrete slab and cement-bound sub-base are laid direct on the subgrade. On two new sections, near Regensburg CA 3) and near Rothenburg CA 7), the so-called...
Construction of airfield pavements with concrete
Larger aircraft, heavier lo~ds, in~reasing numbers of load repetitions, but e8pec~ally s~ngle wheel loads of about 33 tonnes have given rise to d~age which has similarly affected airfields all over th~ world. The damage is in part due to the sub-base be1ng too weak and to lack of shear transfer...
Concrete safety barriers: conditions of utilisation
The theme of safety for the vehicles on the road is very important and involves problems of several kinds. A system to limit the damages produced by the road accidents consists in placing at the edges of the road fixed and continuous obstacles which are called "safety barriers". In Italy,...
Concrete pavements without and with dowels
The deformation behaviour of a transverse joint, without and with dowel bars, under the passage of a wheel, as calculated with the aid of Westergaard's formulae /1/ is represented in fig. 1. This shows that when there are no dowel bars and no aggregate interlock across the crack (efficiency index...