Design

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...

Requirements for concretes in colder environments are stricter than those normally requested for standard commercial concretes. Therefore, a concrete produced with (i) high quality ingredients, (ii) a water/cement ratio of 0.35 to 0.40 by mass, (iii) 3.0 to 6.0 percent entrained air, (iv) an adequate maturity, i.e. when the compressive...

Spain can boast of having a very large concrete pavement area, amounting to more than 90 percent in over 35 civil airfields and 5 military air bases. Technical details, construction methods and performance of these pavements are analysed, together with their evolution in the latest projects which have started in...

Washed or fine brushed concrete was introduced in the Netherlands, replacing rough brushed concrete, to reduce the road noice. In many cases the minimum friction coefficient required was not reached. However, measurements carried out some months later showed an improvement of the results. To investigate if this improvement of the...

The turnkey construction method can be very beneficial to an employer both during the bidding process and during construction. A turnkey road construction project was selected for the first time in Germany as the construction method for the A15 motorway between Cottbus-West and Forst. In order to alleviate backups within...

Road concrete in the thirties did not have a particularly high strength, but it grew over the years. Strength tests on cores, taken last year, show that the strength -compressive as well as the more important splitting tensile- of the old section and also of almost all new ones is...

Between 1982 aiid 1989, 8 thin overlay test sections were constructed with a total surface area of 129.000 m2 . The relevant research project is carried out with a view to the necessary future renovation of part of the Belgium road network. All sections were built with 10 to 12...

Heavily trafficked concrete block pavements (CBP) require a proper designed cement treated base, which however i.g. offer only a low water permeability. Hence water may accumulate in the beddinq layer and under unfavourable climatic conditions frost heavings and deteriorations can occur. This can be prevented by a base course of...

The use of CD 40-A cement eliminates the classical procedures of measuring plastifying and air entraining additives at the preparation on site of the road concrete. The article presents the main characteristics of CD 40-A and the results of laboratory tests carried out to establish the influence of this type...

Many researches on prestressed concrete (PC) pavements have been conducted. The applicability of a class Ill PC slab, in which cracking at the bottom of the slab is permitted, was confirmed for airport pavements. A new type of PC precast slab pavement with new jointing systems was developed. A new...

The latest version of the Austrian specifications for concrete pavements include paving between fixed forms and slipforrn paving, super plasticized concrete, recycled concrete and noise reducing concrete surfaces. This paper describes exposed aggregate surfaces, the requirements for concrete pavements and the materials used to make them.

At present there are still many hundreds of kilometres of concrete motorways in the former East Germany which were constructed in the thirties. The phenomenon is not the fact that now, especially after the last winter, a lot of them have reached a critical condition, but that until today all...