Materials

For some years now the interest for the environment together with economic reasons, improvements of crushing plants and the definition of acceptance criteria have led in Belgium to an increased use of crushed concrete aggregate and sand in cement bound bases. Recent official circulars and tender specifications allow for the...

In many countries rullw cumpactod concrete (RCC) proved to be a success as a construction method for highly stressed industrial floors, for concrete pavements, subbases for concrete pavements and asphalt surfaces. Since 1993 the Research, Development and Consulting Department of tho Heidelberger Zement AG is attended with a research project...

About 50% (150 km) nf the ennerete pavement on the motorway Al Vienna-Salzburg are older than 30 years and need reconstruction: The recycling method developed in 1 989/90 is based on the principle of making new from old. The old concrete pavement is used as a quarry and provides the...

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...

Precracking techniques are used for materials treated with hydraulic binders in order to restrict the effect of shrinkage cracks on the pavement performance. After developing a precracking technique for port platform stwctures in 1984, Via france recently received and developed a new technique for road pavements. This technique applies to...

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...

Session Paper Indexes, Opening Addresses, General Reports, Oral Contributions and Closings from the 6th International Symposium on Concrete Roads 1990 Madrid Spain

Aggregates from crushed road concrete were tried in 7 test sections, and 84 samples from some lOcrushing plants were :ested in the laboratory. lt has been shown that aggregates suitable for re-use in sub-Jases or road bases can be produced not only in fixed plants butalso by small mobile crushers,...

A stretch of the slip-road between the Al and A2 (Fiano tomano-S. Casareo) has been made of PCP (polyfunctional .omposite pavement). The system is "composite" owing to the rresence of several layers: mix cemented to cement binder, :ontinuous reinforcement concrete slab and bituminous layer; 'polyfunctional" owing to the diverse functions...

Roller-compacted concrete (ReC) offers a solution to the vast number of good quality lowvolume roads which will have to be provided in the near future to accommodate South Africa's rapidly expanding rural road needs. The research effort presented in this paper involved a laboratory study and the construction and accelerated...

Recyclingmaterials and industrial by-products are suitable for building purposes if the constructions made of them adequately withstand all loads occuring during the scheduled period of utilization and if they do not affect the environment unac-ceptably. Therefore the evaluation of recycling-and secondary materials must cover both the cons-tructional and the ecological...

In areas with a low bearing capacity of the soil it is very hard nd expensive to manage and maintain the road system. In eneral the common pavement structures are not able to resist uring its lifetime the deformation of the subsoil caused by the eavy weight of pavement structures....