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...
Concrete Recycling in Belgian Road Construction – Applications in Cement Bound Road Bases and Surfacings
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...
New from Old – Recycling Concrete Pavements
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...
Elastomer Profiles for Concrete Roads
Since 1985 more and more elastomer prnfiles MA iiced for longitudinal and transverse joints of German highways to get a watertight filler between the concrete slabs. Specially designed highway profiles are compression seals that can be installed even under wet and cold weather conditions. They can follow very large joint...
Recycling of Concrete for the Reconstruction of the Concrete Pavement of the Motorway Vienna – Salzburg
From 1991 to 1993 60 km of carriageway were reconstructed on the motorway Salzburg-Vienna, re-using the old concrete pavement 100% on the work-site. The fine material (0/4) that resulted when crushing the old pavement was added to the old granular subbase which without would have been too coarse-grained to be...
Experiences with the Treatment of some Defects of a Concrete Pavement during Construction
The aim of this paper is to discuss some defects of the concrete pavement during the construction of the second northern expressway project in Taiwan. The possible reasons of and techniques for repairing these defects are studied in the paper. The defects discussed include the cracks in the lean concrete...
Reconstruction of Concrete Pavements Using Rubblized Bases
Reconstruction of concrete pavements can be performed by fracturing the existing concrete slabs into small pieces in situ and then placing a leveling course and overlay. The fractured slabs provide a firm base for the new pavement. The technique is increasingly used for the reconstruction of concrete pavements where the...
Mix Design for Concrete Pavements Durability Options Based on the New European and Italian Standards
The provisions of the European Prestandard ENV 206 "Concrete - Performance, Production, Placing and Compliance Criteria" place the accent on the qualitative requirements (physical, chemical and mechanical ones) of a durable road concrete. The theoretical life of a rigid road pavement obviously r1.pends on the design and the quality control...
Application of Cement to Stabilize Used Materials in Hydraulic Bounded Subbases
In the last few years the interest for preventive environment measures has increased. That is the reason for stimulating the re-use of waste materials as a means of recycling. With the aim of stimulating the recycling of waste materials, the interest in using cement to stabilize different materials increased. This...
Reuse of Alkali Damaged Road Concrete in Cement Bound Road Bases
Aggregates were obtained from an alkali-silica damaged concrete road slab aggregates and used for road base concrete with different kinds of cement (low alkali cement, high alkali cement). After analysing the samples produced with these mixes, which were exposed for up to one year to different hardening conditions, no alkali-silika...
Roadway Pavements of Recycled Concrete
In Switzerland deposits of gravel are growing scarce. For this and ecological reasons an effort is being made to recycle material, i.e. material produced by roadway demolition -instead of being dumpedshould be re-used in a way to achieve the highest possible quality. This means orderly reconstruction and separation of the...
Fine-Grained (Sand) Concrete for the Construction of Cement Concrete Road and Airfield Pavements
The problem of using fine-grained (sand) concrete instead of the "classic one in the construction of road and airfield pavements is analysed. In sand concrete the coarse aggregate, crushed stone or gravel, are substituted by natural sand or a blend of natural sand and screenings 0.5 (10) mm. The use...