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 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...

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...

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...

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...

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...

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...

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

During hardening concrete pavements do not have a uniform distribution of temperature throughout the thickness. The calculation of tem-perature stresses has to start from the differencebetween the zero-stress-temperature and the actualtemperature. Itisadvantageous if (for example dueto wet-curing) the zero-stress-temperature is lowerat the top than in the middle of the slab....

In order to design a cement bound mixture for use in base/sub-base pavement layers, it isusually re-quired to obtain a certain minimun strength value.Ifonly one type of binder isused, the problem hasonly one restriction and one variable, so, one onlysolution. However, if more binders are added tothe mixture, asit happens...

The use of concrete safety barriers is currently increasing considerably. The area of use, limited for a long time to urban or suburban carriageways, has now spread to the whole of the road network. The appearance of sites longer than 10km had led companies to work in a different manner,...

A series of tests have been carried out to figure out the in-fluence of deviation of the dowels on concrete paving slabdowels with respect to slab movements through shrinking andthermal variations.The stresses produced in the slabs for various deviations withrespect to the theoretical position and according to the systemchosen to...