The standard of serviceability of road pavements can be expressed in terms of safety for the user (skidding res is tance, riding quali ty). For highway managers a standard of structural serviceability is essential for optimizing the initial constructional expenditure and for predicting ~he time schedule for maintenance, strengthening or...
State of the art of concrete safety barriers
In 1976 the ~ew Jerey concrete safety barrier and the experience gained internationally with it was for the first time brought to the attention of interested persons in highway authorities, research and industry in the Federal Republic of Germany. Four years later, the first pilot projects were implemeneed in this...
Experiences with sand-cement stabilization in road construction
At Hamburg, sand-cement stabilization (SCS) conseructed by the central-mixed (stationary plant) method is successfully used for frose-protection courses. The requirements applicable to these courses, which as a rule are 15 em thick, are based on those for cementbound sub-bases as laid down in the TVT regulations: degree of compaction ~98%,...
New concrete curing compounds and their application to road construction in Austria
The curing compounds hitherto employed have not always been found satisfactory when applied to road concrete with superplasticizer, to concrete on small jobs, to concrete placed by slipforming and to cement-boundsurfacings. For this reason three new types of curing compound have been introduced, namely, compounds which - give good protection...
A continuously reinforced concrete pavement (0.35 m thick) for the steel mill Sidmar in Belgium
The project consists of the construction of a continuously reinforced steel slag concrete pavement (0.35 m thick) on a base course of slag sand-bound granular material (0.85 m thick). The road (area 8,000 m2, width 10 and 17 m) has to lenable the transportation of hot (800 0 C) steel...
Slab behaviour of plain undoweled concrete pavements
The behaviour of plain concrete slabs, belonging to pavements with no dowels through transversal Jo~nts, is described. The slab behaviour is observed by means of field instrumentation, measuring absolute deflections produced by environment variations (temperature and moisture), by support rigidity variations and by a controled axle load. Deformations are measured...
Use of residues from the incineration of domestic wastes and other residual matters mixed with cement in road construction
The incineration of household refuse in the Federal Republic of Germany yields up to about 3.5 million tonnes of residual waste per year. About 90% of this consists of grate ash and about 10% of fly-ash, the latter mostly being collected in electrostatic precipitators. The grate ash consists chiefly of...
Results of measurements on concrete roads
Besides theoretical work, investigations on specimens in the l~boratory and practical tests, in-situ measurements provide the means of assessing and further developing new concrete pavement systems. It emerges that, apart from the behaviour of a c?nc7e~e pavement at an early age (random cracking), s~gn4flcant changes (e.g., sinking, opening of joints....
Mix design and properties of lean concrete for sub-bases
The principal criteria applicable to the mix design and the properties of lean concrete are: - splitting tensile strength in the region of 1.7 MFa and compressive strength in the region of 15 MPa at 28 days; - good erosion resistance; - lowest possible modulus of deformation; - possibility of...
Retarders and their influence upon the properties of a cement stabilised soil
The engineering properties of a soil-cement mix are adversely influenced by any delay between mixing and compaction. This problem is more serious in hotter climates where the initial setting period is relatively short. As a consequence of this situation, the final product often fails to meet specification requirements. A laboratory...
Construction of airfield pavements with concrete
Concrete pavements have for years been successfully used in airfield construction. The relatively high weight of the landing gear of large aircraft requires pavement thicknesses which are considerably higher than those of concrete roads. The construction of airfield concréte pavements requires appropriate placing techniques. On account of the high loads...
Critical views on the procedure for and assessment of concreteroad conditions (Results of an investigation carried out on behalf of the Ministry of Transport
The resu l.cs of a research project are reported in ,which a method for the visual surveying of the condition of concreee roads was developed. In collaboration with three Federal German States, the road maintenance procedure hitherto applied was examined. The furcher investigation comprised the development of data recording sheets...