A number of research projects relating to the cementbound sub-base (CBSB) are currently in progress in the Federal Republic of Germany. Their object is to develop an optimized technological approach with a view to further improvement and even greater economy in the use of this well proven form of construction....
Development of the technological concept for roadbases made of hydraulic bound granular materials in the Federal Republic of Germany
Realization of agricultural roads in concrete in Belgium
The construction of concrete agricultural roads continues to increase in Belgium; latest statistical data show that public autorities still rely on this type of pavement. A new design method was recently proposed and published by the Ministry for the Walloon Area; it is based on simple concepts and its application...
Criteria for the technical choice of priority sections to be reinstated on roads with concrete pavements
Concrete pavements have been used to a wide extent in France on the st.rategic motorway network of the Paris area and on development trunk roads such as the Paris- Lyons. Due to the age of such road pavements, some of which are more than 25 years old, and the large...
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%,...
Joint design for concrete pavement on cement stabilized base at Zürich airport
On the concrete pavements of the runways 14 - 32 and 16 - 34, built in 1975 and 1976, cracks developed along the tongue-and-groove longitudinal joints. Investigations into the service conditions of the joints showed that they were overstressed unde r extreme loads and that damage to them could be...
Influence of Thermal Gradiente on Non-Destructive Evaluation of Concrete Pavements
The non-destructive evaluation of a concrete pavement must account for the temperature warping condition of the slab at the test time. In fact the thermal gradients induced in the slab by the daily temperature variations cause the temperature warping of the slab and this affects the value of the maximum...
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...
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...
Critical assessment of various construction techniques
The long-term behaviour of various types of road pavement construction can be estimated or prognosticated from a methodical assessment of the condition of the roads and the associated data collection. Prognoses can be made not only with regard to technical cri teria, but also with regard to overall cost trends...
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....
Effect of cement-bound sub-bases on cracking
Cement-bound sub-bases (CaSBs) are constructed ~ithout joints. During and after hardening, cracks may be formed in consequence of drying and/or cooling, even if the sub-base has noc yet been subjected co any traffic load. It would be desirable to have no cracks or only very fine ones (capable of eransmieting...
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...