A very favourable result emerges from the assessment of the soundness of structural arrangements adopted and developed over the past ten years (3rd International Conference at Purdue, April (985). After briefly reviewing this positive achievement resulting from closely concerted action of road managers, practical engineers and researchers, the authors more...
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...
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...
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%,...
Development of the technological concept for roadbases made of hydraulic bound granular materials in the Federal Republic of Germany
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....
Design of concrete pavements
Together with the increasing demand for concrete pavements in the Netherlands, the need for a technically and economically justified method of pavement design arose. On the basis of the present knowledge on the stress and deformation behaviour of concrete under static and repeated loading, a method of concrete pavemen~ design...
Ten years of hydraulic concrete pavement of the Mediterranean 75 highway
The highway Tarragona-Valencia-Alicante, 375 km along che Spanish easccoasc, has 240 km of concrete pavement. It is being used, in sections, since June 1974. Due co the similar climate and geology of California (U.S.A.) and che Spanish Levante, in the initial design of 1972 Californian technology was mainly used. The...
Improved jointed concrete pavement designs through field observations
This paper will provide specific recommenda~ions for the improvemen~ of jointed concre~e pavement design practice. Tbe recommendations will be based upon findings from a major nationwide research project recen~ly completed in the USA concerning field observations of pavement performance. A concre~e pavement performance database was established and extensive data collected...
Erosion of concrete pavement sub-bases
A special session of the 65th annual meeting of the Transportation Research Board in Washington, in January 1986, brought together some 50 practitioners and research workers on the theme "Erosion of sub-bases; stepping of slabs and pumping of concrete pavements"; ~he presentation of 3 U.S. papers and two French ones...
Commnon loadbearing effect of concrete pavement and cementbound sub-base
The combined load bearing action of the concrete pavement and the cement-bound sub-base (CRSB) has a favourable effect on the long-cerm behaviour of che road structure in the case of unreinforced concrete road slab construction wichout expansion joints. as has proved effective in Germany: - Because of che roughness of...
Microcracked semi-rigid structures
Under present economic conditions the use of bitumen is being reduced as much as possible. For more than twenty years the application of semi-rigid pavements has revealed the drawbacks but also the advantages of such structures. The chief advantage is their low cost, which can be further reduced if the...
New guidelines for the standardization of pavement structures 1986 edition (RStO 1986) – Comparative study at European level
The new standardization guidelines RStO 86 contain rules for the surfacing of roads and other trafficked areas with bituminous, concrete or block pavements, for fully cement-bound pavements as well as for cycle tracks and footpaths. Six pavement construction classes are distinguished, depending on traffic loading. For determining the construction class,...