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Experiences with a slipform paver equipped with a dowel placing device

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On the basis of experience gained on the Wildon road construction section it can be stated that slipforming is technically superior to conventional concrete placing. This applies more particularly to the better flexural strength of the top-course and bottom-course concrete in the pavement slab, the better evenness (riding quality), the...

Continuous quality control of high performance concretes for road – within the framework of site supervision – using a new field tested BASIC-MC programme

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Introduction and statement 'of problems: This paper closes the gap in concrete highway engineering technology by evaluating complex compactionphenomena and by deriving mathematical relationships between the concrete-technological, dynamic (thixotropic- plasticized) and physical parameters. It is based on the latest experience, e.g., including the construction of the concrete pavements of the...

Construction and performance of concrete pavements in Bavaria

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For economic and environmental reasons various motorways in Bavaria" have been provided with concrete pavements in recent years. In this form of construction the concrete slab and cement-bound sub-base are laid direct on the subgrade. On two new sections, near Regensburg CA 3) and near Rothenburg CA 7), the so-called...

Assessment of the evenness of cement concrete pavements and study of the means to achieve high quality evenness

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Pavement evenness is one of the characteristics that are most directly felt by the road user. It determines not only driving comfort and safety for obvious reasons, but also the dependability and operation costs of vehicles. Evenness is measured using longitudinal profile surveys produced by the A.P.L. (longitudinal profile analyzer)....

Joints in concrete roads – Aspects of construction and performance

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Increasing demands are bein~ made on joints in conérete roads by greater traffic 'voluines anld heavier loads. Most joints 'perform satisfactorily, yet a small proportion fail in service, resultinn in expensive remedial work. The paper reviews the main types of joints, and problems associated with their construction and performance. It...

Surface treatment of limestone concrete slab with the chipping technique

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Since 1980 the technique of pavement construction with thick concrete slabs has been applied on 100 km of the A.26 motorway (Calais - Reims) in northern France. The concrete employed is made with regional limestone aggregates. In order to counteract lowered skidding resistance due to wear of these materials, a...

Construction alternatives for drainage when reconstructing motorways

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Arrangements for surface and for the harmless di.scharee of saepaee water are dealt with. A differentiated analvsis of the long-term behaviour of the solutions adcp ced is g~ven, depending on the substantially different soils occuring as road foundation and subgrade. In connection with surface drainage the drainage arrangements at the...

Survey of drainage methods for concrete road pavements

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In the Federal Republic of Germany, as in other countr~ es, concrete road pavements have in recent years been affected by deteriorative damage which is attributable to Lhe presence of wa ter in the pavement. lnvestigations which the Federal lnstitutefor Highway Englneerlng (Bundesanstalt für Strassenwesen) started in 1981 aimed at...

Side drainage and sub-soil drainage layer operation and performance

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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

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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

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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

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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%,...