Effect of the distribution of air entrained in superplasticized and high workability concrete for traffic areas

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For obtaining a high degree of resistance to the action of frost and de-icing salts on concrete, it is essential to have an adequate content of air-filled micropores adjusted to the amount of fine-grained mortar in the mix. With QOI1ventional road concrete, correctly made, it can be presumed that if...

Criteria for the technical choice of priority sections to be reinstated on roads with concrete pavements

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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...

Use of cement-bound industrial wastes and recycled materials in earthworks and road construction

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For environmental reasons, it is becoming increasingly difficult and eherefore expensive to find fresh sites for wasee disposal. Investigations have shown that coal fly-ash, refuse incinerator grate ash, demolished road asphalt and concrete rubble can, when suicably treated with cement, be economically reused for road construction, for which purpose they...

Fatigue experiments for the design of plain concrete pavements

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In the design of plain (unrelonforced) concrete pavements the influences of traffic and temperature, among others, are taken 1.nto account. These sue j ect, the pavements to load var1.a1:.l.onBse.cause the traffl.c comprises vehicles W1.th widely differing wheel loads, the loading pattern due to it is very erratl.c: the frequency dnd...

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...

Design and construction of continuously reinforced concrete composite pavement for the A63 South Docks Road Hull

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The paper describes the approach adopted for the design and construction of a continuously reinforced concrete road base (CRCB) pavement for a major trunk road proect in the north-east region of the United Kingdom. The trunk road, known as the South Docks Road, is currently under construction and programmed for...

Construction of airfield pavements with concrete

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Larger aircraft, heavier lo~ds, in~reasing numbers of load repetitions, but e8pec~ally s~ngle wheel loads of about 33 tonnes have given rise to d~age which has similarly affected airfields all over th~ world. The damage is in part due to the sub-base be1ng too weak and to lack of shear transfer...

Influence of Thermal Gradiente on Non-Destructive Evaluation of Concrete Pavements

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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...

Use of new road materials (industrial wastes) in mixes for sub-bases

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The replacement of traditional aggregates (limestone) by crushed blastfurnace slag or LD steelmaking slag in lean concrete and in cement-stabilized hardcore was investigated. The effect of adding fly-ash to mixes of the conventional type was also studied. For mixes of equal composition (in parts by volume) and equal grading (by...

Concrete pavements without and with dowels

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The deformation behaviour of a transverse joint, without and with dowel bars, under the passage of a wheel, as calculated with the aid of Westergaard's formulae /1/ is represented in fig. 1. This shows that when there are no dowel bars and no aggregate interlock across the crack (efficiency index...

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...

Road concrete with superplasticizers

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Road concrete made with superplasticizers has successfully been used for about ten years now. Its special features with regard to mix composition and method of placing were reported in detail at the London symposium in 1982. This method of construction is increasingly being applied in Austria: - For the maintenance...