Construction

The surfaces of concrete carriageways are subject to continuous wear due to the action of traffic and also to that of frost and the application of de-icing salts. The deteriorative damage affecting the concrete can range from mere surface wear by abrasion to loosening oi the structure of the material...

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...

The construction of concrete pavements is associated with various requirements to be fulfilled, e.g.: full-width construction stripwise construction, but extending over the full width ) e.g., construction of new cancrete roads addition of traffic lanes to existing carriageways ) e.g., on roads in use by traffic renewal of traffic lanes...

Even though a bonded overlay has the advanta~es such as lower cose and fewer problems in matching adjacent facilities, ic has not been used widely in Japan. The reason is that bond characteristics in concrete overlays have not been revealed and insufficient bond in con~entional techniques has caused some problems...

The conventional form of construction for permanent way, as first conceived about ISO years ago, adopted the ballast bed for supporting the railway track from what at that time was the most economical road building method, namely, macadam. By the same token, a p:esent-day innovative form of permanent way construt~...

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...

The technique of con5tructin~ thick concrete overlays is at present being greatly developed in Belgium. Three periods are to be distinguished in overlay construction in this country: 1960 to 1969: experimental phase in which 210.000 m2 of overlay was constructed; 1970 to 1977: the second phase, in which the results...

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...

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...

In Austria bonded overlays only 35 mm thick are made using a superplasticized concrete with a wie - ratio of 0.35 . The overlay has to be moist-cured. For thicknesses of only 20 mm a special latex addition is used. For good bond the concrete is brushed vigorously with a...

A survey of European concrete road construction is presented on the occasion of the fifth International Symposium on Concrete Roads. The Synoptic Table 1986 c~nta~ns in tabul~r form the principal data and guidel~ nes for the des~gn and construction of motorways and other roads of con~rete in 15 European countries....

The report deals with technical and economic improvements resultiRg from the use of a concrete paving train in the construction of concrete roads. The following parameters are investigated: number of trucks needed for the transport of concrete depending on the capacity of the mixing ~lantt the progress rate of the...