Materials

This paper reports on the first phase of a test programme which compares the performance of concrete ground slabs with (a) no reinforcement, (b) steel fabric reinforcement, (c) steel fibre reinforcement and (d) polypropylene fibre reinforcement. The slabs were 3.0m square, 0.15 and 0.13 m deep and subjected to a...

Researchers and Technicians have ascertained that the use of ppropriate substitution materials in cement stabilizations and nixtures during the construction of road-base, sub-base and oundation layers allows to simultaneously fulfill technical-tructural, economical and environmental-ecological require-nents,~s an alternative by-product, Urban Solid Waste Ashes and:lags have been tested in a laboratory in...

During the last decades the use of Roller Compac-ted Concrete for pavements has increased worldwide. A concrete pavement of significant higherquality than typical Roller Compacted Concretehas been developed at Aalborg Portland. The con-creteisplaced and fullycompacted with an asphaltpaver, mounted with a heavy high-compactionscreed. No rollers have to be used. In...

The background to the two methods is given; together with their application to concrete pavements. Three case histories are presented where concrete highways have been tested by these techniques in the United Kingdom, some sections having asphalt overlays. The relative merits and disadvantages of the two methods are discussed in...

Cementgrouted macadam (CM) is a 150-200 mm thick baselayer of macadam, 32-65 mm, which is stabilized to full homogeneity with a cement-slurry composed by cement, sand, flyash, air-entrainer, a superplasticizer and water. The cement-slurry is spread out by a especially equipped caterpillar-tracked asphalt-paver.

The object of this articleisto evaluate the influence of materials used in the construction of rigid pavements, and of the method of placing the con-crete on the final pavement quality.Using the results of laboratory tests and experi-ments taken from the available literature, the ut-most attention must be paid to the...

lIn Norway, most every car is equipped with tires having small steel studs to improve the friction between the tire and road during the winter season. These studded tires have an enormous wearing effect on ordinary asphalt pavement.

Until a few years ago, interest in the incorporation of fly ash into lean concrete was rather limited. A study conducted in the laboratory has demonstrated some of the advantages of the technique and shown that the optimum dosage is of the order of5 %. In Belgium, mixtures of this...

Although the Belgian standards provide for quality control of idrnixtures for cement concrete, it is interesting to complement his information by a more thorough chemical identification. this makes it possible to increase the economic advantages vhich result from their use. nfrared spectrographic investigation, which enables the ategory of basic chemical...

Generally due to an unsufficient vibration, the concrete around the construction joints may contain cavities, especially under the reinforcement. When very hot weather conditions prevail, these deficiencies may cause important deteriorations, possibly with mere fragmentation of the concrete around the joint. As there are over 5.000 construction joints on the...

When treated with lime, wet cohesive soils granulate and be-ome more workable, thus allowing easier subsequent incor-oration of cement.'he effects of pregranulation with lime on various aspects ofement stabilization were investigated: compaction. CBR bear-19 capacity, strength values, durability, the effects of differentariables such as density and moulding moisture content. Theitter...

To ensure that concrete has a high resistance to freezing and thawing it must contain small air voids which are produced by an air-entraining agent and which must be present in sufficient quantities to match the amount of fine mortar. The limits for the air content of unset concrete and...