Construction

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...

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...

Industrial by-products have long been used in French road construction. Experience gained over the last twenty years with che extensive use of by-product gravel-sand stabilized with hydraulic binders as a sub-base material, as well as the results of highway engineering practice in neighbouring countries like Germany and Belgi~prompted the LPC...

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...

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...

In che paper, results are presented of laboratory research and applications in practice of concrete and masonry waste as aggregates for concrete. In a thorough study the amounts, composicion and relevant properties of the waste were investigated. Based on the results of tests in the laboratory and of full scale,...

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...

This paper will summarize results from a major research project on the repair of jointed concrete pavements in the USA. The study approach involved: (I) a comprehensive evaluation of current and new alternate methods of joint/crack repairs, (2) selection of the most promising techniques, (3) the development of design and...

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...

In a Spanish road in the main network that joins Zaragoza with Huesca, a 9 km long by~pass is being built, in order to supress two railway grade crossings and improve the location. The structural section consists in 15 em of lean concrete and 25 cm of pavement concrete. By...

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...