Effect of cement-bound sub-bases on cracking

Conf-paper-iscr

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...

Theoretical study of technical and economic improvements resulting from the use of equipment train in concrete pavement construction

Conf-paper-iscr

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...

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

Conf-paper-iscr

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

Conf-paper-iscr

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

Conf-paper-iscr

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...

Structural design of concrete pavements

Conf-paper-iscr

Under present economic conditions the use of bitumen is being reduced as much as possible. For more than twenty years the application of semi-rigid pavements has revealed the drawbacks but also the advantages of such structures. The chief advantage is their low cost, which can be further reduced if the...

Side drainage and sub-soil drainage layer operation and performance

Conf-paper-iscr

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...

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

Conf-paper-iscr

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

Conf-paper-iscr

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

Conf-paper-iscr

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

Conf-paper-iscr

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...

Fatigue experiments for the design of plain concrete pavements

Conf-paper-iscr

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...