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~...
New developments in the construction of railway track bases without ballast
Design of concrete pavements
Together with the increasing demand for concrete pavements in the Netherlands, the need for a technically and economically justified method of pavement design arose. On the basis of the present knowledge on the stress and deformation behaviour of concrete under static and repeated loading, a method of concrete pavemen~ design...
Construction of farm roads with cement-bound sub-bases used as pavement
Many minor roads are constructed with a cement-bound sub-base not provided with a surfacing. Two such experimental se~tions of road are described in this paper. One of these sections comprises a cement-bound crushed stone sub-base (shell limestone 0 - 45 mm size). It was constructed with a binder content of...
Assessment of the performance of the structural properties of concrete pavements by means of the falling mass deflectometer
The paper describes the survey and assessment of the structural properties of concrete pavements with the aid of in-situ and non-destructiveloading tests performed with the Dynatest 8000 falling-weight deflectometer (FWD). The following parameters for carriageway slabs with joints are considered: (I) modulus of elasticity of the concrete slabs; (2) modulus...
Development of the technological concept for roadbases made of hydraulic bound granular materials in the Federal Republic of Germany
A number of research projects relating to the cementbound sub-base (CBSB) are currently in progress in the Federal Republic of Germany. Their object is to develop an optimized technological approach with a view to further improvement and even greater economy in the use of this well proven form of construction....
Realization of agricultural roads in concrete in Belgium
The construction of concrete agricultural roads continues to increase in Belgium; latest statistical data show that public autorities still rely on this type of pavement. A new design method was recently proposed and published by the Ministry for the Walloon Area; it is based on simple concepts and its application...
Criteria for the technical choice of priority sections to be reinstated on roads with concrete pavements
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...
Experiences with sand-cement stabilization in road construction
At Hamburg, sand-cement stabilization (SCS) conseructed by the central-mixed (stationary plant) method is successfully used for frose-protection courses. The requirements applicable to these courses, which as a rule are 15 em thick, are based on those for cementbound sub-bases as laid down in the TVT regulations: degree of compaction ~98%,...
Joint design for concrete pavement on cement stabilized base at Zürich airport
On the concrete pavements of the runways 14 - 32 and 16 - 34, built in 1975 and 1976, cracks developed along the tongue-and-groove longitudinal joints. Investigations into the service conditions of the joints showed that they were overstressed unde r extreme loads and that damage to them could be...
Influence of Thermal Gradiente on Non-Destructive Evaluation of Concrete Pavements
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...
Mix design and properties of lean concrete for sub-bases
The principal criteria applicable to the mix design and the properties of lean concrete are: - splitting tensile strength in the region of 1.7 MFa and compressive strength in the region of 15 MPa at 28 days; - good erosion resistance; - lowest possible modulus of deformation; - possibility of...
A continuously reinforced concrete pavement (0.35 m thick) for the steel mill Sidmar in Belgium
The project consists of the construction of a continuously reinforced steel slag concrete pavement (0.35 m thick) on a base course of slag sand-bound granular material (0.85 m thick). The road (area 8,000 m2, width 10 and 17 m) has to lenable the transportation of hot (800 0 C) steel...