In the sixties and seventies it used to be the traditional way to build paved country roads in full width in rural road construction. Economical consciousness, agricultural production zones -in the context of developing better economical systems-forced us to change our views. A very natural path is a wheel-track path...
Long-Time Observations of Contracfion Joint Opening in Concrete Pavements Measurement and Evaluation
Long-time measurements of contraction joint opening were performed during a 25-year period for several pavement systems [concrete full depth construction, concrete pavement on a temperature insulated, cement treated (CTS) and bituminous subbase]. The data obtained were analyzed and the mean opening of the joints, the standard deviation, the coefficient of...
Thin Continuously Reinforced Concrete and Steel Fffire Reinforced Concrete Overlays – Performance Affer Three to Eight Years
Since 1982 experimental sections of thin overlays have been constructed for an amount of 171.000 m'. Eight of these sections are made of 10 to 12 cm thick steel fibre reinforced concrete, six of them on a bituminous underlayer and two on old concrete pavement. Four other sections should verify...
Properties of Roller Compacted and Vibrated Concrete at Early Ages Evaluation Through Ultrasonic Energy Measurements
Measurements of the energy of ultrasonic pulses as a means of establishing the relationship between the structure of material md its properties, have bcen studied during a long period of .ime in the Torroja Institute. Energy quantification of the pulse does consider all the characteristics of wave and materials. This...
New Design Method and Fatigue Analysis of Rigid Pavements with Variable Thickness
A new process for the structural plate analysis has been presented that is based on the condition of stationarity of total complementary energy (equilibrium model) instead than on the condition of the stationarity of the total potential energy (con-gruence model) as usually done. Each of the two processes, asregards to...
Some Theoretical and Practical Aspects of the Use of Fly Ash in Lean Concrete
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...
Optimization of Surface Characteristics of Cement Concrete Roads
The surface properties of a road pavement must fulfill a long list of requirements. Recently this list has been extended to include acoustic properties. Roughness is characterized by micro-, macro- and megatexture. The results of measurement of skid resistance and road-tire noise are discussed. Possibilities for further optimization of the...
The Use of Seismic Tests to Assess the Properties of Portland Cement Concrete During Curing
«In situ» measurements of surface wavevelocityon two prototype concrete slabs indicate that seismic measurements offer a reliable alternative to con-ventional penetration resistance and cylinder com-pression tests for determining the stiffness of Port-land cement concrete during curing. The surfacewave velocity was determined using a nondestruc-tiveand nonintrusive technique called the SpectralAnalysis of...
The Use of Steel Fibre Reinforced Concrete in Heavy Duty Port Pavements
Recent years have witnessed a considerable growth in importance of heavy duty pavements, mainly because of several major pavement failures in ports leading to serious problems. A recent development took place in the concrete technology and has considerably increased the cost effectiveness and performance of concrete heavy duty pavements making...
The Asturias Motorway Balance of Its First 15 Years Under Traffic
The Asturias motorway, called «y» -asturiana, links the three most important cities in Asturias. It has 43 km of continuously reinforced concrete pavement and was built during 1974and 1975.The behaviour of the motorway up to now has been very good in spite of the rainy weather and the unfavourable geology....
Problems of the Reconstruction of Motorways in the Gdr
The 1860 kilometre GDR motorway network was mainly built in concrete slab construction before 1945. Its overall reconstruction is vital. In the course of reconstruction work a number of different paving variants were put into practice. The covering of unbound and nearly impermeable bases needed the drainage of the intermediate...
RCC Applications in Low-Volume Roads in Spain
The first known applications of RCC pavements in low-volume roads in Spain took place around 1969-1970. They included pavements located on housing developments, urban streets and rural roads. These applications have been increasing until now, when the technique is used in different parts of Spain and in other countries (Norway,...