Under adversè conditions, the restraint stresses of young concrete pavements can cause the forma-tion of random cracks. In order to determine theparameters which influence the formation of thesestresses a full-scale experiment including sixdifferent test sections was performed. The experi-ment showsthe greatinfluenceof climaticconditionsin the days after placing the concrete. The analy-sis...
Cement Grouted Macadam
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.
Road Marking on Concrete Problems and Solutions
R.oadpaint containing a dissolving agent and hot applied ther-noplastic marking materials are most commonly used for roadnarking in the Netherlands. The only marking materials al-lowed on Dutch motorways are those that have proven theirsuitability in laboratory research and experimental sections on:he road. During a period of 25 years no concrete...
The Brite Project on the Freeze/Thaw Durability of Concrete Block Paving
The prime objective of this programme is to develop an ac-zelerated freeze/thaw performance test that relates reliably tofield performance.Samples of 40 experimental block mixes have been placed onone or more of 5 exposure sites. Data from meteorologicalstations on these sites are being used to model the relationshipbetween ambient conditions and...
Nature Related Constructions in Rural Districts Wheel-Track Paving with Concrete
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...