A wide experimental campaign was carried out on concretes with the addition of polypropylene fibers. This way it was possible to obtain useful information on the morphological structure, on the trend in time of compressive strength, splitting tensile strength and impact strength, and on the influence on these trends of...
Air Entraining Agents in Road Concretes and Characterization of the Air Void System in the Fresh Concrete
Various air-entraining agents were investigated for their physicochemical characteristics and for their foaming power. Correlations were found between this power and the parameters characteristic of entrained air. These parameters were determined on the fresh concrete using the DBT "Air Void Analyser". Air-entrained concretes have a water absorption very similar to...
Slab Thickness Design of Heavy Industrial Concrete Pavements
The design of concrete pavements for industrial facilities (truck or container terminals, industrial storage, harbours) has been based either on design catalogues or charts This paper introduces a numerical solution, based on the theory of elasticity expressed in form of series. The reason is that such pavements carry very heavy...
Surface Characteristics and Driving Comfort on two Swedish Concrete Roads
In Sweden there is an increased interest in the performance based specifications of concrete roads, such as wearing resistance, friction and noice. Recently two concrete roads have been constructed with the special intention to improve the surface characteristics. Both roads were constructed with concrete that is resistant to wear and...
Restraint Stresses in Young Concrete Pavements
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...