Reflective Cracking on Concrete Pavements with Cement Treated Sub-Base

Conf-paper-iscr

One concrete pavement just built was showing some located transverse cracking. In order to evaluate the cracking cause, longitudinal displacements were measured in some cracks and transverse joints. Results obtained showed that concrete cracking was reflected from cement treated base cracks, and allowed to verify that such phenomena happened in...

Performance of Crack & Seat and Saw & Seal Overlays

Conf-paper-iscr

Maintenance problems in asphalt concrete overlays over portland cement concrete pavements may result from reflection cracking at the location of working joints and cracks in the underlying slab. Two methods of reflection crack control which have been used by many agencies in the United States within the past ten years...

The Use of Roller Compacted Concrete Pavements in Argentina

Conf-paper-iscr

The use of roller compacted concrete in high-way works started in Argentina in 1986 through a programme developed by the Instituto del Cemento Portland Argentino, ICPA (Argentine Portland Cement Institute). Several sections were designed and constructed in different areas of the country, using traditional laboratory tests, mix proportioning methods and...

Concrete Structures Made of One Piece Lean Concrete Slabs French Experiments and Pavement Design – Future Developments

Conf-paper-iscr

France has an extended experience in hydraulic binder treated materials: in semi-rigid structures, in cement concrete thick slabs, in lean concrete for concrete pavement subbase layers. It has permit-ted to establish a new and very competitive struc-ture: the lean concrete thick slab on a drainingcourse with or without tranverse joints.A...

Highway Liquid Sealants a South African Perspective

Conf-paper-iscr

This paper presents aspects of liquid sealant installation and behaviour in joints in concrete roads under South African con-ditions. It covers joint preparation, installations techniques,quality control and field testing. A description of the generictypes of liquid sealants is given as well as behaviour charac-teristics obtained from laboratory tests which included:...

Improvement of the Road Surface Evenness of a Concrete Pavement by Grinding

Conf-paper-iscr

Diamond grinding of a new concrete pavement surface produced an improvement on the road sur-face evenness which was evaluated in almost twounits in the International Roughness Index scale(mikm). This improvement was achieved mainlybecause of the removal ofroad irregularities withshort and medium wavelengths (0,5m

Resistance of Concrete Safety Barriers and Concrete Road Against the Scaling Action of Deicing Salts

Conf-paper-iscr

The paper presents a synthesis of results related to the construc-tion of concrete safety barriers and of a study about the treat-ment of roads in which the strength against deicing salts wastoo low.A survey of the 13 concrete safety barriers after 3 wintersshows that there is a rather good relation...

Appropriate Technology Concrete Pavement Trials in Zimbabwe

Conf-paper-iscr

In 1985 four trial sections of two-lane concrete pavement were laid in Zimbabwe. The purpose was to provide a data base for the preparation of appropriate design and maintenance specifications, suitable for the conditions found over a large part of Africa, namely, good subgrades, moderate rainfall, large temperature variations, low...

Experiences in Non-Destrucfive Testing by Impulse Radar and Impedance Methods in the Evaluation of Concrete High-Ways

Conf-paper-iscr

The background to the two methods is given; together with their application to concrete pavements. Three case histories are presented where concrete highways have been tested by these techniques in the United Kingdom, some sections having asphalt overlays. The relative merits and disadvantages of the two methods are discussed in...

Thin Continuously Reinforced Concrete and Steel Fffire Reinforced Concrete Overlays – Performance Affer Three to Eight Years

Conf-paper-iscr

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

Conf-paper-iscr

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...

The Effect of Heavy Loads on the Stress Distribution at the Surface of a Crc Pavement

Conf-paper-iscr

A continuosly reinforced concrete pavement has been laid in 1984 within the steel mill Sidmar near the city of Ghent in Belgium. This paper deals with the tests performed in 1987 on the pavement and the analysis of the results. A French device, called "Ovalimètre", made it possible to measure...