Recyclingmaterials and industrial by-products are suitable for building purposes if the constructions made of them adequately withstand all loads occuring during the scheduled period of utilization and if they do not affect the environment unac-ceptably. Therefore the evaluation of recycling-and secondary materials must cover both the cons-tructional and the ecological...
Cements For Concrete Pavements Mixed Cement Or Type V with Fly Ash
In Spain the development of cement, specially for concrete pavements, has been based on making use of fly ash in cement production. Such a development was achieved after studying the characteristics of the available fly ash and the respective experiencies. The results led to a widespread use of this type...
Concrete Setis a Functional and Rational Technique
The use of concrete setts in France has been growing for a decade, especially on urban roads. This technique, inspired by stone setts, but also by such precast concrete products as kerbs and gutters, very quickly generated needs: for design methods, for standardization of the product, for rules for use....
Reflective Cracking on Concrete Pavements with Cement Treated Sub-Base
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
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
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
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
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
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
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
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
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...