Materials

Session Paper Indexes, Opening Addresses, General Reports, Oral Contributions and Closings from the 6th International Symposium on Concrete Roads 1990 Madrid Spain

An accelerated road-wear simulator employed by Norcem for experimental testing of abrasion resistance of highway concrete pavements subjected to heavy traffic by studded tyres was set up at Slemmestad, Norway in 1985. By increasing concrete strength from 50 up to 120 MPa, the abrasion was reduced by roughly 60-70 %....

The new concept of the urban fabric is taking on extension and is testifying increasingly to the fact that in our cities the street is not a road. Cement concrete designs have been staying abreast of these developments and architectural concrete is just one of the significant outgrowths of these...

Heavy use of the pavements caused by traffic, cli-mate and winter service requires a highly resistantconcrete with high flexural strength. Correspon-ding requirements on road concrete are laid downin «Additional Technical Instructions for Cons-tructing Concrete Pavements» (ZTV Beton), partlyalso requirements on some concrete basicmaterials.All materials used for construction of concretepavements have...

To determine the concrete strength in road surface the authors have applied an ultrasonic method. In this method ultrasonic transducers are imposed to the upper surface of the pavement slab. The distance between the transducers is constant. Next propagation time of longitudinal ultrasonic wave is measured. The time of propagation...

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...

The Long-Term Pavement Performance (LTPP) research program, a component of the Strategic Highway Research Program (SHRP), was launched in 1987 as a $50 million effort to collect field observations of both in-service and new, specially constructed test sections throughout North America. This paper deals primarily with the pavement distress evaluation...

Over the past few years, interest in the uses and applications of porous cement concrete for pave-ments has been growing. Its position in pavementconstruction has developed to such an extent thatit iscurrently used in places of greater importance(from shoulders to sub-bases, and even surfaces).This paper is part of the experience...

This paper proposes a theoretically sound method of modeling the reliability function of pavement sections, using a statistical procedure that can correctly consider test sections that have not yet reached failure. Consistent and accurate reliability estimates were obtained applying this method to a continuously reinforced concrete pavements (CRCP) data base...

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:...

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...

This paper reports on the first phase of a test programme which compares the performance of concrete ground slabs with (a) no reinforcement, (b) steel fabric reinforcement, (c) steel fibre reinforcement and (d) polypropylene fibre reinforcement. The slabs were 3.0m square, 0.15 and 0.13 m deep and subjected to a...