Two test sections were constructed with a base course of porous concrete under the emergency lane of a motorway. This base composed of new aggregates or recycled aggregates, has the strength of a cement treated base and the function both of bearing capacity and drainage. Mixed in Plant and placed...
Effects of Classified Fly Ash on Improving the Compactability of Roller Compacted Concrete for Pavements
Roller compacted concrete (RCC) pavements are expected to be an economic and rational concrete pvPmAnt system that will become increasingly popular in Japan. The maximum thickness of a RCC slab completed in one layer is limited to 25 cm because of limitations in the compactability of the concrete and the...
Longterm Effects of Environmental Aggressiveness on Steel Fiber Reinforced Concrete For Road Construction
Steel-fiber-reinforced concrete (SFRC) has found several interesting applications in the field of road pavement and structure maintenance operations (overlays and bridge decks, prestressed beams, expansion joints). One possible drawback, however, is fiber corrosion, especially across cracks, with resulting disconnections between adjacent slabs and deterioration of reinforced concrete. The present paper...
Changes of Ultrasonic Characteristics in Concrete Road Surfaces
To determine the concrete strength of a road surface the authors of this paper have used an ultrasonic method. In this method, longitudinal waves are directed to a concrete slab by means of transducers applied to the upper surface of the slab. If the propagation time and the distance between...
Application of Newly Developed Prestressed Concrete Pavement Technology in Japanese Airports
Many researches on prestressed concrete (PC) pavements have been conducted. The applicability of a class Ill PC slab, in which cracking at the bottom of the slab is permitted, was confirmed for airport pavements. A new type of PC precast slab pavement with new jointing systems was developed. A new...
Skid Resistance of Exposed Aggrcgate Concrete
From 1990 to 1992 exposed aggregate concrete was used for the construction of 14 sections of Austrian motorways. This technology offers a noise reduction and a higher level of skid resistance. In order to evaluate the skid resistance of these surfaces in comparison to others, measurements were carried out in...
Project Numerical Models and Comparison with Experimental Results
The present paper illustrates the experience of ITALCEMENTI S.p.A. and C.T.G. S.p.A. (former ITALCEMENTI INGEGNERIA S.p.A.) in designing CRCPs. During 1991-1 992 a slip road was built between the MONSELICE cement plant (Padua) and the state road "S.S. 10 Padana Inferiore" in order to divert heavy vehicle traffic driving to...
First Application of a Concrete Inlay on a Bitumen Paved Motorway in Belgium
The motorway A7, also called the "Motorway of Wallonia", was opened to traffic in December 1970. In the vicinity of Mons this motorway carries a very high volume of heavy traffic, which is still increasing. The right-hand (slow) lane is subject to severe rutting, which has affected the deeper layers....
Concrete Made of Building Demolition Waste
In the field of research on secondary materials, an experimental study on the re-use of building demolition waste has been conducted. These materials will be used in Italy, further to decree-laws and regulations, drawn in compliance with the rules of the Community Law 1 9 w93h, ich has already been...
Performance of Concrete Pavement Drainage Systems in Spain
At present Spain has 1600 km of concrete pavements (two lane carriageways). The particular conditions of the climate and the heavy traffic make it necessary to use different measures to avoid joint faulting and voids under the slabs such as dowelled joints, non-erodible base courses, sometimes complemented by joint sealing...
Roller Compacted Concrete Pavements for Port Yards
Roller compacted concrete pavements (RCCP) are favourable for port yards. To develop the design, both the bearing capai-ity and the load transfer efficiency at the joints were studied. An experimental pavement with two different RCCP structures was built: namely, one that follows the ordinary design method for port yards consisting...
Some Characteristics of Polypropylene Fiber Reinforced Concrete
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...