Highways

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...

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...

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...

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...

For the time being the exposed aggregate technique is the cheapest way of building a rigid pavement with a surface that is noise reducing, skid resistant and durable. The technique requires the use of specially adapted payers, very good-natured retarders and a very efficient curing. Special combinations of surface retarders...

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...

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....

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...

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 (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...

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...

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...