Conventional concrete safety barriers of the New Jersey type are frequently used in Belgium. At the end of 1993 more than 1600 km had been placed. Slightly higher precast safety barriers connected by a Swedish system have been successfully used especially to separate the traffic during reconstruction works of a...
New Developments in Concrete Safety Barriers – Variants on the New Jersey Profile
Accelerated Wear Testing of High Strength Concrete in Norway
To give guidelines for the mix design on high performance concrete with high wear resistance, and to study wear of high strength concrete, the Norwegian cement producer NORCEM operates a test rig specially developed for this purpose. The tests show concrete to give 2-3 times the wear resistance of asphalt....
Developments for the Exposed Aggregate Technique in Austria
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...
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....
The Reuse of Old Pitch Containing Asphalt in Cement Bound Base Courses Depending on the Level of Harmful Substances
Large quantities of old asphalt containing varying admixtures of tar/pitch are produced during the renewal of asphalt roads. These pitches contain environmentally relevant substances such as pnlyr.yr.lic aromatic hydrocarbons (PAHs) and phenols which must not be allowed to leach out into the ground water. The intention is to bind the...
Slip Formed MaIa Slotted Gutter
"MAIA" is a slotted driveable gutter used for the drainage of motorways and airports. T.S.S. adapted the SATUJO slotted gutter method to be realized on a slipform paver. The new concept is based on the insertion of an air inflated reusable flexible tube on a slipform paver which enables the...
New Standards in the Construction of Aircraft Movement Areas
Airport runways and other aircraft movement areas are among today's most important infrastructure elements. The paper gives an introduction to general aspects of design and construction of concrete airport pavements, emphasizing the advantages of the two-course "wet on wet" placement technique. The above mentioned aspects are illustrated by the description...
Noice Reducing Exposed Aggregate Surfaces – Experience and Recommendations
In 1990 a technique for building pavements with a noice reducing concrete surface was developed in Austria. The top layer contains aggretate with 8 mm maximum size. The surface is sprayed with a retarder and brushed the next day to expose the aggregate. This technique has been used on 120...
Flexible Concrete Pavements
The strength of flexible pavements is more or less at the limit of design, and only minor improvements in allowable contact pressure can be expected. Major increases in vehicle weight on flexible pavements is only possible by increasing the number of axles or by increasing any extra contact area (larger...
Laboratory Tests on Thin Bonded Overlays
The "technique of thin bonded overlays" has been applied to restore damaged concrete pavement surfaces. In this article results from laboratory tests concerning different combinations of repair mortars and several support concretes are piesciuted and discussed. Bond strength of the overlay to the supporting concrete has been assessed by means...
Stabilization of Contaminated Soils
The elution behaviour of acid and alkaline soils, contaminated with diesel oil, PER and mercury salt, of different grading curves (sandy loam to loam-free fine gravel), was examined both before and after stabilization with cement. After cement stabilization, all heavily contaminated soils (eluate class Ill) yielded an eluate that corresponded...