The purpose of this paper is to bring to the attention of the highway community in Portugal, a methodology that allows the construction of bridge decks with Portland Cement surfaces without the need to use bituminous surface layers. This paper will present construction methods, cost benefit analysis, some of the...
Why Should Bituminous Layers Be Used Over Portland Cement Bridge Decks
Whitetopping and Ultra-Thin Whitetopping – the US Experience
Concrete overlays of existing asphalt pavement, referred to as "whitetopping," is one of the most rapidly emerging technologies for rehabilitating pavements in the U.S. Although its use can be traced back to 1918, conventional (or classical), whitetopping became routinely used in the mid-1970's with use significantly increasing in the 1980's...
Possibilities of Quality Determination of Concrete Surface Layers
Possibilities of applying methods of surface absorption, mercury intrusion porosimetry, pull-off strength tests and thermal analysis in the assessment of the state of the surface layer of a concrete airport runway are given. The results of the tests of properties of differently deteriorated surface layers of concrete in an airport...
Method to Establish the Porosity – Depth Distribution of Porous Concrete Pavements Using Cylindrical 100 Cml Cores Samples
The paper deals with a low cost method to establish the porosity - depth distribution in porous concrete pavement using cylindrical 100cm cores samples. The outcome is a graph representing the porosity in function of the depth below the surface. The method is non destructive with regard to the core...
Analysis of the Response of Concrete Pavement Slabs Jointed by Dowel Bars
The present paper aims to contribute to the study of the structural response of concrete slabs jointed by dowel bars in pavements. As is known, a common construction technique of pavements is this one that uses concrete slabs interconnected each other in both directions by equidistant dowel steel bars. A...
Use of Calcium Aluminate Cement in High Strength Concrete for Fast Repair of Old Concrete Slabs
The oxides present in the chemical compositioii of calcium aluminate cement, especially monocalciiim aluminates. is what gives the concrete manufactured with this type of cement its slow setting, quick hardening properties. The products generated during hydration of anhydrous phases in calcium aluminate cement. will depend on ambient conditions at the...
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...
First Experimental Application of Deactivated Coloured Concrete in Belgian Road Construction
Deactivated coloured concrete is characterized mainly by two factors: its colouring and its surface treatment. Colouring is achieved by using preferable coloured aggregates and admixing the mortar with a dye. The surface treatment consists of chemical aggregate exposure. A first major experiment in Belgium combining coloured concrete and chemical aggregate...
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...
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...
Recycling Concrete Pavements in Motorway Construction
Concrete, which has withstood all the loads on heavily used roads for many decades, can be used again as a concrete aggegrate in road pavement construction after undergoing appropriate treatment. The example of four pavement batches prepared by 2 different companies in 1992 and 1993 on the A27 motorway m...
Development of a Roller Compacted Concrete Pavement Reinforced with Continuous Steel Bars
A roller compacted concrete pavement (RCCP) reinforced with continuous steel bars was recently developed at the New Tokyo International Airport. The construction is fast and the effectiveness of load transfer at cracked sections of the continuously reinforced concrete pavement is high. This RCCP was built in two layers. Steel bars...