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...
The Reuse of Old Pitch Containing Asphalt in Cement Bound Base Courses Depending on the Level of Harmful Substances
Use of Porous Bases for the Drainage of Concrete Pavements in the USA
In the United States, many States are using free draining porous bases under new portland cement concrete pavements. These porous bases are intended to remove infiltrated surface water, which cannot be prevented from entering the pavement structure. The porous bases used in the United States have coefficients of permeability ranging...
Performance of Roller Compacted Concrete Pavements in Spain
Roller compacted concrete (RCC) began to be used in Spain in 1984 on roads bearing heavy and medium traffic. Up to now more than 250 km of RCC pavements have been constructed. A significant portion is subjected to the combined effect of heavy traffic and servere temperature gradients. Joints are...
Upgrading of Porphyry 04 Crushed Stone Sand By Stabilization with Cement
One way of upgrading crushed stone sand is to add cement, for the purpose of using it in a foundation layer. The authors report on their experience with stabilization by means of cement and with the use of the material in the foundation of a motorway work site. The previous...
Wear Resistant and Noise Reducing Concrete for Road Pavements
Rutting, depending on the wear of studded tyres, is a problem in the Skandinavian couritiis. Concrete pavements have a good wear resistance. In Ai.ustria they have recently developed a low noise concrete with small aggregate size and exposed aggregate. Earlier experiences have shown that the wear resistance of concrete is...
European Concrete Pavement Trial Project in the USA
The State of Michigan in the United States of America constructed a trial project that incorporated highway pavement design features from Germany and Austria. The project considered a 25.4 cm unreinforced concrete pavement, over a 15.2 cm lean concrete base, over a 40.6 cm granular frost layer. The concrete pavement...
Concrete Pavements in Heavy Rain Areas
The difficulty to build roads in heavy rain areas is illustrated through the reconstruction of the road going from Pasto (the capital of the Department of Nariño) to the port town of Tumaco, in the vely South of Colombia at the Pacific Cost and the border with Ecuador. Despite this...
Compressive Stresses in Concrete Pavements and Related Maintenance Problems
The M20 motorway between Junctions 3 and 5 near Maidstone (UK) is an unreinforced pavement with joint spacings of 5m and 6m, comprising warping joints with contraction joints every 30m. The pavement was constructed at the beginning of the 1 970s. A contract for maintenance between Junctions 4 and 5...
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...
Concrete Block Pavement Structure with Porous Concrete Base
Heavily trafficked concrete block pavements (CBP) require a proper designed cement treated base, which however i.g. offer only a low water permeability. Hence water may accumulate in the beddinq layer and under unfavourable climatic conditions frost heavings and deteriorations can occur. This can be prevented by a base course of...
Experimental Study on the Correlation between the Mix Factor and the Compactability of Concrete for Roller Compacted Concrete Pavements
This study was carried out to examine the correlation between roller compacted pavement concrete mixes and the compactability with surface vibrator. Two factors are significant for the consistency of the concrete: the sand/cement ratio of the mortar component by weight and the coarse aggregate/ mortar ratio by volume. The most...
Elastomer Profiles for Concrete Roads
Since 1985 more and more elastomer prnfiles MA iiced for longitudinal and transverse joints of German highways to get a watertight filler between the concrete slabs. Specially designed highway profiles are compression seals that can be installed even under wet and cold weather conditions. They can follow very large joint...