Filter

Concrete Safety Barriers and Coming European Standards

Highways Members Only

For the year-long approved concrete safety barriers, produced of in-situ concrete or prefabricated units, the new EN 1317 part 1 will discribe the general criterions of the test methods in the future, and part 2 the performance classes and acceptance criteriOns. The opening of the European Market has consequences for...

Surface Characteristics of Two Recently Constructed Trunk Roads in the UK

Highways Members Only

In an effort to tackle road traffic noise, research into quieter road surfaces has included trials of a new type of concrete surfacing called exposed aggregate concrete, which has been used in a number of other European countries. Two trials of exposed aggregate concrete have been constructed in the UK;...

Vibration Absorbing Concrete Pavements

Highways Members Only

The evaluation and control of vibrations induced in the environment by the road traffic is a problem of increasing concern mainly in urban areas. Several solutions are under development to define pavement structures capable of absorbing traffic vibrations so to reduce the impact on the environment surrounding the road infrastructure....

Test-Methods on Road Concrete with a Very Porous Structure

Highways Members Only

Research is carried out in the Magnel Laboratory - Ghent University into the properties of road concrete with a very porous structure, enriched with polymer emulsions. The aim of the tests is to optimise the composition of the porous concrete. In this context, the choice of the type of polymer...

Recycling Cold-Milled Asphalt Concrete Materials as Cement Bounded Base

Highways Members Only

The authors present a synthesis of the results obtained on 3 test sections where cold-milled bituminous concrete has been recycled for the reconstruction of the stabilized base for medium trafficked roads. The inert skeleton for the base was made from 85% (by weight) milled material and 15% sand, this in...

Noise Absorbing Walls

Highways Members Only

The context resulting from the development of tfansportations and the requirements of a better accoustic confort. • Characteristics of the noise: sound speed; accoustic pressure; accoustic diagram; directiveness of the sound; accoustic spectrum. • Environment impact of the noise. Comparison of the railway and roadway noise. Most important factors that...

Test Sections of Noiseless Cement Concrete Pavements

Highways Members Only

Halfway through 1996, six different wearing courses were casted over a length of 3 km on the N255 Edingeri-Ninovc at Ilcrnc and Gaimaarden. 4 Different wearing courses each 4 cm thick, were casted on a continuously reinforced concrete pavement. In addition to the conventional wearing courses SMA 0/14 and ZOAB...

Requirements for the Application of Surface-Retarders in Whisper-Concrete Road-Projects

Highways Members Only

Although the quality of the surface-deactivator is very important, the surface-deactivator will only react to the quality of the concrete onto which the surfcedeactivator is applied to. Therefore the surfacedeactivator will not be able to compensate for segregations, unsuitable concrete mix-designs or mistakes in application, etc. It is always recommended...

Use of Calcium Aluminate Cement in High Strength Concrete for Fast Repair of Old Concrete Slabs

Highways Members Only

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...

High Performance and Rapid Setting Concrete for Airports Roads, the Experience of Madrid-Barajas Airport

Airports Members Only

This report details the reconstruction of 12,500 m 2 of 7.5*7.5*0.4m concrete slabs on the Madrid-Barajas airpoi't apron, using high performance and rapid setting concrete (HPRSC). HPRSC is an ideal concrete for this type of repairs, given that within six hours of placing the slab is able to bear its...

Whitetopping and Ultra-Thin Whitetopping – the US Experience

Highways Members Only

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...

Implementation of Ultra-Thin Whitetopping in Florida

Highways Members Only

In 1996, the Florida Department of Transportation (FDOT) started a research project to evaluate design, construction and performance of the ultra-thin whitetopping on asphalt pavements. Three UTW test tracks were constructed at the FDOT research facility in Gainesville, Florida. The design of the UTW test tracks included thicknesses ranging from...