Factors Affecting the Formation of Air Voids in Road Concrete

Highways Members Only

A greatly increased air void content in the hardened concrete has been found in recent years in some contract sections of concrete pavement. Investigations were carried out at the Research Institute of the Cement Industry on road concretes in order to determine the reason for this excessively high content. The...

Influence of Moisture on the Deformation (Warping and Curling) of Concrete Road Pavements Consisting of One or Two Layers with and without Recycled Aggregate

Highways Members Only

Depending on the environmental conditions during casting and hardening, actual temperature and moisture gradients in concrete pavement induce strains. These strains lead to deflections of the slabs or, when restrained, to stresses and in some cases, mainly in combination with traffic loads, to cracks. Concrete with recycled concrete aggregate (RC-Concrete)...

Alkali-Silica Reaction Prevention by Lithium Salts

Highways Members Only

After the exploration of damages caused by alkali-silica reaction (ASR) on highway bridges in Turkey recently, the usage of reactive aggregate on highway construction was prohibited. However, this does not seem to be the proper solution, because natural aggregate leads to an increase in workability of concrete due to its...

The Acoustical Properties of Optimised Exposed Aggregate Concrete in the Netherlands

Highways Members Only

About nine years ago, the Dutch Association of the Netherlands Cement industry (VNC) initiated indicative noise measurements on three new types of concrete roads. It was shown that exposed aggregate had a potential for further optimising. The Dutch Information and Technology Centre for Transport and Infrastructure (CROW) initiated in 1996...

Roller Compacted Concrete

Highways Members Only

Roller concrete has been adopted from dam-building technology, where it is used as a rapidly constructed and durable solid concrete. In road construction, roller compacted concrete is predominantly used in foundations, as a supporting layer. For surfacing or as a layer of surfacing. Some applications in Belgium are discussed. This...

Investigation of Maintenance Needs For In-Service Concrete Pavements

Highways Members Only

Given the large number of concrete pavements that have performed well over time and lived up to prior expectations, as well as the knowledge that is now available regarding the reasons for failure in certain concrete constructions, it should be possible to carry out an evaluation of these pavement types....

Test Sections of Rigid and Flexible Pavements

Highways Members Only

The number of heavy vehicles in the Swedish road network is continuing to grow, and more rigid types of pavements are being used to withstand the loads. During the 1980s only asphalt pavements were used in Sweden and damage occurred on many roads with large traffic volumes. The Swedish National...

Road Roughness and Its Effects on the Infrastructure Caused by Dynamic Wheel Loads

Highways Members Only

The intention of this paper is to shed light on the interaction between road roughness and the resulting road damage caused by static and dynamic wheel forces. For this purpose several trucks have been mathematically modeled as multi-body systems in great detail. The models are based on actual data of...

From the Road To the Railway Urban Transportation Trackdim Transposition of a Calculation Method

Highways, Trackslabs Members Only

Alstom who is a major company in the turnkey railways construction activity including railways track construction, developed an adaptation of roads and highways calculation modelization based on concrete fatigue resistance under traffic loads to for railways tracks calculation purpose. Roads and highways have a long and rich experience and data...

The Importance of High Range Water-Reducers in Concrete Quality

Highways Members Only

This paper is based on a research project, which has covered the importance of high range water-reducers (HRWR) on properties and consequently on quality of concrete. More precisely deals with the influence of six HRWR of an amount of twelve which were tested. They have been prepared concrete mixes with...

Prefabricated Concrete in the Service of Urban Development

Highways Members Only

The needs of road managers cover a number of sometimes conflicting aspects, which have to be reconciled. These relate to the durability of the works, their flexibility of use and reuse, their ease of maintenance and of course their long term cost. They also relate to the safety of the...

High Performance Concrete Effects of Curing Conditions

Highways Members Only

The use of high performance concrete (HPC) is becoming more popular in the United States. Many State Departments of Transportation are replacing conventional concrete especially with HPC bridge decks. Despite the growing popularity of the material, little is known on the effect of the available curing methods on the mechanical...