In the last few years at several airports cracking in the internals of concrete gutters has been detected. This was mainly observed, where large airfields (about 60 to 100 m in length) are located next to these drainage lines. In order to reveal the influences on this cracking both laboratory...
Precast and In-situ Concrete Barriers the Complete Safety Solution for Roadsides
The technology of in-situ concrete safety barriers has not really changed in the last two centuries. After an extensive development and crash-test program a new generation was created recently. This is a technical report on the right way to use in-situ concrete at today´s level of technology. In the central...
Fibremix Concrete for Pavements Experimental Search for Maximum Crack-Free Slab Length
Road constructions with fibremix concrete allow longer distances between joints, compared to unreinforced concrete pavements. In the absence of a dedicated design tool for fibremix concrete pavements, the search for a maximum crack-free slab length took place in several projects. Fibremix concrete has been used in parking areas near motorways,...
Uncertainty Management in Comparative Life-Cycle Assessment of Pavements
There is significant uncertainty and variation in the environmental life cycle assessment of pavements. Uncertainty and scenario variation should be sufficiently accounted in the comparative life cycle assessment in order to increase the confidence on decisions regarding the environmental implications of alternative pavement systems. In this paper we first present...
Experimental Short Continuously Reinforced Concrete Pavement Crack Pattern and Load Transfer Efficiency Across Cracks
As a proposed long-term pavement solution for bus stops and corridors in highly urbanized areas, four experimental short continuously reinforced concrete pavement (CRCP) sections with different percentages of longitudinal steel were built in São Paulo, Brazil. The pavement sections are only 50 meters long each, a short constructive length in...
A Framework for a New Protocol for Evaluating Concrete Curing Effectiveness
Excessive early early-age concrete surface moisture evaporation can be a source of key issues in the paving of concrete pavemen t, such as plastic shrinkage cracking and spalling related delamination; the use of liquid membrane membrane-forming curing compounds is one of the most prevalent methods to protect hydrating concrete surfaces...
Recyclable High Volume Fly Ash Pavement Concrete Using Limestone Aggregate
Fly-ash is a pozzolanic material, so it can contribute to various properties, such as strength development at mature age. The strength development at early age, however, is significantly slow and may negatively affect traffic service. Early strength may be improved when limestone filler is mixed in fly-ash concrete. In addition,...
Relevant Interactions for Alkali-Silica-Reactions in Concrete Pavements
In the last few years cracking in concrete pavements often is attributed to alkali-silica-reaction (ASR). Although this is a very important aspect other impacts such as traffic loads and restraint stresses due to thermal and hygral effects may not be neglected. In many cases interactions between various causes can become...
Air Void Formation in the Laboratory and in Practice
As a result of a short mixing time excess air-entraining agent (AEA) is added during the production of air-entrained concrete to achieve the required air content. In this case, the fresh concrete contains AEA that has not been fully activated. If there is a subsequent input of mixing energy, the...
Guidelines for Concrete Roundabouts in the Netherlands
Due to the durability advantages of concrete pavements, the application of concrete for roundabouts is gaining more and more popularity among commissioning authorities. In the Netherlands it is estimated that there are over 3,000 roundabouts. The market share of concrete is still growing. Concrete roundabouts can only be durable when...
Effect of Curling Behavior on Surface Smoothness of Continuously Reinforced Concrete Pavement
The curling behavior of the continuously reinforced concrete pavement (CRCP) under environmental loads was analyzed by measuring vertical displacements at a number of different longitudinal and transverse locations, and the relationship between the surface smoothness and curling behavior was investigated. Two different crack spacings were selected and at each discrete...
The Rehabilitation of the Underpass Bleicherweg in Zürich
In Zurich the underpass Bleicherweg had to be maintained. An important part of the job was the pavement. The civil engineering department of the city of Zurich decided that the original asphalt pavement had to be replaced with a concrete pavement. The base of this decision, minimize possible water vapor...