Customer
Joint venture QBC (Vinci/CCC/Hochtief). Designer COWI
Case
Bridge Qatar Bahrain Causeway is to be built between the two Arab states of Qatar and Bahrain. The link between the two countries would be approximately 40 km (25 mi) in length, and would be a dual two-lane road. The link is expected to consist of a number of bridges combined with roads constructed on causeways and will be a natural extension of the King Fahd Causeway that connects Bahrain and Saudi Arabia, thus linking the entire region.
The middle east is a harsh environment for concrete, especially areas near the Gulf. Therefore early age damages to the concrete like cracking and loss of concrete quality due to insufficient curing need to be prevented.
Measures to prevent these kind of damages are available, but have a large impact on construction sequences and can cause serious delays if not accounted for. Therefore SGS INTRON was asked to assess the risk of early age damages to the concrete structures and to provide recommendations to avoid these damages. Detailed plans will be developed at a later stage in the project.
Some of the activities of SGS INTRON were:
- Evaluation of mix design and concrete properties
- Analysis of the structures to be built and selection of most critical components
- Finite element analysis to predict temperature, stress and strength development
- Development of measures (mitigation techniques) to reduce the risk of early age damages
- Finite element analysis to calculate the impact of the measurements
- Recommendation of possible mitigation measures and actions to be taken
Solution
Some of the structures analyzed have a high risk of early age cracking. These cracks arise due to the heat of hydration in concrete and restrained deformations. For these structures several techniques were proposed to lower the risks. The impact on the risk was calculated and quantified. The impact of these techniques on construction sequence and duration was quantified. For the curing criteria were proposed. Based on these criteria curing regimes were calculated for several structural elements These calculations were performed with highly specialized finite element techniques co-developed by SGS INTRON.
Year
2009