Project Requirements:
Requirements of Mix ingredients and Proportions:
- Ternary mix with the use of GGBFS and Silica fume
- Non-calcareous aggregates
- Maximum W/CM ration = 0.36
Requirement of Fresh Concrete Properties: Self-competing concrete with the following properties:
- Slump Flow: 650±65 mm at 2 hours
- Static segregation index: 0 to 3.8% according to ASTM C1610
- J-ring test: Passing Ability < 25 mm according to ASTM C1621
Requirements of Hardened Concrete Properties:
- High strength concrete: 60Mpa at 56 days with a safety margin not less than 8 MPa
- RCP charge less than 1000 coulombs at 56 days according to ASTM C1202.
- Water Absorption less than 1.2% according to BS 1881-122
Challenges:
- Developing of self-compacting concrete which meets with the project requirements for far-distance sites. Track mixer takes more than 75 minutes to reach the project site.
- Self-competing concrete with a high pump-ability property which it has to facilitate pumping of the concrete without blockage, segregation or major loss in slump flow.
- Producing of a concrete with challengeable durability requirements.
- Use of a high quality non-calcareous aggregate: this type of aggregate is not available in eastern region of Saudi Arabia. It should be transported from western region to the locations of batching plants with a consistent highly quality to ensure the quality of the finished project and a constant supply to ensure on-time delivery.
Solutions:
- Product development plan has been developed for the proper selection of mix ingredient, mix proportion and qualified suppliers. Plan has been executed through a co-operation of Technical, R&D and operation departments.
- A programme of extensive lab and plant trials have been excused to develop a concrete mix that meets with all projects requirements.
- Working closely with a highly qualified admixture supplier for developing a brand new admixture that facilities high pumpability properties, enhancing viscosity characteristics and allow a longer workability retention.
- Working with highly qualified suppliers of non- calcareous aggregate to ensure consistent and highly quality aggregates to be delivered on time to SRMCC factories in Jubail and Hafouf cities.
- Finial Plant trails have been conducted a one day before the actual pouring day in order to simulate the actual pouring and confirm the conformance with all challengeable requirements of fresh concrete including pumpability requirements.
- Hardened concrete samples have been sent to a third party lab for ensure meeting with the requirements of durability.