Special Concrete for Sulphur Pit Construction

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.