Case 2

Good Practices

Concrete

Ensure a good mix of dense concrete in order to improve durability. This has to be achieved at various stages in the process.

Design

• Specifying a dense concrete with minimum water-cement ratio.
• Ensure that the concrete mix is appropriate and to the specifications specified. Suitable grading of all suitable materials combined to provide the least amount of voids.
• Sufficient cover to reinforcement must be maintained.

Material

• Select appropriate concrete, reinforcement for concrete work.

Construction

• Ensure that the concrete mix is appropriate for construction and to the specifications specified. Mix concrete properly on site. Use a container, not a shovel, to measure each part of materials used in the mix. Add only enough water to obtain an even, workable mix.
• If the concrete is ready mix, it shall comply with SS 289.

• Reinforcements should be laid properly under supervision of consultant engineers and removal of rust and mill scale is important before embedment.
• They can be protected further by using the following methods:
  • use of non-metallic coatings such as epoxy coatings or cement based coatings
  • use of metallic coatings such as Zinc and Nickel
  • Cathodic protection
  • use of corrosion inhibitors
  • use of corrosion resistance reinforcement (eg. stainless steel)
• Ensure thorough compaction of the concrete during placement.

Quality Control

• Check for quality of concrete before placing. e.g. water cement ratio, slump test, etc.
• Check for correct concrete cover thickness.