Caltite Self-Compacting Concrete

Caltite Self-Compacting Concrete


Rehabilitating & Waterproofing the Structure

The basement of a building at an education facility was deteriorated by soil water which caused sever water leakage from the basement floor and walls. To rehabilitate the basement, a special “waterproof” concrete mix was required.

Caltite concrete is a waterproofed concrete which reduces capillary water absorption as well as reduces permeability to water under pressure. Such properties allow waterproof concrete to be used in water-resisting construction below ground in place of water-proofing membranes. The particular mix design has not been used before in Saudi Arabia.

Project Requirements:

  • Target strength: 40 MPa @ 28 days
  • High waterproofing properties: water absorption, according to BS 1881:122, less than 1%
  • W/cm ratio: 0.35-0.40
  • Wall jacketing, thickness around 15 cm

 

Challenges:

  • Concrete floors and walls should be impervious to stop any ground water ingress
  • Very thin reinforced sections with limited pouring points
  • Very difficult to vibrate and compact of the placed concrete, especially in the walls
  • Many openings, connections and pipes in the existing walls
  • Difficult to reach by a mobile pump inside the existing basements

 

Solutions:

  • Caltite (waterproofing admixture) was used in the mix design to meet the strict waterproofing requirements.
  • Self-compacting concrete (SCC) with a 700 mm flow was the solution for pouring the very thin wall section without vibrators.
  • The self-compacting concrete also acted as a self-leveling concrete for the basement floors to ensure easier and faster placing.
  • Extension pipeline systems were used to deliver concrete from the mobile pumps to the basement.