Why we choose to use concrete spacers over those made of plastic, granite stone…?

Plastic spacers

Plastic spacers do not bond well with concrete. When the concrete is poured into the form, a small gap is created between it and the plastic. Plastic has a coefficient of thermal expansion and contraction 10 to 15 times that of concrete, and when subjected to temperature variations, the plastic continues to expand and contract at that higher coefficient. At high temperatures, plastic can even melt. The result is a separation between the spacers and the poured concrete, creating a free passage for corrosive agents to reach the steel reinforcement from the exterior of the concrete product. This will cause the steel – and eventually the concrete – to corrode.

If steam curing is applied to the concrete, the heat in the curing process causes the plastic to expand while the concrete is relatively fresh and weak. After reaching the maximum curing temperature and volume expansion of the plastic, the temperature is held at this level until the concrete reaches the desired strength. After curing, the subsequent lower temperatures cause the plastic to contract, and a gap remains at the interface between the plastic and concrete.

Plastic spacer are also subject to corrosion when they come into contact with chlorides and chemicals, where concrete has a much higher resistance.

Granite stone

At the construction site, it is often found that using 10x20mm granite stone to support for the steel frame of foundation is technically wrong, because the 10 × 20 granite stone can only be positioned temporarily for reinforced beams, when we walk or when the concrete slammed onto the reinforcement, the 10 × 20 stone lost its position and the reinforcement fell to the coffa, with no reinforced concrete (also known as steel), or concrete little guard.

Ngoc Lam Sai Gon Concrete spacers

Concrete spacers and bar supports are made of the same material as the poured concrete, so thermal expansion and contraction are equal. And because they are the same material, the concrete and spacers will bond. No gaps!

Concrete spacers help maintain material integrity and uniformity of the concrete, and provide a cover over the reinforcement that protects against corrosion.

Ngoc Lam Sai Gon is producing best strength of  concrete spacers, multi size from 15mm – 120mm.

Product characteristics: 

  • Fabricate with various height based on demand
  • Ensure the structural design of the steel frame
  • High compression strength
  •  Dimension and quality are stable
  • Prevent reinforcement steel from corrosion
  • Slow the melting of steel when burnt
  • Restrictions floor cracking, sagging floors
  • Increased waterproofing because homogeneous substance raw concrete floors.