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HeidelbergCement in the United Kingdom

Trenchblock® Tongue & Groove / Hi-Strength Trenchblock® Tongue & Groove


Thermalite® Trenchblock® is a tried and tested, economical alternative to the construction of cavity walls with concrete infill, engineering bricks or heavy aggregate blocks for foundations.

Also available as Hi-Strength Trenchblocks® where strengths of 7.3N/mm² or 8.7N/mm² (10.4N/mm² equivalent) is required.

  • For use in soils of up to Design Sulfate Class DS 4
  • Available with tongue and groove joints and handholds
  • Improves thermal performance
Working dimensions
Face dimensions (mm) 440 x 215, 440 x 140*

Thicknesses and weights
Block thicknesses and weights at equilibrium density (for 440 x 215mm)
Thickness (mm)    255  275  300  355 
Trenchblock weight (kg)  14.9  16.1  17.5  20.8
Trenchblock 7.3N/mm² weight (kg)  18.1  19.6  21.3  25.3 
Trenchblock 8.7N/mm² weight (kg) 19.1 20.6 22.5 26.6

Block thicknesses and weights at equilibrium density (for 440 x 140mm)
Thickness (mm)    255  275  300  355 
Trenchblock weight (kg)  9.7 10.5  11.4  13.5
Trenchblock 7.3N/mm² weight (kg)  11.8  12.7  13.9  16.4 
Trenchblock 8.7N/mm² weight (kg) 12.5 13.4 14.7 17.3

Properties
Mean compressive strength not less than 3.6N/mm² (7.3N/mm²: Hi-Strength)

Designed thermal conductivity below ground (λ) 0.23W/mK (0.31W/mK: Hi-Strength)

Specified gross dry density 600kg/m³ (730kg/m³: Hi-Strength)

*Not available with tongue and groove joints.
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