30 years of quality precast products


Infracast manufactures two types of culverts with a range of Span & Height:

  1. S-Class Portal Culverts
  2. SAR-class Portal culverts


Available in a range of span from 450mm – 3600mm, each size has a range of height from 300mm – 3000mm. For each span except 3600mm, the tallest length supplied is SPAN = HEIGHT. S-Class culverts have a range of strength from 200S, 175S, 150S, 100S & 75S.


Precast portal culverts are supplied in respect of their crushing load/strength as a combination of load cases involving vertical & horizontal knife edge test conducted under factory conditions. The Proof Load Test can be defined as a line load that a culvert should sustain without developing a crack of width exceeding 0.25mm over a length of 300mm continuously. An Ultimate Load Test is a failure load test to determine whether the culvert can sustain 25% more load without collapsing or failure.

There are 3 tests conducted on a Culvert to ascertain the requirements of SANS 986 are met, namely: deck bending moment, deck shear, and inner leg bending moment.


SAR portal culverts are manufactured for installations under railway track and designed to take account of train track, ballast and backfill load combinations. The fill height above culverts determines the classification of the culvert. The class are:

  1. 0-5m fill
  2. 5-10m fill

Special fill height can also be accommodated as per the customer’s specific design requirements.