Pyrite Investigation

Pyrite Investigation

The presence of pyrite-bearing aggregate in the granular base of a building can affect the condition and durability of the slab-on-grade, foundations, and building structure.  CRA's team of building science specialists and technical experts provide a full range of sampling and testing to evaluate the swelling potential of pyrite-bearing aggregate.

The sulphate products generated during the oxidation of pyrite can damage the underside of the slab and weaken the concrete. This phenomena (sulphatation) may cause cracking, delamination, reduction in compressive strengths and floor capacity, efflorescence, swelling in the slab's surface, or lateral displacement of foundations.

Investigation and analyses are conducted according to the NQ-2560-500 protocol, with analysis of materials completed by our CTA-accredited in-house laboratory.

Services

• Visual evaluations of slab-on-grade and foundations
• Coring and retrieval of subgrade materials
• Analysis of subgrade by
  • Petrographic count (ASTM C 295)
  • Petrographic number (BNQ 2560-900)
  • IPPG rating and heaving potential (CTQ-M 200)
  • Chemical analysis for sulphur, aluminum oxide, and sulphates
  • Microscopic petrographic examination
  • Durability and MgSO4 testing (according to standard BNQ 2560-450)
  • Abrasion measurement by Micro-Deval device (according to standard BNQ 2560-070)
• Repair specifications and repair cost estimates
• Tender documents/bid revision
• Project management
• Quality control and testing
• Expert testimony and litigation support