Petrography as an essential complementary method in forensic assessment of concrete deterioration: Two case studies

The second case deals with pre-fabricated foundation piles that cracked upon pile-driving. The pile-driving contractor was blamed for the damage, allegedly from too much driving energy in combination with a worn-out wooden baffle. While the compressive strength of the concrete was normal, the tensile strength was found to be less than half of the expected value. Thin section petrography revealed poor adhesion of aggregate to the surrounding paste, confirming field observations. This could be attributed to “liquefaction and water expulsion” at an early stage of production when the piles still were under the care of the manufacturer.