Olympus BX51-P Polarising Petrographic Microscope

TRSC sub-contracts petrographic analysis to NATA-accredited materials laboratories that operate the Olympus BX51-P (or equivalent research-grade polarising microscope) on extracted concrete cores from TRSC investigations. The petrographic report is requested specifically when the diagnostic question requires identification of a deterioration mechanism that cannot be answered by direct testing alone — typical scenarios include suspected alkali-silica reaction (ASR) where reactive aggregate must be identified and confirmed; suspected delayed ettringite formation (DEF) where late-age expansion is a candidate explanation for cracking; carbonation-depth mapping where the carbonation front geometry must be quantified for residual-life estimation; and aggregate identification on heritage assets where the original material specification must be matched for compatible repair material. TRSC engineering reviews the petrographer's report and integrates the findings into the structural assessment — the petrographer identifies the material mechanism, TRSC translates that into the structural-engineering implication and remediation specification. Recent deployment includes selected core extractions from Marina Mirage marine concrete investigation (petrographic confirmation of chloride-induced corrosion mechanism + aggregate characterisation) and Victory Hotel heritage masonry investigation (mortar petrography to characterise original lime-mortar composition for compatible repair specification). The petrographic deliverable is typically a 10-15 page laboratory report with annotated thin-section micrographs at the magnifications relevant to the diagnostic question, and TRSC's investigation report extracts the petrographer's diagnostic conclusion into the engineering-implications section, with the full petrographer report retained as an appendix for the asset owner's own records and for any subsequent regulatory or insurance review — particularly important on alkali-silica reaction and delayed ettringite formation diagnoses where the petrographic evidence underpins the entire remediation strategy.