Petrography

Petrography is an important component of forensic engineering and provides insight into the underlying causes of performance failures for a variety of materials including concrete, brick, block, and stone masonry, mortar, wood and glass. Investigations of concrete failures often pose specific challenges because of variations in mix design, quality of construction, and in-place service conditions.

 

APPROACH

In a concrete investigation, petrographic analysis allows the engineer to understand the roles of quality and environment, their relative significance in causing the critical failure, and their impact on developing appropriate repairs. Our petrography team evaluates factors that affect performance and long-term durability of concrete, including cement content, air content,

water/cement ratio, placement and finishing practices, and sampling and testing errors.

 

To ensure the quality and efficiency of our petrographic analyses, SGH has a fully-equipped laboratory that utilizes stereo microscopes (10X to 100X), a transmitted light polarizing microscope (10X to 1,000X), an ultraviolet, reflected light microscope (10X to 50X), and cutting and lapping equipment to create flat, polished surfaces. The microscopy lab also includes a computer-assisted, linear-traverse instrument for conducting hardened air-void analyses.

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