Beneath the Surface: A Petrographer’s Look at Type IL Cement:

As Type IL Portland-limestone cement has become increasingly common in concrete construction, engineers, architects, contractors, and material suppliers have encountered questions regarding how this cement affects   concrete performance, durability, and observed distress. Petrographic examination provides a unique opportunity to look beyond strength test results and evaluate what is occurring within the concrete at the microscopic level.

Presented from the perspective of a concrete petrographer, this program will examine Type IL cement through observations from laboratory investigations and field concrete. Attendees will learn how the characteristics of Type IL cement may be identified petrographically, how its   microstructure and hydration characteristics compare with traditional Portland cement systems, and what those differences may mean when investigating cracking, scaling, finishing concerns, durability, and other concrete performance issues.

The presentation will also discuss the importance of distinguishing between conditions that may be related to cement chemistry and those resulting from mixture proportions, construction practices, curing, exposure,   or other factors. Through petrographic observations and case examples, participants will gain a better understanding of how Type IL cement is performing in practice and how petrography can assist in diagnosing concrete problems and making more informed material and specification decisions.

Presented by: Gerard Moulzolf, PG, Vice President of Operations, American Engineering Testing