Sponsored by ASCE Continuing Education and ASCE's Construction Institute (CI)

Purpose and Background

The primary purpose of this webinar is to highlight the importance of the use of petrographic analysis as a part of any thorough investigation and on-site condition survey of a deteriorated concrete structure. Too often, conclusions concerning the nature or cause of deteriorated concrete, as well as the repair of the same, are based on visual observations only, particularly with structures exposed to chlorides (such as road de-icing salts). The resulting recommendations in such instances, more often than not, can lead to repair methods and techniques that can actually exacerbate the conditions, which in turn can lead to accelerated deterioration of the structure. The use of petrographic analysis can avoid the pitfalls associated with investigations based on on-site visual observations only. This webinar discusses the appropriate uses of and the types of concrete pathologies that can be determined with petrographic analysis.

Primary Discussion Topics

Petrographic analysis is a key component of the investigation of an existing deteriorated concrete structure. Petrographic analysis can be used to determine chemical and physical irregularities in concrete including the nature of the chemical attack, identification of reactive aggregate, strength, mixture proportion estimates (such as water/cement ratio), cement and fly-ash content, corrosion potential of embedded steel, degree of carbonation, aggregate size and distribution, presence of alkali-aggregate or sulfate reaction. This type of information can aid in the determination of the root cause of failure and extent of cracking, dusting, scaling, coating delamination and other types of concrete deterioration.

Learning Outcomes

• Determine the need for petrographic analysis as a part of a thorough investigation of deteriorated concrete
• Be knowledgeable of the different types of chemical and physical properties of concrete that can be determined by a petrographic analysis
•  Recognize the basic steps involved in the overall investigation of a deteriorated concrete structure 
• Be knowledgeable of the basic services that a qualified petrographic laboratory should provide as a part of analysis of concrete material samples
• Have an understanding of the different types of concrete deterioration that can be present in a concrete structure 
• Identify the different types of deterioration that can be identified by a petrographic analysis and the common diagnostics features of each
  

Webinar Benefits

 Understand the importance of using petrographic analysis in both the determination of the cause and proper repair of deteriorated concrete.

Assessment of Learning Outcomes

Students' achievement of the learning outcomes will be assessed via a short post-assessment (true-false, multiple choice and fill in the blank questions).

Intended Audience

• Engineers (structural, forensic and process)
• Architects

Webinar Outline

• Introduction to the Investigation of Concrete Deterioration
• Petrographic Analysis
• Concrete Pathology
• Concrete deterioration which is not directly influenced by reinforcement corrosion
• Concrete deterioration influenced by reinforcement corrosion
• Examples of Deterioration that can be established by Petrographic Analysis