A Concrete Strength Testing Technician is an individual who has demonstrated the knowledge and ability to properly perform, record, and report the results of four basic laboratory procedures related to the determination of concrete compressive and flexural strength.

Scope and Knowledge

The program requires a working knowledge of the following ASTM practices and test methods:

• C617 - Capping Cylindrical Concrete Specimens
• C1231/C1231M - Unbonded Caps for Concrete Cylinders
• C39/C39M - Compressive Strength of Cylindrical Concrete Specimens
• C78 - Flexural Strength of Concrete

Certification Requirements

ACI will grant certification only to those applicants who meet both of the following requirements:

1. A passing grade on the ACI written examination, and
2. Successful completion of the ACI performance examination.

The one-hour written examination is closed-book and consists of approximately 40 multiple choice questions. There are at least 8 questions on each of the practices and test methods. To pass the written examination, both of the following conditions must be met:

1. At least 60% correct for each of the required practices and test methods, and
2. A minimum score of 70% overall.

The performance examination is also closed-book and requires actual demonstration of the required practices and test methods. The examinee is judged on his/her ability to correctly perform all of the required steps for each procedure. Recertification is necessary every five years*, and requires successful completion of both the written and performance examinations.

*NOTE: Certifications initiated prior to January 1, 2008 were granted certification for six years. Due to a policy change, however, individuals initiating the certification process January 1, 2008 and later will be certified for five years.

Study Material

CP-19(13): Technician Workbook for ACI Certification of Concrete Strength Testing Technician This workbook contains information about the ACI Concrete Strength Testing Technician certification program, study questions, sample checklists, and a practice exam as well as reprints of all of the resource materials referenced by the certification examinations. The CSTT program covers the following ASTM practices and test methods: C39, C78, C617, and C1231.

Program Availability

Exams are generally set up on a company by company basis. ICACI does not have a laboratory facility, so the examinee will need to provide a laboratory location for the performance part of the exam. Contact the Certification committee at mailto:info@indianaaci.org for additional information.