What Is CSTT Certification?

What the Credential Actually Is

Concrete Strength Testing Technician certification is a focused, technician-level credential that verifies you can correctly prepare and break concrete test specimens and handle the procedures behind reported strength results. It is a narrow program by design. Instead of surveying all of concrete technology, it tests four specific standardized procedures: capping cylinders, using unbonded caps, compressive strength testing of cylinders, and flexural strength testing of beams.

The name matters because several credentials in other fields share the same four-letter abbreviation. This article, and this site, concern only the ACI Concrete Strength Testing Technician program. It is not the Field Testing Technician Grade I credential, and it is not the combined Laboratory Testing Technician Level 1 credential, even though those programs sit nearby in the ACI catalog. If you are still sorting out terminology, our short explainers on what CSTT stands for and the meaning of CSTT cover the naming question quickly.

Who Issues It and How Exams Are Delivered

The certifying body is the American Concrete Institute (ACI). Examinations are not taken at a single national testing center. They are administered through ACI-approved Sponsoring Groups and resource centers, which are often local ACI chapters or regional concrete associations. That structure shapes your experience in several practical ways:

• Session dates, locations and capacity are set by the sponsoring group, not by ACI headquarters.
• Pricing varies from one sponsor to the next, because each sets its own fee schedule.
• Some sponsors bundle a review session, the workbook and both exams, while others sell exam-only registration.
• Performance exams require equipment and a proctor evaluating your technique, so the number of seats can be limited.

For scheduling realities, see our guide to CSTT exam dates, testing windows and deadlines.

The Four Examination-Objective Areas

The program's Job-Task Analysis, approved February 29, 2020 and editorially updated February 8, 2022, organizes the written and performance examination objectives under four headings. One point is easy to get wrong: these four areas are unweighted. They are not four equally weighted domains, and you should not assume each represents a quarter of your grade in some formula. The scoring rules described below treat each standard separately. For the technical basis, the current program points to C617/C617M-15, C1231/C1231M-15, C39/C39M-18 and C78/C78M-18.

For a deeper treatment of each area, read our complete guide to all four CSTT content areas.

Written and Performance Exam Format

The credential has two distinct components, and you must pass both.

The written examination

The written exam runs one hour, is closed book, and is multiple choice. The number of questions is best described as approximate. The current ACI program page describes approximately 40 questions with at least eight per standard, while Certification Program Policy CPP 620.2-19 describes approximately 35 to 40 questions with 8 to 10 per standard. Rather than fixing on an exact count, plan for roughly 35 to 40 items spread across the four standards, with every standard well represented. That means no single standard can be skipped without consequence.

The performance examination

The performance exam is separate and also closed book. An evaluator assesses all four procedures using pass/fail checklists. You are demonstrating the actual steps of each procedure in correct order, not describing them. Simple non-programmable calculators are permitted. Because checklists are pass/fail, a skipped or reordered step can matter even when your final numbers are correct.

Candidates often ask which half is harder. Our analysis in How Hard Is the CSTT Exam? breaks down where people tend to struggle.

How Passing Works

The written exam has a two-part standard. You need at least 60% on each standard and at least 70% overall. Both conditions must be met at the same time.

For the performance exam, each procedure is judged on a pass/fail checklist rather than a percentage. A deeper walkthrough of the numbers is in CSTT Passing Score: Exactly What You Need to Pass, and we discuss what published data does and does not tell us in CSTT Pass Rate: What the Data Shows.

Eligibility and the One-Year Window

There is no specific education or work-experience prerequisite for this certification. You do not need a degree, a minimum number of field hours, or a prior ACI credential to register. That makes it accessible to new lab hires, though accessible is not the same as easy; the exams assume you have handled the procedures or practiced them deliberately.

The timing rule is where candidates get caught. You must pass both the written and performance examinations within one year. Here is how the retake rules work:

• If you fail a practical procedure, you are permitted a second trial on the same day.
• Subsequent re-examination covers the entire failed written or performance component, not just the part you missed.
• If the one-year completion window closes before you finish, both components must be retaken.

Plan your sessions so there is slack for at least one retake inside the window. More detail on eligibility is available in CSTT Requirements: Eligibility, Prerequisites & How to Qualify.

Fees, Workbook and Local Pricing

There is no single national fee for this exam, because sponsoring groups set their own prices. What can be said is anchored in two verified 2026 local examples and the official workbook listing. Treat the local numbers as examples, not tariffs.

The workbook

The current study workbook is CP-19, 25th Edition (2022). ACI also accepts the 23rd and 24th editions because their technical basis is identical. The 25th-edition workbook is listed at USD 71 for ACI members and USD 136 for non-members, and it excludes the ASTM standards themselves. ACI identifies first-printing errata, but the linked errata document requires a sign-in, and the paid workbook contents were not reviewed for this article, so verify corrections directly if you buy an early printing.

Two local fee examples

Two cautions. First, the Las Vegas Chapter lists an October 24, 2026 session, which illustrates that sessions are dated events rather than on-demand appointments. Second, the Ohio Concrete figures are priced by Ohio Concrete membership, not ACI membership, so do not assume an ACI member rate applies there. ACI also sells a separate on-demand preparation course, but it does not award certification.

For a budgeting framework, see CSTT Certification Cost: Complete Pricing Breakdown.

After You Pass: Five Years and Recertification

Certification lasts five years. Recertification is not a paperwork renewal: it requires passing both examinations again. That has a planning implication. Whatever you do on the job over five years may drift from the exact procedures in the standards, so build a refresher into your recertification timeline rather than relying on daily habit.

Who Uses This Credential

The credential is relevant wherever concrete strength results are produced and relied upon. Typical environments include:

• Independent testing and inspection laboratories that break cylinders and beams for clients
• Ready-mix producers with quality control laboratories
• Construction materials testing divisions of engineering and geotechnical firms
• Precast and paving contractors where flexural strength is a controlling property
• Public agencies and owners' verification laboratories

Job postings and project specifications sometimes name ACI certification as a requirement for personnel performing or reporting strength tests, which is a major reason technicians pursue it. We explore the hiring side in CSTT jobs, the earnings question in the CSTT salary guide, and the career case in Is the CSTT Certification Worth It?

Sequencing Your Preparation

Because the four standards build on one another, the order you study them matters more than any generic technique. Capping feeds directly into compressive testing, so learn them in that sequence. A compact plan:

For a fuller approach, see our CSTT study guide, keep the one-page CSTT cheat sheet handy for last-minute review, and use the CSTT practice tests to check each standard separately against the 60% floor.

Frequently Asked Questions