What Is CSTT?

What CSTT Actually Stands For

On this site, CSTT stands for Concrete Strength Testing Technician. It is a certification for people who prepare and test hardened concrete specimens to determine strength. The acronym is shared by several unrelated credentials in other industries, so it is worth being precise: everything here concerns the concrete laboratory credential and nothing else.

If you landed here searching for the meaning of the abbreviation, our short explainers on what CSTT stands for and CSTT meaning cover the naming question directly. This article goes further and explains what the credential involves, how the exams work, and what candidates must master.

Who Issues the Credential and How Exams Are Delivered

The certification is offered by the American Concrete Institute (ACI). ACI does not run every exam session itself. Examinations are administered through ACI-approved Sponsoring Groups and resource centers, which are typically local chapters and industry organizations that schedule sessions, collect fees, and proctor the written and performance components.

This delivery model has practical consequences. Session dates, pricing, bundled training and membership discounts vary by sponsor, so there is no single national price list. If you are planning your timeline, see our guide to CSTT exam dates and scheduling and the overview of CSTT certification.

There is no specific education or work-experience prerequisite. A candidate does not need a degree or a minimum number of logged hours to sit for the exams, though hands-on familiarity with cylinders, caps and a compression machine makes the performance exam far less stressful. The CSTT requirements guide walks through eligibility in more detail.

The Four Examination-Objective Areas

The exam content is organized around four standards. These headings come from ACI's Job-Task Analysis, approved February 29, 2020 and editorially updated February 8, 2022. They are unweighted examination-objective areas, so you should not assume four equal quarters of the exam or try to apply a percentage split to them. For a deeper breakdown, see the CSTT exam domains guide.

The current program's technical basis is C617/C617M-15, C1231/C1231M-15, C39/C39M-18 and C78/C78M-18. Knowing which edition underlies the exam matters, because the details tested come from those versions of the standards.

Written Exam Plus Performance Exam

Certification requires passing two separate examinations, and you must pass both within one year.

The written examination

The written exam is one hour, closed book, and multiple choice. The number of questions is approximate rather than fixed. The current program page describes roughly 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. Because the two sources differ slightly, treat the count as approximate and do not plan around an exact number.

One point matters for preparation: with a minimum number of questions drawn from each standard, you cannot skip a standard and hope to compensate elsewhere. Even though the four areas are unweighted in the formal sense, each one reliably produces a block of questions.

The performance examination

The performance exam is also closed book. It assesses all four procedures using pass/fail checklists, so an examiner observes you carrying out each procedure and marks whether required steps were performed correctly. Simple non-programmable calculators are permitted.

To gauge how demanding this combination feels, read how hard the CSTT exam is.

How Scoring Works

Passing the written exam involves two simultaneous thresholds:

• At least 60% on each standard
• At least 70% overall

Both conditions must be met. A candidate who scores well overall but falls below 60% on one standard does not pass the written exam. That is why a balanced preparation plan matters more than perfecting your favorite topic. The CSTT passing score guide explains the rule with worked examples, and the CSTT pass rate article discusses what is and is not publicly known about outcomes.

Fees and Registration Mechanics

Because sponsors set their own pricing, the figures below are verified local 2026 examples, not national tariffs. Treat them as illustrations of how the cost structure typically works, and always confirm with your chosen sponsor.

Two details deserve attention. First, Ohio Concrete's member prices reflect Ohio Concrete membership, not ACI membership rates, so do not assume the discount transfers between organizations. Second, the Las Vegas Chapter lists an October 24, 2026 session, which shows that sessions are scheduled by sponsor on specific dates rather than in a continuous national window.

For a fuller treatment of budgeting, including what to compare between sponsors, see the CSTT certification cost breakdown.

The CP-19 Workbook and Technical References

The official study workbook is CP-19, 25th Edition (2022). ACI also accepts the 23rd and 24th editions because their technical basis is identical, which is useful if you can borrow or buy an older copy. The 25th-edition workbook excludes the ASTM standards themselves, so you would need to obtain those separately if you want the full standard text. It is listed at USD 71 for ACI members and USD 136 for non-members.

ACI also sells a separate on-demand preparation course. It is a learning aid only and does not award certification, so completing it does not substitute for passing the written and performance exams. For building a study plan around these materials, see the CSTT study guide and the CSTT training overview.

Where CSTT Holders Work

The credential is aimed at people who handle concrete specimens in a laboratory or testing setting. Typical employers are organizations that depend on documented compressive and flexural strength results:

• Commercial testing and inspection laboratories that test specimens for contractors, owners and engineers
• Ready-mix concrete producers with in-house quality control labs
• Precast and prestressed concrete plants that verify strength before stripping or shipping
• Construction materials and geotechnical engineering firms with materials testing divisions
• Public agencies, such as transportation departments, that verify concrete used on public works

For hiring patterns and role types, see CSTT jobs. For compensation, the CSTT salary guide discusses earnings qualitatively, and the is CSTT worth it analysis weighs cost against career benefit. Pay varies widely by region, employer and role, so no single figure should be treated as typical.

Sequencing Your Preparation Around the Four Procedures

Generic study habits matter less here than the order in which you learn the procedures. Because the standards build on one another, a sensible sequence follows the physical workflow of a strength test.

The reasoning: capping comes first because an error there corrupts everything downstream, and C1231 pairs naturally with C617. C39 is the centerpiece and deserves the most hands-on repetition. C78 is the one standard that tests beams rather than cylinders, so it benefits from a dedicated session at the end. Since each standard needs at least 60% on the written exam, finish with mixed review so no area is neglected. A condensed reference for the final days is available in the CSTT cheat sheet.

Certification Lifespan, Retakes, and Renewal

Certification lasts five years. Recertification is not a paperwork renewal: it requires passing both examinations again. Plan for that when you first certify, since your sponsor's recertification pricing may differ from first-time pricing, as the Las Vegas example above shows.

Retake rules are specific:

• If you fail a practical procedure, you are permitted a second same-day trial of that procedure.
• Subsequent re-examination covers the entire failed written or performance component, not just the missed items.
• If you do not complete both components within the one-year window, both must be retaken.

The one-year clock is the detail most likely to catch candidates off guard. If you pass the written exam early but delay the performance exam, you risk losing that progress. For definitions and an overview of the credential's basics, you can also review what CSTT certification is, what a CSTT is, and the alternate-phrasing explainer what does CSTT mean. To practice the exam format, visit the main CSTT practice test site.

Frequently Asked Questions