- How the ACI Retake System Actually Works
- Fees, Sponsoring Groups, and What You'll Actually Pay
- Waiting Periods After a Failed Component
- Retaking Written vs. Performance: Different Challenges
- The 7 Written Domains Where Points Are Won or Lost
- Making the Most of Your Retake Window
- Recertification and the Grace Period
- Frequently Asked Questions
- There is no single ACI retake fee - each Sponsoring Group sets its own price, typically ranging from $450 to $660 or more.
- To pass the written exam, you must score at least 60% on each of the 7 individual ASTM sections AND 70% overall.
- Both the written and performance components must be passed separately; failing one does not cancel a passing score on the other (check with your specific...
- ACI certification is valid for 5 years; recertification requires passing both exam components again - there is no continuing-education alternative.
How the ACI Retake System Actually Works
The ACI Concrete Field Testing Technician - Grade I certification is administered entirely through ACI's network of 135+ Sponsoring Groups - local ACI chapters, concrete industry associations, state transportation agencies, and universities spread across North America and beyond. There is no centralized testing platform, no online proctoring option, and no single ACI headquarters where you walk in and reschedule. Every retake is coordinated directly with a Sponsoring Group, and that decentralized structure has real consequences for how fees and waiting periods work in practice.
Because Sponsoring Groups operate independently under ACI's certification framework, retake policies are not uniform. What ACI publishes at the national level are the passing standards - the 60%/70% written threshold and the pass/fail performance rubric. Everything around logistics - scheduling windows, retake timing, whether you can retake one component without repeating the other - is determined at the Sponsoring Group level. That makes contacting your specific group early in the process one of the highest-leverage actions you can take after a failed attempt.
Fees, Sponsoring Groups, and What You'll Actually Pay
ACI does not publish a single national retake fee. The full exam fee - which covers both the written and performance components - typically falls in the $450-$660+ range, though groups in higher cost-of-living markets or with smaller candidate pools may charge more. To use a published example: ACI Southern California charges $610 for members and $660 for non-members. Retake fees at a given Sponsoring Group may be a reduced component fee or the full exam fee, depending on their policy.
If you are an eligible veteran, the ACI Foundation's $250 veteran rebate can meaningfully reduce the financial burden of a retake. The GI Bill is also recognized for this certification, making it reimbursable for qualified service members and veterans. If cost is a barrier to scheduling your retake promptly, these programs are worth investigating before delaying your preparation further.
Fee Considerations Before You Register for a Retake
Before paying a retake fee, confirm the following with your Sponsoring Group:
- Does the retake fee cover one component or both?
- Is there a reduced fee if you only need to retake the written or only the performance?
- What is the next available exam date, and does it fall within any waiting period that applies to you?
- Are veteran rebate or GI Bill reimbursement forms processed before or after payment?
For broader context on the employment landscape - including which employers pay for exam and retake fees directly - see our article on ACI Concrete Field Testing Jobs: Hiring Requirements 2026. Many contractors and testing labs cover exam costs for sponsored employees, which changes the financial calculus of a retake entirely.
Waiting Periods After a Failed Component
ACI's national certification documentation does not prescribe a universal mandatory waiting period between a failed attempt and a retake. This stands in contrast to some other credentialing bodies that enforce 30-, 60-, or 90-day lockout windows. In practice, your waiting period is largely determined by when the next exam is scheduled by your Sponsoring Group.
Most Sponsoring Groups hold exams on a periodic basis - some monthly, others quarterly, a few only one to three times per year. If a group runs exams quarterly and you just missed a sitting, your de facto waiting period could be three months regardless of any formal policy. This makes it critical to research your local group's exam calendar immediately after a failed attempt rather than waiting until you feel "ready" to look into scheduling.
If your local Sponsoring Group's next exam is too far out, ACI's network allows candidates to sit for the exam through any Sponsoring Group - not just the one in your home market. Traveling to a nearby city for an earlier retake date is a legitimate and commonly used option. Confirm with the receiving group that they accept out-of-area candidates and clarify any administrative requirements they may have.
Retaking Written vs. Performance: Different Challenges
The ACI Grade I exam has two entirely separate components, and the reasons candidates fail each one are quite different. Understanding those differences should shape how you approach a targeted retake.
The Written Component
The written exam consists of 55 multiple-choice questions across 60 minutes, covering all seven ASTM test method domains. The dual threshold - at least 60% on each of the 7 individual sections and 70% overall - is what catches many candidates off guard. You can score well globally and still fail because a single section where you had 4-6 questions pulled your section score below 60%. With only 5-10 questions assigned to each test method, a single missed question can have an outsized impact on your section percentage.
When retaking the written exam, ask your Sponsoring Group whether they can share which sections you underperformed in. Some groups provide section-level feedback; others provide only a pass/fail result. If you receive section-level data, prioritize those domains in your retake preparation. If you receive only a total score, treat all seven domains as fair game and weight your review toward the test methods with the most complex procedural details - ASTM C138, C231, C173, and C31 tend to generate the most nuanced questions.
Practice questions tied specifically to ACI's CP-1 content are the most efficient preparation tool. Our ACI practice test platform structures questions by domain so you can immediately isolate weak sections and track your per-section accuracy before your retake date.
The Performance Component
The performance exam is a hands-on demonstration. Candidates must correctly execute the required steps for six ASTM procedures and orally describe the ASTM C172 sampling procedure. Passing is pass/fail - either you perform the required steps correctly or you do not. There is no partial credit for "almost right" technique.
Common performance failures involve procedural sequencing errors (performing steps out of order), equipment handling mistakes, and failure to meet the specific tolerances written into the ASTM standards - for example, the rod penetration depth and stroke count requirements in ASTM C31 cylinder making, or the pressure gauge reading sequence in ASTM C231. ACI explicitly states that certification is not training, meaning the performance exam assumes you already have hands-on familiarity. If you failed the performance component, genuine field practice - not just reading CP-1 - is the correct remediation.
The 7 Written Domains Where Points Are Won or Lost
Because the per-section minimum is what fails most written candidates, here is a focused look at each domain and the specific knowledge it demands on a retake:
Domain 1: ASTM C1064/C1064M - Temperature of Freshly Mixed Concrete
Questions focus on thermometer immersion depth, minimum immersion time (2 minutes), allowable temperature ranges, and the requirement that the test be completed within 5 minutes of obtaining the sample.
- Know the minimum and maximum freshly mixed concrete temperature limits for various spec conditions
- Understand thermometer accuracy and calibration requirements
Domain 2: ASTM C172/C172M - Sampling Freshly Mixed Concrete
This is the oral description domain on the performance exam and a written domain. Questions test the composite sample requirement (two or more portions), the time window for completing sampling and testing, and prohibited sampling locations.
- Composite samples must be obtained over a period not exceeding 15 minutes
- Testing must begin within 5 minutes of completing sampling
Domain 3: ASTM C143/C143M - Slump Test
Focus on the tamping rod diameter and length, the three equal layer requirement, 25 strokes per layer, rodding distribution pattern, the 5-second inversion and lift time, and the measurement reference point.
- The mold must be dampened and placed on a flat, moist, non-absorbent surface
- The slump cone must be raised vertically in 5 ± 2 seconds
Domains 4, 5 & 6: C138, C231, C173 - Unit Weight and Air Content
These three domains are closely related and frequently confused with each other. C138 covers the gravimetric (calculation-based) air content method. C231 is the pressure meter method for normal-weight concrete. C173 is the volumetric method used for lightweight or air-entrained concrete with porous aggregates. Know which method applies when.
- C231 uses the Type B pressure meter; know the calibration procedure
- C173 uses a roll-agitation process with isopropyl alcohol; know the bowl volume and reading protocol
- C138 requires accurate scale calibration and the correct formula for yield and air content calculations
Domain 7: ASTM C31/C31M - Making and Curing Concrete Test Specimens in the Field
The most procedure-dense domain. Questions cover cylinder size options, consolidation method selection (rodding vs. vibration based on slump), number of layers, curing temperature ranges, and initial vs. final curing requirements.
- Standard 4×8 and 6×12 cylinders have different rodding stroke counts
- Initial curing: maintain 60-80°F for first 24 hours; protect from vibration and disturbance
- Know the timeframes for transporting cylinders to the lab after initial curing
| Domain | ASTM Standard | Exam Format | Key Passing Risk |
|---|---|---|---|
| Temperature | C1064/C1064M | Written + Performance | Immersion time and 5-minute rule |
| Sampling | C172/C172M | Written + Oral Description | Composite sample window and prohibited locations |
| Slump | C143/C143M | Written + Performance | Stroke count, layer uniformity, lift timing |
| Unit Weight / Gravimetric Air | C138/C138M | Written + Performance | Calculation formula accuracy |
| Air Content (Pressure) | C231/C231M | Written + Performance | Meter calibration, aggregate correction factor |
| Air Content (Volumetric) | C173/C173M | Written + Performance | Alcohol addition and agitation sequence |
| Making & Curing Specimens | C31/C31M | Written + Performance | Consolidation method selection, curing temps |
Making the Most of Your Retake Window
The gap between your failed attempt and your retake date - whether it's three weeks or three months - has a specific, efficient use when you organize it around the seven ACI domains rather than generic study habits. Here is a focused approach:
Diagnose and Anchor
- Pull your section-level score feedback if available from your Sponsoring Group
- Take a full-length ACI practice exam under timed, closed-book conditions to establish your baseline
- Identify which of the 7 domains fall below 60% accuracy - these are your mandatory focus areas
- Read the CP-1, 41st Edition sections corresponding to your weakest domains only
Deep Work on C31 and C138 / C231 / C173
- These domains have the most procedural complexity and the most calculation-based questions
- Write out the C138 yield and gravimetric air content formulas from memory; practice with numbers until they are automatic
- Distinguish C231 from C173 application scenarios - a common source of written exam confusion
Full-Domain Review and Timed Practice
- Complete domain-specific question sets for all 7 areas, targeting 70%+ on each before your retake
- If retaking the performance exam, arrange at least two hands-on practice sessions with actual equipment
- Review PPE requirements - safety-toe shoes, long pants, sleeved shirt, safety glasses are required; arriving unprepared disqualifies you
Key Takeaway
The written exam's per-section 60% minimum means passing your weakest domain matters more than improving your best ones. Allocate retake prep time proportionally to your section gaps, not equally across all seven areas.
For candidates who are planning their retake while also preparing for entry-level field work, our article on ACI Concrete Field Testing Jobs: Hiring Requirements 2026 covers what employers expect from newly certified technicians and how the Grade I certification fits into a career path in construction materials testing.
Recertification and the Grace Period
The ACI Grade I certification is valid for 5 years from the date of certification. There is no continuing education pathway to renew - when your certification expires, recertification requires passing both the written and performance components again, to the same standards as the initial exam. This is a meaningful distinction from many other trade certifications that allow CE credits or open-book renewals.
ACI provides a 1-year grace period after expiration. During this window, your certification has lapsed but you may still recertify through the standard exam process without additional penalties. After the grace period closes, you are treated as a new candidate with no grandfather provisions.
If you are approaching your 5-year mark, treat recertification with the same urgency as a retake - especially for the performance component, where hands-on procedural memory fades without regular field use. Scheduling your recertification exam well before expiration gives you a buffer if you need a retake before the grace period closes.
Everything you need to practice for both an initial attempt and a recertification retake is available through our ACI practice test platform, with questions organized by domain, timed exam simulations, and performance tracking so you can verify you're above both the per-section 60% threshold and the 70% overall minimum before exam day.
Frequently Asked Questions
This depends on the specific policy of your Sponsoring Group. ACI administers the certification through independent Sponsoring Groups, and component retake policies vary. Contact your group directly and ask in writing whether a passing written score can be held while you retake only the performance component - and if so, for how long that score remains valid.
You must score at least 60% on each of the 7 individual ASTM domain sections AND achieve a 70% overall score. Both thresholds must be met simultaneously. Passing one without the other results in a failed written exam.
ACI does not publish a universal mandatory waiting period at the national level. Your practical waiting period is determined by when the next exam is offered by an accessible Sponsoring Group. If your local group's schedule is infrequent, you may sit for the exam through any other Sponsoring Group in ACI's network.
The ACI Foundation's $250 veteran rebate is tied to eligible veterans taking the ACI certification exam. Contact the ACI Foundation directly to confirm whether the rebate applies to retake attempts or is limited to a first-time certification sitting, as program terms can be updated.
Yes. A simple calculator is permitted for both the written and performance components. However, the permitted functions are limited to addition, subtraction, multiplication, division, and square root. Scientific or programmable calculators are not allowed. This is particularly relevant for C138 density and yield calculations on the written exam.