- What the Two-Part Exam Actually Looks Like
- Inside the Written Exam: 55 Questions, 7 Domains
- Inside the Performance Exam: 6 Tests and an Oral
- Passing Standards: Where Most Candidates Get Surprised
- Which Domains Demand the Most Attention
- PPE, Logistics, and What to Bring on Test Day
- Registration, Fees, and Veteran Benefits
- A Domain-by-Domain Prep Schedule
- Validity, Expiration, and Recertification Rules
- Frequently Asked Questions
- The written exam has 55 multiple-choice questions across 7 ASTM domains; you must score at least 60% in every individual section AND 70% overall to pass.
- The performance exam is strictly pass/fail - every required procedural step must be completed correctly, with no partial credit.
- Fees are set by individual Sponsoring Groups and typically range from $450 to $660+; the ACI Foundation offers a $250 veteran rebate.
- Both exams are closed-book; only a simple four-function calculator with square root is permitted.
What the Two-Part Exam Actually Looks Like
The ACI Concrete Field Testing Technician - Grade I certification is administered entirely in person through ACI's network of more than 135 Sponsoring Groups - local ACI chapters, concrete associations, state transportation agencies, and universities. There is no computer-based testing, no remote option, and no single national testing date. Your experience on exam day is shaped by the Sponsoring Group running the event in your area.
What does remain consistent everywhere is the structure: every candidate sits through two separate components - a written exam and a hands-on performance exam - and must pass both independently. Passing one does not carry over if you fail the other. ACI is explicit that the certification is not a substitute for training; it is a verification that you already know how to perform freshly mixed concrete field testing to ASTM standards.
Inside the Written Exam: 55 Questions, 7 Domains
The written component consists of exactly 55 multiple-choice questions delivered in a 60-minute window. That works out to roughly 65 seconds per question - enough time for straightforward recall but not enough to derive answers from first principles. The exam is closed book, meaning you cannot reference CP-1 or any ASTM standard during the test.
The 55 questions are distributed across 7 domains, with each domain drawing 5 to 10 questions. Those domains map directly to the ASTM test methods covered in the certification:
Domain 1 - ASTM C1064/C1064M: Temperature of Freshly Mixed Hydraulic-Cement Concrete
Tests knowledge of thermometer immersion depth, contact time, acceptable temperature ranges for placement, and timing constraints from sampling to measurement.
- Minimum immersion depth and contact time requirements
- Acceptable temperature measurement window after sampling
- Equipment calibration expectations
Domain 2 - ASTM C172/C172M: Sampling Freshly Mixed Concrete
Covers composite sampling procedures, time limits from first to last portion, where in the discharge sampling may occur, and situations that invalidate a sample.
- Number of individual portions for a composite sample
- Elapsed time limits between first increment and completion of testing
- Prohibited sampling points in the discharge stream
Domain 3 - ASTM C143/C143M: Slump of Hydraulic-Cement Concrete
Focuses on cone filling layers, rodding counts, tamping, and the precise measurement technique that produces a valid slump reading.
- Three-layer filling sequence and 25-rod-stroke requirement per layer
- Maximum elapsed time from sampling to slump measurement
- Valid versus shear slump interpretation
Domain 4 - ASTM C138/C138M: Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
Covers container calibration, rodding versus vibration consolidation criteria, density calculation formulas, and how to derive yield and gravimetric air content from measured values.
- Container volume determination and calibration procedures
- Rodding vs. vibration consolidation thresholds
- Unit weight formula and yield calculation
Domain 5 - ASTM C231/C231M: Air Content by the Pressure Method
The pressure meter method - the most commonly used air test on job sites. Expect questions on meter calibration, the aggregate correction factor, and procedural steps that affect meter accuracy.
- Aggregate correction factor procedure
- Pump pressure requirements and stabilization
- Why this method cannot be used with lightweight or porous aggregates
Domain 6 - ASTM C173/C173M: Air Content by the Volumetric Method
The volumetric (roll-a-meter) method is required when the pressure method cannot be used. Candidates must understand the isopropyl alcohol addition, rolling and inversion protocol, and reading the graduated neck.
- Volume of isopropyl alcohol required
- Rolling and inversion sequence
- Appropriate concrete types for this method
Domain 7 - ASTM C31/C31M: Making and Curing Concrete Test Specimens in the Field
The broadest domain. Covers cylinder and beam specimen fabrication, consolidation method selection based on slump, curing temperature ranges, transport requirements, and initial versus final curing distinctions.
- Slump thresholds for rodding vs. internal vibration
- Initial curing temperature range and duration
- Cylinder cap requirements before final curing transport
Because each domain carries its own 60% floor, weak performance in a single ASTM method can fail you on the written exam even with a strong overall score. You can review question style and practice domain-by-domain at the ACI Exam Prep practice test platform.
Inside the Performance Exam: 6 Tests and an Oral
The performance component requires you to physically demonstrate six ASTM test methods in front of an ACI-trained examiner. You will also be asked to give an oral description of the C172 composite sampling procedure. The six demonstrated tests are:
- Temperature measurement per ASTM C1064
- Slump test per ASTM C143
- Unit weight and yield per ASTM C138
- Air content by pressure meter per ASTM C231
- Air content by volumetric meter per ASTM C173
- Making and curing cylinders or beams per ASTM C31
Each test is evaluated as a strict pass/fail against a checklist of required procedural steps. There is no partial credit. If you skip a step, perform it out of sequence in a way that violates the standard, or make a critical technique error, that test fails. Because you must correctly perform all required steps, a single procedural shortcut on test day can end an otherwise strong performance.
Passing Standards: Where Most Candidates Get Surprised
| Component | Format | Passing Requirement | Closed Book? |
|---|---|---|---|
| Written Exam | 55 multiple-choice, 60 minutes | ≥60% on each of 7 domain sections AND ≥70% overall | Yes |
| Performance Exam | Hands-on demonstration of 6 ASTM tests + C172 oral | Pass/fail - all required steps must be completed correctly | Yes (no references during demo) |
The dual threshold on the written exam trips up candidates who study certain domains heavily and neglect others. Even if you average well above 70% overall, a single domain below 60% is a failing score. This means your study plan cannot afford a single weak domain - including the ones that feel intuitively obvious, like temperature measurement.
For the performance exam, the surprise is procedural rather than conceptual. Candidates who understand the theory of the C231 pressure meter sometimes still fail the performance because they skip the aggregate correction factor step or fail to stabilize the pump pressure before taking a reading. Hands-on repetition is the only real preparation for this component.
Which Domains Demand the Most Attention
While ACI does not publish pass rates or domain-level difficulty data, the content of the domains themselves points to where preparation time pays off most.
ASTM C31 (Domain 7) is the largest domain by content. It covers both cylinders and beams, two consolidation methods, two distinct curing phases, transport conditions, and temperature monitoring requirements. With up to 10 questions allocated, this domain can significantly affect both your section score and your overall total.
ASTM C138 (Domain 4) involves calculation. You need to know the density formula, how to derive yield from batch design data, and how to compute gravimetric air content. The simple calculator (four functions plus square root only) is permitted - but you must know which formulas to apply and in what order.
ASTM C231 and C173 (Domains 5 and 6) are often confused with each other because both measure air content. Questions frequently probe when each method is appropriate, particularly the limitation of the pressure method with porous or lightweight aggregates. Knowing not just how each test works but when each is used is essential.
For deeper coverage of what CP-1 addresses in each domain, see ACI CP-1 Study Material: What the 41st Edition Covers.
PPE, Logistics, and What to Bring on Test Day
ACI mandates specific personal protective equipment for the performance exam. Arriving without it disqualifies you from participating:
- Safety-toe shoes (steel-toe or composite-toe; sneakers and work boots without toe protection are not acceptable)
- Long pants (no shorts, regardless of weather or season)
- Sleeved shirt (short sleeves are acceptable; no tank tops or sleeveless shirts)
- Safety glasses
The equipment used in the performance exam - slump cone, unit weight bucket, pressure meter, volumetric meter, cylinder molds, tamping rod, vibrator - is provided by the Sponsoring Group. You do not bring your own tools.
For the written exam, you may bring a simple calculator capable of addition, subtraction, multiplication, division, and square root only. Programmable calculators, smartphones used as calculators, and scientific calculators with memory functions are not permitted.
Registration, Fees, and Veteran Benefits
Because ACI's Sponsoring Group model distributes exam administration to local organizations, fees vary by location. Typical ranges run from approximately $450 to $660 or more. As a concrete example, ACI Southern California charges $610 for members and $660 for non-members. Fees at state DOT-sponsored events or university-hosted sessions may differ in either direction.
There are no education or experience prerequisites for registration. ACI does not require a certain number of years in the industry, a degree, or any prior coursework. The certification is open to anyone who can pay the registration fee and pass both components.
Key Takeaway
The ACI Foundation's $250 veteran rebate is a meaningful offset against registration costs, and the certification is GI Bill reimbursable. Active-duty and veteran candidates should contact their Sponsoring Group and the ACI Foundation directly to confirm current program availability before registering.
To find the Sponsoring Group nearest you and check upcoming exam dates, visit ACI's official Sponsoring Group directory. Exam dates are not centrally scheduled and vary by region - some groups offer exams quarterly, others only once or twice per year.
A Domain-by-Domain Prep Schedule
Given the dual threshold structure of the written exam, an effective study plan allocates time by domain complexity rather than by generic weekly blocks. The following four-week framework sequences domains by interdependency and calculation demand:
Foundation: C172 Sampling + C1064 Temperature
- Master C172 composite sampling protocol - this anchors every other test method and appears as the oral component in the performance exam
- Learn C1064 immersion requirements and timing constraints; 5 questions maximum makes this completable in a single focused session
- Use spaced repetition flashcards for numerical thresholds (contact times, temperature windows)
Procedure-Heavy Tests: C143 Slump + C138 Density/Yield
- Drill C143 layer counts, rod strokes, and elapsed time limits until they are automatic
- Work C138 calculation problems by hand using only the permitted simple calculator; practice unit weight, yield, and gravimetric air content formulas
- Begin hands-on practice with physical equipment if accessible
Air Content Methods: C231 Pressure + C173 Volumetric
- Study both methods side-by-side to understand when each applies - aggregate type is the critical differentiator
- Practice the aggregate correction factor procedure for C231 in detail; this step is commonly missed in the performance exam
- Review the isopropyl alcohol volume and rolling protocol for C173
Largest Domain: C31 Specimens + Full Simulated Exam
- Cover both cylinder and beam fabrication, slump-based consolidation selection, initial vs. final curing, and transport requirements
- Take a full timed 55-question written practice exam at ACI Exam Prep and identify any domain still below 60%
- Conduct a full physical run-through of all six performance tests in sequence
Validity, Expiration, and Recertification Rules
ACI Grade I certification is valid for five years from the date of certification. There is a one-year grace period after expiration during which a lapsed technician can recertify, but ACI does not state that work performed during the grace period is automatically acceptable - employers and project specifications may have stricter requirements.
When it comes time to recertify, ACI does not offer a continuing education pathway or a shortened exam. Recertification requires passing both the written exam and the performance exam again, in full, under the same standards as the original certification. The 7-domain written structure, the 60%/70% dual threshold, and the pass/fail performance checklist all apply identically to recertification candidates.
This is worth noting early in a technician's career: the skills tested on the performance exam are perishable. Technicians who have been in the field for five years and have regularly performed these tests may find recertification straightforward. Those whose roles shifted away from field testing may need a structured refresher before the performance component.
For a deeper look at both exam components and how to approach written preparation, see the full breakdown in ACI Exam Written vs Performance: Key Differences 2026.
Frequently Asked Questions
No. Both components must be passed independently. A passing written score does not result in certification on its own. You must pass both the written and performance exams to receive the ACI Concrete Field Testing Technician - Grade I certification. Check with your Sponsoring Group about whether you must retake both components or only the failed component at their specific event.
You fail the written exam. The dual threshold requires a minimum of 60% in every individual ASTM domain section AND a 70% overall score. Meeting the overall threshold alone is not sufficient. This is why balanced preparation across all seven domains is essential - not just chasing a strong average.
No. ACI states there are no prerequisites for education or field experience. Anyone can register through a Sponsoring Group. ACI explicitly notes that the certification is not training - it is a skills verification. Candidates without hands-on experience should pursue practical training before the performance exam, as procedural accuracy is evaluated strictly.
No. Only a simple calculator capable of addition, subtraction, multiplication, division, and square root is permitted. Programmable calculators, graphing calculators, and smartphones used as calculators are not allowed. The calculations on the exam - primarily unit weight, yield, and air content formulas from C138 - are designed to be solvable with basic arithmetic.
Exams are offered exclusively through ACI's Sponsoring Groups, which include local ACI chapters, state DOTs, concrete industry associations, and universities. There is no single national exam calendar. Visit the ACI website's Sponsoring Group directory to find the group in your region, then contact them directly for upcoming exam dates and registration fees, which typically range from $450 to $660 or more depending on the group and your membership status.