100+ Free ACI Field Testing I Practice Questions

Pass your ACI Concrete Field Testing Technician Grade I exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately

Not publicly disclosed by ACI Pass Rate

100+ Questions

100% Free

1 / 10

Question 1

Score: 0/0

Per ASTM C172, when sampling freshly mixed concrete from a stationary mixer (other than paving mixers), what is the maximum elapsed time allowed between obtaining the first and final portions of the composite sample?

5 minutes

10 minutes

15 minutes

20 minutes

to track

2026 Statistics

Key Facts: ACI Field Testing I Exam

7 ASTM

Tests on the Exam

ACI CP-1 (C172, C143, C1064, C138, C231, C173, C31)

55 MC

Written Exam Questions

ACI CP-1 (1 hour, closed book)

70% / 60%

Passing Score

70% overall AND 60% per ASTM method

5 Years

Certification Validity

ACI certification policy

$610-$670

2026 Exam Fee

ACI chapter pricing (ACI/SCC member/non-member)

IBC Required

Code Recognition

IBC and ACI 318 for acceptance testing

ACI Grade I is the entry-level concrete field testing credential required by the IBC and ACI 318 for acceptance testing of structural concrete. The exam combines a 1-hour, 55-question closed-book written test with a hands-on performance exam covering all seven ASTM standards: C172 (sampling), C143 (slump), C1064 (temperature), C138 (unit weight/yield), C231 (pressure air), C173 (volumetric air), and C31 (making and curing specimens). To pass, candidates must score at least 60% on each individual ASTM method and 70% overall on the written, plus demonstrate proficiency on every test during the performance exam. The certification is valid for 5 years, has no formal prerequisites, and opens doors to higher ACI credentials such as Strength Testing Technician and Concrete Construction Special Inspector. Median wages for concrete testing technicians align with BLS construction inspector data of roughly $65,000 per year.

Sample ACI Field Testing I Practice Questions

Try these sample questions to test your ACI Field Testing I exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Per ASTM C172, when sampling freshly mixed concrete from a stationary mixer (other than paving mixers), what is the maximum elapsed time allowed between obtaining the first and final portions of the composite sample?

A.5 minutes

B.10 minutes

C.15 minutes

D.20 minutes

Explanation: ASTM C172/C172M requires that the elapsed time between obtaining the first and final portions of the composite sample not exceed 15 minutes. Transportation and remixing of the sample must be completed as quickly as possible, and testing for slump, air content, and temperature must begin within 5 minutes of obtaining the final portion.

2According to ASTM C172, how many portions must be taken to form a composite sample from a stationary mixer?

A.At least 2 regularly spaced portions

B.At least 3 regularly spaced portions, but not from the very start or very end of the discharge

C.Exactly 5 portions

D.A single portion from the middle of the load

Explanation: ASTM C172 requires at least two regularly spaced portions taken during the middle portion of the batch — never from the very first or last part of the discharge. These portions are combined and remixed with a shovel to form a composite sample that is representative of the batch.

3Per ASTM C172, what is the minimum size of a composite sample used for strength tests of freshly mixed concrete?

A.0.5 ft^3 (14 L)

B.1 ft^3 (28 L)

C.2 ft^3 (56 L)

D.3 ft^3 (85 L)

Explanation: ASTM C172 specifies a minimum composite sample size of 1 ft^3 (28 L) for strength testing. Smaller samples may be used for routine tests such as slump, temperature, or air content, but strength specimens require at least 1 cubic foot to ensure a representative sample of the batch.

4Per ASTM C172, within what maximum time after obtaining the final sample portion must tests for slump, temperature, and air content be started?

A.5 minutes

B.10 minutes

C.15 minutes

D.30 minutes

Explanation: ASTM C172 requires that tests for slump, temperature, and air content be started within 5 minutes after obtaining the final portion of the composite sample. Molding of strength specimens must begin within 15 minutes of fabricating the composite sample. These time limits prevent changes in properties due to hydration and moisture loss.

5Per ASTM C172, molding of specimens for strength tests must be started within what time after fabricating the composite sample?

A.5 minutes

B.10 minutes

C.15 minutes

D.20 minutes

Explanation: ASTM C172 requires molding of strength specimens to begin within 15 minutes after fabricating the composite sample. This time limit ensures that the cast cylinders or beams represent the condition of the concrete at the time of placement and are not affected by prolonged delay before consolidation.

6Per ASTM C172, from which portion of a truck mixer (revolving-drum truck) discharge should sampling be done?

A.Only from the first 15% of the load

B.Only from the last 15% of the load

C.From approximately the middle portion of the batch (not from the very first or very last portions)

D.Continuously across 100% of the discharge

Explanation: ASTM C172 requires that samples from a truck mixer be taken at two or more regularly spaced intervals during discharge of the middle portion of the batch. The very beginning and very end of the discharge are avoided because they are not representative of the average concrete in the load.

7Per ASTM C172, how should the composite sample be protected between obtaining the sample and performing tests?

A.Left uncovered in direct sunlight to simulate field conditions

B.Protected from sun, wind, and other sources of rapid evaporation and from contamination

C.Refrigerated to below 40 degrees F

D.Heated to 90 degrees F to accelerate hydration

Explanation: ASTM C172 requires protecting the composite sample from sun, wind, and other sources of rapid evaporation, and from any source of contamination between sampling and testing. Excessive moisture loss or temperature change would invalidate test results by changing the concrete's properties before it can be measured.

8Per ASTM C172, after the composite sample is collected from two or more portions of the batch, what must be done before performing any tests?

A.Sieve the sample to remove coarse aggregate

B.Remix the sample with a shovel to ensure uniformity

C.Add water to restore slump

D.Let the sample sit undisturbed for 5 minutes

Explanation: ASTM C172 requires that the combined portions be remixed with a shovel the minimum amount necessary to ensure uniformity before tests are performed. This remixing ensures that segregation between individual portions is eliminated. Adding water or sieving the sample would alter the concrete and is prohibited.

9Per ASTM C143, what is the inside diameter of the top opening of the slump cone (mold)?

A.2 inches (50 mm)

B.4 inches (100 mm)

C.6 inches (150 mm)

D.8 inches (200 mm)

Explanation: ASTM C143/C143M specifies a slump cone (mold) with a top inside diameter of 4 inches (100 mm), a bottom inside diameter of 8 inches (200 mm), and a height of 12 inches (300 mm). These exact dimensions are required to produce comparable slump measurements across job sites.

10Per ASTM C143, the slump mold has bottom and top inside diameters, respectively, of:

A.4 in. and 8 in.

B.8 in. and 4 in.

C.6 in. and 12 in.

D.12 in. and 6 in.

Explanation: The ASTM C143 slump mold has an 8-inch (200 mm) bottom inside diameter and a 4-inch (100 mm) top inside diameter, with a 12-inch (300 mm) height. It is a frustum of a cone with the larger opening placed on the base plate.

About the ACI Field Testing I Exam

The ACI Concrete Field Testing Technician Grade I certification validates a technician's ability to perform seven standard ASTM field tests on freshly mixed concrete: sampling (C172), slump (C143), temperature (C1064), density/unit weight/yield (C138), air content by pressure method (C231), air content by volumetric method (C173), and making and curing concrete test specimens in the field (C31). It is the most widely held ACI certification and is required by the International Building Code (IBC) and ACI 318 for technicians performing acceptance testing of structural concrete.

Assessment

Written exam (55 multiple-choice questions, 1 hour, closed book) plus a pass/fail performance exam on all seven ASTM field tests

Time Limit

1 hour (written) + performance exam (separate)

Passing Score

60% on each ASTM test method AND 70% overall on the written exam, plus passing the performance exam

Exam Fee

$610 ACI/SCC members, $660 non-members (pre-July 2026); $620/$670 from July 2026 (American Concrete Institute (ACI))

ACI Field Testing I Exam Content Outline

15%

ASTM C172 Sampling Freshly Mixed Concrete

Composite sampling from stationary and truck mixers, sample size, remixing, protection, and the 15-minute and 5-minute time limits.

18%

ASTM C143 Slump Test

Slump cone dimensions, 3-layer 25-stroke rodding, 5 plus or minus 2 second lift in 12 inches, slump measurement, shearing, and 2-1/2 minute time limit.

18%

ASTM C231 Pressure Air Meter (Type B)

Type B pressure meter operation, 3 layers of 25 rod strokes, 10-15 mallet taps, aggregate correction factor, and petcock water injection.

13%

ASTM C173 Volumetric Air Meter

Rollameter procedure, 2 layers of 25 rod strokes, isopropyl alcohol correction, rolling to 0.25% agreement, and use with lightweight aggregate.

15%

ASTM C138 Density, Yield, and Gravimetric Air Content

Unit weight measurement, measure calibration, yield and relative yield calculations, and gravimetric air content as a cross-check.

ASTM C1064 Temperature

Sensor accuracy, 3-inch minimum concrete coverage, 2 to 5 minute stabilization, 5-minute time limit, and ACI 305/306 temperature limits.

13%

ASTM C31 Making and Curing Field Specimens

6x12 and 4x8 cylinder sizes, rodding (25 strokes per layer), initial curing at 60-80 F, 24 plus or minus 8 hour demolding, 4-hour transport to lab.

How to Pass the ACI Field Testing I Exam

What You Need to Know

Passing score: 60% on each ASTM test method AND 70% overall on the written exam, plus passing the performance exam
Assessment: Written exam (55 multiple-choice questions, 1 hour, closed book) plus a pass/fail performance exam on all seven ASTM field tests
Time limit: 1 hour (written) + performance exam (separate)
Exam fee: $610 ACI/SCC members, $660 non-members (pre-July 2026); $620/$670 from July 2026

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

ACI Field Testing I Study Tips from Top Performers

1Memorize the slump test sequence exactly: 3 layers, 25 rod strokes per layer with 5/8 inch rod, penetrate 1 inch into the layer below, 10-15 mallet taps are NOT part of C143 (that is C231/C138), lift cone 12 inches in 5 plus or minus 2 seconds, complete entire test within 2-1/2 minutes.

2Know which method to use when: ASTM C231 pressure method does NOT work for lightweight or porous aggregates. Use ASTM C173 volumetric (rollameter) instead for those concretes.

3Memorize C138 rodding rules: smaller measures (0.2 to 0.4 ft^3) use 2 layers with 25 strokes each; larger measures (0.5 to 1.0 ft^3) use 3 layers with 50 strokes each.

4Know ASTM C31 cylinder rules cold: 6x12 in. cylinders use 3 layers with 25 rod strokes (5/8 in. rod); 4x8 in. cylinders use 2 layers with 25 rod strokes (3/8 in. rod). Max aggregate = 1/3 of cylinder diameter.

5Initial curing temperature for C31: 60-80 F for concrete below 6000 psi, 68-78 F for 6000 psi and above, not to exceed 48 hours before demolding.

6ASTM C1064 temperature: 3-inch minimum concrete around the sensor in all directions, 2 to 5 minute stabilization, reading to plus or minus 1 degree F, verified at least annually.

7ASTM C172 time limits: 15 minutes max between first and last portion of composite sample, 5 minutes max to start slump/air/temperature tests, 15 minutes max to begin molding strength specimens.

8Practice the seven performance tests physically. The written exam is only half the battle. Attend a chapter-sponsored hands-on session before exam day.

Frequently Asked Questions

What is the ACI Concrete Field Testing Technician Grade I certification?

It is the most widely held ACI certification and validates that a technician can perform the seven standard ASTM field tests on freshly mixed concrete: sampling (C172), slump (C143), temperature (C1064), density/unit weight/yield (C138), pressure air content (C231), volumetric air content (C173), and making and curing specimens (C31). The IBC and ACI 318 require Grade I certified technicians to perform acceptance testing of structural concrete on most building projects.

How much does the ACI Grade I exam cost in 2026?

Through June 2026, ACI chapter pricing is typically $610 for ACI/SCC (Strategic Capture Center) members and $660 for non-members. Starting July 2026, the fee increases to approximately $620 for members and $670 for non-members. Some chapters and training providers bundle the exam with a preparation class for $625 or more. Pricing varies by chapter, so check with your local ACI sponsoring group.

How many questions are on the ACI Grade I written exam and how long is it?

The written exam is a 1-hour, closed-book test with 55 multiple-choice questions. The questions are distributed across the seven ASTM test methods, with approximately 5 to 10 questions per method. You must also complete a separate hands-on performance exam in which an ACI examiner observes you perform each of the seven tests.

What is the passing score for the ACI Grade I exam?

The written exam has a dual passing requirement. You must score at least 60% correct on each individual ASTM test method AND achieve at least 70% overall. A high overall score cannot compensate for scoring below 60% on any one test method. You must also pass the performance exam by demonstrating proficiency on all seven ASTM procedures, scored pass/fail by the examiner.

Are there any prerequisites for the ACI Grade I exam?

No. There are no formal prerequisites for the Grade I certification. You do not need prior experience, a degree, or ACI membership to sit for the exam. However, ACI strongly recommends studying the CP-1 Technician Workbook and the current editions of the seven ASTM standards, and completing a preparation class offered by your local ACI chapter or other training provider.

How long is the ACI Grade I certification valid?

ACI Grade I certification is valid for 5 years. To renew, you must either retake the written and performance exams or, where ACI policy allows, recertify through continued field activity. The 5-year term ensures certified technicians remain current with ASTM standard updates, which are regularly revised.

How long should I study for the ACI Grade I exam?

Most candidates study 20 to 40 hours over 2 to 6 weeks. Focus on memorizing the specific numerical values in each ASTM standard: 25 rod strokes per slump layer, 10-15 mallet taps, 5 plus or minus 2 seconds to lift the slump cone 12 inches, 2-1/2 minute slump time limit, 15-minute composite sample window, 5-minute test start window, 3-inch minimum thermometer coverage, 60-80 degrees F initial curing, and 24 plus or minus 8 hour demolding. Practice the performance exam hands-on at your training chapter.

What are the seven ASTM tests covered on the ACI Grade I exam?

The seven required ASTM standards are: (1) C172 Sampling Freshly Mixed Concrete, (2) C143 Slump of Hydraulic-Cement Concrete, (3) C1064 Temperature of Freshly Mixed Concrete, (4) C138 Density (Unit Weight), Yield, and Air Content (Gravimetric), (5) C231 Air Content of Freshly Mixed Concrete by the Pressure Method, (6) C173 Air Content of Freshly Mixed Concrete by the Volumetric Method, and (7) C31 Making and Curing Concrete Test Specimens in the Field. You must know each standard's procedure and numerical tolerances in detail.