100+ Free ACI CLTT-2 Practice Questions
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Per ASTM C78 (flexural strength of concrete using third-point loading), the rate of loading is expressed as:
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Key Facts: ACI CLTT-2 Exam
~75
MC Questions (Written)
ACI CLTT-2 Program
2 hours
Written Exam Time
ACI CLTT-2 Program
≥70% / ≥60%
Overall and Per-Standard Minimum
ACI CLTT-2 Program
C192 + C157
Performance Exam Standards
ACI CLTT-2 Program
5 years
Certification Validity
ACI
$300-$500
Typical Exam Fee
ACI sponsoring groups
ACI CLTT-2 is the Level 2 concrete laboratory technician certification from the American Concrete Institute. The written exam is open-book, ~75 multiple-choice questions in 2 hours, requires ≥70% overall and ≥60% on each required ASTM, and is paired with a closed-book performance exam on ASTM C192 (making and curing) and C157 (length change). Candidates must hold a current CLTT-Level 1 certificate and document at least 2,000 hours of approved laboratory experience. Certification is valid 5 years and fees typically run $300-$500 through ACI local sponsoring groups.
Sample ACI CLTT-2 Practice Questions
Try these sample questions to test your ACI CLTT-2 exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1Per ASTM C192/C192M, what is the number of rod strokes required per layer when consolidating a standard 150 x 300 mm (6 x 12 in.) concrete cylinder by rodding?
2According to ASTM C192/C192M, how is the method of consolidation (rodding vs vibration) selected when not specified by the project?
3ASTM C192/C192M requires initial curing of molded specimens for the first 24 hours at what temperature range?
4Per ASTM C192/C192M, what temperature is required for the moist room or water tank used for final curing of strength-test specimens?
5Per ASTM C192/C192M, after a 0.028 m³ (1 ft³) drum batch is mixed, what is the minimum allowed mixing time after all ingredients are in the mixer?
6When using internal vibration to consolidate a 150 mm (6 in.) diameter cylinder per ASTM C192, how many insertions per layer are required, and how many layers should the cylinder be filled in?
7Per ASTM C192/C192M, what is the maximum permissible elapsed time between completing mixing of a batch and starting molding of strength specimens?
8ASTM C192 requires the tamping rod for a standard 150 mm cylinder to have what diameter and tip configuration?
9Per ASTM C192, beams for flexural strength testing 150 x 150 x 530 mm (6 x 6 x 21 in.) consolidated by rodding require how many strokes per layer and how many layers?
10After molding cylinders per ASTM C192, what is the standard tolerance window for demolding the specimens?
About the ACI CLTT-2 Exam
ACI CLTT-2 is the second-tier ACI laboratory technician credential for staff who run hardened-concrete strength, drilled-core, splitting-tensile, and drying-shrinkage tests in a commercial concrete testing laboratory. Candidates must already hold the CLTT-Level 1 certificate and have at least 2,000 hours of approved lab experience. The certification consists of an open-book ~75-question written exam (2 hours) and a closed-book performance exam demonstrating ASTM C192 and C157 step-by-step.
Questions
75 scored questions
Time Limit
2 hours written + performance
Passing Score
≥70% written and ≥60% per ASTM + pass performance
Exam Fee
$300-$500 (varies by sponsoring group) (American Concrete Institute (ACI) via local sponsoring groups)
ACI CLTT-2 Exam Content Outline
ASTM C192 — Making and Curing Concrete Test Specimens in the Laboratory
Sample handling, batching, mixing, mold filling in layers, rodding (25 strokes per layer for standard cylinders) versus internal/external vibration based on slump, finishing, initial curing 16-32 h at 16-27 °C, and final moist curing at 23.0 ± 2.0 °C with free water on all surfaces.
ASTM C157 — Length Change of Hardened Hydraulic-Cement Mortar and Concrete
Casting 75x75x285 mm or 100x100x285 mm prisms with cast-in studs, initial cure 23.5 ± 0.5 h in molds, 30-minute lime-saturated bath, initial comparator reading, drying-room storage at 23.0 ± 2.0 °C and 50 ± 4% RH, and comparator readings at 4, 7, 14, 28 days and 8, 16, 32, 64 weeks.
ASTM C42 — Obtaining and Testing Drilled Cores and Sawed Beams
Core diameter requirements (≥2x NMSA), core moisture conditioning, length-to-diameter correction factors (0.98 at L/D 1.75, 0.96 at 1.50, 0.93 at 1.25, 0.87 at 1.00), allowable timing for testing after coring, and reporting requirements.
ASTM C496 — Splitting Tensile Strength
Plywood bearing strips approximately 25 mm wide by 3 mm thick, applying continuous load at 689-1380 kPa/min (100-200 psi/min) splitting tensile stress, alignment of diametral plane, and calculation T = 2P/(π L D).
ASTM C39 and Companion Strength Standards
Cylinder end-plane tolerance 0.5°, load rate 0.25 ± 0.05 MPa/s (35 ± 7 psi/s) applied continuously without shock, capping per C617 or grinding per C1231, six standard fracture patterns, and machine verification per C39 §5.
Aggregate Laboratory Tests for Mix Design
Dry-rodded bulk density per ASTM C29, specific gravity and absorption of coarse aggregate (C127) and fine aggregate (C128), and total moisture content by drying per C566, all required as inputs to ACI 211.1 absolute-volume mix design.
ACI 211.1 — Standard Practice for Selecting Concrete Mix Proportions
Nine-step absolute-volume method: slump, NMSA, water content, w/cm ratio for strength and exposure, cement content, coarse aggregate volume from FM and NMSA, fine aggregate by absolute volume balance, yield check, and aggregate moisture corrections.
ACI 214R — Statistical Evaluation of Strength Tests
Within-test versus batch-to-batch standard deviation, coefficient of variation, required average strength fcr' equations, minimum 30-test record requirement, and standards-of-control categories for general construction concrete.
How to Pass the ACI CLTT-2 Exam
What You Need to Know
- Passing score: ≥70% written and ≥60% per ASTM + pass performance
- Exam length: 75 questions
- Time limit: 2 hours written + performance
- Exam fee: $300-$500 (varies by sponsoring group)
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 CLTT-2 Study Tips from Top Performers
Frequently Asked Questions
What is the ACI CLTT-Level 2 certification?
ACI CLTT-Level 2 (Concrete Laboratory Testing Technician — Level 2) is the second-tier laboratory technician certification from the American Concrete Institute. It validates a technician's ability to perform compressive strength, splitting tensile, length-change (drying shrinkage), and drilled-core testing on hardened concrete, plus laboratory specimen molding per ASTM C192. The credential is required by many state DOTs and ASTM C1077 reference laboratories for senior lab staff.
What ASTM standards and ACI documents are on the CLTT-2 written exam?
The required documents include ASTM C192/C192M, ASTM C157/C157M, ASTM C42/C42M, and ASTM C496/C496M, along with ACI 211.1 Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete and ACI 214R Guide to Evaluation of Strength Test Results of Concrete. Related ASTM standards referenced within these documents — C29, C39, C78, C127, C128, C566, C617, and C1231 — also appear on the exam.
How is the ACI CLTT-2 written exam scored?
Two conditions must both be met to pass: at least 60% correct on each of the required ASTM and ACI documents, and a minimum 70% overall score. Each document section typically contains 8-12 multiple-choice questions out of approximately 75 total. Falling below 60% on a single document results in a fail even if the overall score is above 70%.
What is the performance exam for CLTT-2?
The performance exam is closed-book and requires the candidate to demonstrate ASTM C192 (making and curing concrete cylinders or beams in the laboratory) and ASTM C157 (preparing and reading length-change specimens). Examiners observe each step and judge whether the candidate correctly performs every required procedure. Performance failures must be re-demonstrated; both the written and performance portions must be passed.
What are the prerequisites for ACI CLTT-2?
Candidates must hold a current ACI Concrete Laboratory Testing Technician — Level 1 (CLTT-Level 1) certification and have at least one year (≥2,000 hours) of approved concrete laboratory experience. Up to half of the experience requirement can be substituted by completion of 60 or more college credit hours in an approved engineering or construction program.
How much does the ACI CLTT-2 exam cost and how long is it valid?
Fees are set by each ACI local sponsoring group and typically range from $300 to $500 including both the written and performance portions. Certification is valid for 5 years and recertification requires retaking both the written and performance exams. Required references including ASTM standards and ACI 211.1 / 214R are extra and add roughly $150-$250 if purchased new.