ACI-AGGREGATE-BASE Passing Score 2026: Exactly What You Need to Pass

How the ACI-AGGREGATE-BASE Passing Score Actually Works

The Aggregate Base Testing Technician-ASTM Methods credential, administered by the American Concrete Institute (ACI) through approved sponsoring groups and ACI examiners/proctors, does not use a single composite score the way many multiple-choice certifications do. Instead, ACI applies a dual-threshold rule to the written exam and a separate demonstration standard to the performance exam. Understanding this structure matters more than memorizing a single "magic number," because a candidate can technically score well above 70% overall and still fail the exam if one required section falls below 60%.

If you're still getting oriented to the credential itself, it helps to start with the complete guide to all seven ASTM content areas before diving into scoring mechanics, since the passing rule is applied section-by-section against those exact domains.

Written Exam Scoring: 60% Per Section, 70% Overall

The written examination is open-book, meaning you're permitted to use ACI-approved references during testing, and it runs on a strict two-hour clock. It contains approximately 75 multiple-choice questions pulled from the seven official ASTM standard sections that make up the job-task analysis. That volume of questions across seven distinct standards means pacing matters: with roughly 75 questions in 120 minutes, you have well under two minutes per question on average, and some questions involving calculation or interpretation of test data will take longer than simple recall items.

The scoring rule has two parts working together:

• Section minimum: At least 60% correct within each individual required standard section (D75/D75M, C702/C702M, D4318, D7928, D2216, D1557, and D698).
• Overall minimum: At least 70% correct across the exam as a whole.

This means a candidate cannot "coast" on strong performance in one or two familiar domains while neglecting a section they find unfamiliar. Someone who tests very well on moisture content (D2216) and compaction effort (D698 and D1557) but badly under-prepares for the hydrometer analysis in D7928 can still fail outright if that section drops below the 60% floor - regardless of how high the overall percentage lands. For a deeper breakdown of why this section-by-section structure catches unprepared candidates, see the analysis in how hard the ACI-AGGREGATE-BASE exam really is.

Performance Exam: Checklist-Based Pass/Fail

Unlike the written exam's percentage thresholds, the performance examination is closed-book and evaluated against procedural checklists tied to the same ASTM standards. There isn't a partial-credit percentage to hit - you must successfully demonstrate all required procedures as specified. Where checklists explicitly permit it, a verbal description of a step can substitute for a physical demonstration, but this is limited to the specific items the checklist allows, not a general substitute for hands-on skill.

Practically, this means the performance component rewards muscle memory and correct sequencing more than raw knowledge. A candidate who can recite the moisture-content calculation from D2216 perfectly on the written exam but fumbles the balance zeroing, drying, or mass-recording sequence during the hands-on demonstration can still fail the performance component. The two exams test different competencies, and passing one does not predict passing the other.

The Seven ASTM Domains and Your Score

Because the written exam's passing rule is applied at the section level, it's worth treating each of the seven domains as its own mini-exam rather than one undifferentiated pool of 75 questions. ACI's official domain list - the seven ASTM standard sections - is not weighted equally; it reflects the standards themselves rather than a fixed percentage allocation per section.

• Domain 1 - ASTM D75/D75M: Standard Practice for Sampling Aggregates
• Domain 2 - ASTM C702/C702M: Standard Practice for Reducing Samples of Aggregate to Testing Size
• Domain 3 - ASTM D4318: Liquid Limit, Plastic Limit, and Plasticity Index of Soils
• Domain 4 - ASTM D7928: Particle-Size Distribution (Gradation) of Fine-Grained Soils Using Sedimentation (Hydrometer) Analysis
• Domain 5 - ASTM D2216: Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• Domain 6 - ASTM D1557: Laboratory Compaction Characteristics Using Modified Effort
• Domain 7 - ASTM D698: Laboratory Compaction Characteristics Using Standard Effort

Because each of these seven sections carries its own 60% floor, candidates should self-assess weak sections early rather than discover them on exam day. The one-page review of must-know facts is a useful way to spot-check recall across all seven before committing to a full study plan, and the first-attempt study guide walks through how to sequence review of each standard.

What Happens If You Fail a Section - or the Whole Component

A common misconception is that failing one weak section on the written exam only requires restudying and retesting that single section. That is not how ACI structures the retest: a retest covers the entire failed examination component. If you fail the written exam because one of the seven sections dropped below 60% - even while every other section passed comfortably - you retest the full written exam, all approximately 75 questions, under the same two-hour open-book conditions. The same logic applies on the performance side: if you fail the demonstration of one required procedure, the retest addresses the performance component as a whole, not just that isolated task.

This retest structure raises the stakes of section-by-section preparation. It's far more efficient to shore up every domain before your first attempt than to treat any one ASTM standard as "good enough for now." If cost is a factor in how many attempts you can budget for, the certification cost breakdown is worth reviewing alongside your study plan - for reference, the CP-46 workbook itself is priced separately from examination fees (ACI listed it at $133 non-member/$69 member as of a September 10, 2026 check), so workbook cost and exam/retest cost are two different line items to budget for.

Calculators, References, and Other Score-Relevant Rules

A few procedural details affect whether you can even attempt every question, which indirectly affects your score:

• Approved calculators only: Simple-function, nonprogrammable calculators are permitted. Mobile devices cannot be used as calculators, even if you only intend to use the calculator app - bring a standalone approved unit.
• Open-book means ACI-approved references, not any material: The written exam is open-book, but only using references ACI has approved. The primary reference is CP-46 (first edition), the ASTM workbook - be sure you're studying from CP-46 and applying its applicable errata, not a similarly named AASHTO-track workbook (CP-47 belongs to the separate AASHTO Methods track and is not interchangeable with CP-46).
• Closed-book performance exam: No references during the hands-on demonstration, which is why procedural memorization (not just conceptual understanding) matters for that component.

Bringing the wrong calculator or the wrong reference edition doesn't just cost you time - it can functionally lower your score if you're forced to skip or guess on questions you'd otherwise answer correctly. Confirm your materials against current policy before exam day; requirements and eligibility mechanics are outlined in more detail in the eligibility and prerequisites guide.

The One-Year Window Between Components

Both the written and performance components must be passed within one year of each other. This means your passing score on the written exam has a shelf life relative to the performance exam, and vice versa. If you pass the written exam but delay scheduling the performance exam beyond that one-year window, your written pass may no longer count toward certification, and you could be required to retake it.

This timing rule creates a practical scheduling consideration: don't treat the two components as independent projects with unlimited runway between them. Plan your performance exam date as soon as you've scheduled or passed the written exam, not as an afterthought. Governing policy CPP 620.5-25 (approved February 14, 2025) sets the framework administered by ACI's approved sponsoring groups; the current ASTM job-task analysis behind the domain list was approved February 13, 2026, so the seven domains reflect the most current version of the standards being tested.

There are also pathway-specific timing rules worth knowing if you're transitioning credentials: a current AASHTO Methods holder can earn the ASTM credential by passing the ASTM written examination within one year of obtaining AASHTO certification, and current Aggregate Testing Technician-Level 1 holders may receive specified performance-procedure exemptions. If either applies to you, review the requirements page before assuming you need to sit for both components from scratch.

A Study Timeline Built Around the Scoring Rule

Because the written exam's 60%-per-section rule punishes uneven preparation, a sensible study sequence treats each ASTM standard as a checkpoint rather than lumping all seven into generic "exam review." A spaced-repetition approach works well here specifically because it forces you to revisit each of the seven sections more than once before test day, rather than studying each standard exactly once and moving on.

For a domain-by-domain breakdown of what each section actually tests, revisit the exam domains guide, and use practice questions on our practice test platform to simulate the section-by-section scoring pressure before your real attempt.

Written vs. Performance: Scoring at a Glance

Once you're comfortable with how scoring works, it's worth stepping back and asking whether the credential fits your career goals - the ROI analysis and earnings guide cover that angle, while the jobs overview looks at which employers in materials testing, geotechnical labs, and DOT-adjacent inspection work typically ask for this ASTM-track credential specifically.

Frequently Asked Questions