ACI-AGGREGATE-BASE Pass Rate 2026: What the Data Shows

Why There's No Public Pass Rate for This Credential

If you searched for "ACI-AGGREGATE-BASE pass rate 2026" hoping for a clean percentage, you're going to be disappointed - and that's worth explaining rather than papering over. The American Concrete Institute (ACI) does not publish aggregate pass/fail statistics for Aggregate Base Testing Technician-ASTM Methods. There's no dashboard, no annual report, no leaked internal number. Any blog post that quotes a specific pass rate for this credential is either guessing or, more likely, importing a figure from an unrelated program that happens to share the same acronym.

That distinction matters because ACI-AGGREGATE-BASE has been used to label more than one credential over the years, including a now-retired combined-methods Aggregate Base program. This article covers only the currently active ASTM Methods track. If a source cites exam fees, domain weights, or salary numbers that don't match what's described here, it's likely describing something else entirely.

What "Passing" Actually Requires

The written examination for Aggregate Base Testing Technician-ASTM Methods is open-book, meaning you can reference ACI-approved materials during the test, but it's still timed at two hours and covers approximately 75 multiple-choice questions. The scoring rule is the part candidates most often underestimate:

• You need at least 60% within every required standard section individually.
• You also need at least 70% overall across the full exam.

This dual threshold means you can't coast on strong sections to cover for a weak one. Score 90% on four domains and 40% on a fifth, and you fail - even if your overall average clears 70%. This is the single biggest structural reason a candidate might "fail" despite feeling generally prepared: one neglected standard sinks the entire attempt. For a section-by-section breakdown of exactly what this scoring model demands, see our ACI-AGGREGATE-BASE Passing Score guide.

The performance exam works differently. It's closed-book and requires successful, hands-on demonstration of every required procedure, with verbal descriptions permitted only where the official checklists allow it. There's no partial credit for "mostly" performing a test method correctly - the checklist format is binary per required step.

Two Exams, One Deadline: How Structure Shapes Outcomes

Aggregate Base Testing Technician-ASTM Methods isn't a single test - it's two components, written and performance, and both must be passed within one year of each other. This creates a scheduling risk that has nothing to do with content knowledge: if you pass the written exam in January but can't arrange a performance evaluation before the following January, your written pass expires and you have to retake it.

Approved simple-function, nonprogrammable calculators are allowed for the written portion; a phone calculator app is not acceptable, so confirm your device meets the requirement before test day rather than discovering it at check-in.

The Seven ASTM Domains and Where Points Get Lost

The exam content maps directly to seven ASTM standard sections. These are the official domains - not an equal-weight split - and each carries its own 60% minimum threshold, so no domain is "safe to skip."

Domains 6 and 7 are the pair candidates most often mix up, since the procedures are structurally similar but differ in effort, mold selection, and layer/blow counts. For a fuller walkthrough of all seven areas and how they interrelate, see the complete guide to all 7 content areas.

Retesting: What Happens If You Fail a Component

If you fail either the written or the performance component, the retest covers the entire failed exam - not just the individual standard sections you missed. Fail Domain 4 and Domain 6 on the written test, and your retest is the full ~75-question exam again, not a targeted 15-question makeup. This is another reason the 60%/70% dual threshold deserves early attention: a narrow miss in one domain forces a complete re-sit of the whole component.

Who Sits This Exam - and Why That Matters

Aggregate Base Testing Technician-ASTM Methods is aimed at technicians performing field and laboratory testing on base, subbase, and subgrade materials for highway, site development, and geotechnical work where ASTM procedures govern acceptance testing. Employers in this space include materials testing labs, DOT-adjacent contractors, and geotechnical firms that need documented proof a technician can run the sampling, reduction, moisture, plasticity, gradation, and compaction procedures listed above without supervision.

Because the exam is administered by approved sponsoring groups with ACI examiners and proctors, and graded by ACI, the credential functions as portable proof of competency across employers rather than an internal, single-company qualification. If you're trying to understand how this fits into a broader career path, our overview of ACI-AGGREGATE-BASE jobs and the ROI analysis go deeper into where this certification is actually used.

Pathways That Change Your Starting Position

Not every candidate starts from zero, and this affects how the "difficulty" of passing actually plays out for you individually:

• Current AASHTO Methods holders: If you already hold the Aggregate Base Testing Technician-AASHTO credential, you can earn the ASTM credential by passing only the ASTM written examination, provided you do so within one year of obtaining the AASHTO certification. This skips a full standalone certification cycle.
• Aggregate Testing Technician-Level 1 holders: Current Level 1 holders may receive specified performance-procedure exemptions, reducing the hands-on demonstration burden for procedures already validated under that credential.

These pathways don't change the written scoring thresholds, but they do change how much new material you need to master before attempting the exam. Full eligibility details, including base prerequisites, are covered in ACI-AGGREGATE-BASE Requirements 2026.

Building a Study Plan Around the Real Risk Areas

Given the dual scoring threshold and the all-or-nothing retest rule, the smartest prep sequencing isn't "study everything equally" - it's "identify which of the seven domains you're weakest in, and front-load those." A rough four-week structure built around that logic:

Spacing your compaction-domain review across two separate sessions (rather than cramming D1557 and D698 back-to-back) helps prevent the mold-size, layer-count, and blow-count details from blending together - a common source of avoidable errors on both the written and performance components. For a more detailed, week-by-week breakdown, see the ACI-AGGREGATE-BASE Study Guide, and pair your review with realistic practice questions on our practice test platform to get comfortable with the multiple-choice format before exam day.

Written vs. Performance: A Side-by-Side Look

Understanding this split matters more than chasing an unpublished pass-rate number. The written exam rewards broad, section-by-section command of all seven ASTM standards; the performance exam rewards procedural muscle memory under checklist scrutiny. Struggling candidates typically underestimate one or the other rather than both. If cost planning factors into your timeline - since the CP-46 workbook itself runs $133 non-member/$69 member as of a September 10, 2026 check - our certification cost breakdown separates workbook pricing from examination administration so you can budget accurately.

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