Aggregate Base Testing Technician

2026 Aggregate Base Scheduling Changes:

Shared Sessions
In an effort to maximize our available space, to more efficiently utilize our Supplemental Examiners, and to better accommodate testing needs, all ACI Aggregate Base exam sessions will occur in tandem with other exams. These sessions will be referred to as Advanced Lab sessions and will have a shared capacity across four (4) exams: Aggregate Level 2 (Agg 2), Aggregate Base (Agg Base), Laboratory Level 2 (Lab 2), and Self-Consolidating Concrete (SCC). Examinees will be allowed to register for up to 2 different exams on the same date if desired.

2026 Advanced Lab Dates [Not Yet Open for Registration]:

*This is the anticipated schedule for 2026. There is a possibility that some dates or locations could change as we finalize this schedule and finish securing locations.*

Scope and Knowledge:

This program requires demonstration of the knowledge covered on the Job Task Analysis (JTA): JTA for ACI Aggregate Base Testing Technician Certification. The JTA is a detailed list of specific points of knowledge that may be included in the examinations for this ACI Certification program. ACI urges candidates to use the JTA to prepare for the certification exams.

The program requires a working knowledge of the following AASHTO and/or ASTM standards:

• AASHTO R 90/ASTM D75—Sampling Aggregates
• AASHTO T 248/ASTM C702—Reducing Samples of Aggregate to Testing Size
• AASHTO R 58/ASTM D421*—Dry Preparation of Disturbed Soil and Soil-Aggregate Samples for Test
• AASHTO T 89/ASTM D4318—Determining the Liquid Limits of Soils
• AASHTO T 90/D4318—Determining the Plastic Limit and Plasticity Index of Soils
• AASHTO T 88/ASTM D422—Particle Size Analysis of Soils
• AASHTO T 265/ASTM D2216—Laboratory Determination of Moisture Content of Soils
• AASHTO T 180/ASTM D1557—Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm (18-in.) Drop
• AASHTO T 99/ASTM D698—Moisture-Density Relations of Soils Using a 2.5-kg (5.5-lb) Rammer and a 305-mm (12-in.) Drop

*Written exam only.

Certification Requirements:

ACI will grant certification only to those applicants who meet both of the following requirements:

1. A passing grade on the ACI written examination, and
2. Successful completion of the ACI performance examination.

The two-hour written examination is open-book and consists of approximately 100 multiple-choice questions. There are 8 to 12 questions on each of the standards.

To pass the written examination, both of the following conditions must be met:

1. At least 60% correct for each of the required standards, and
2. A minimum score of 70% overall.

The performance examination is closed-book and requires actual demonstration of the required standards. The examinee is judged on his/her ability to correctly perform or describe all of the required procedures for each standard.

Certification is valid for a period of five years from the date of successfully completing all requirements. Recertification requires successful completion of both the written and performance examinations.