An Aggregate Base Testing Technician is an individual who has demonstrated the knowledge and ability to properly perform, record, and report the results of basic field and laboratory procedures for aggregates and soils.

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

• T 2/D75—Sampling Aggregates
• T 248/C702—Reducing Samples of Aggregate to Testing Size
• R 58/D421*—Dry Preparation of Disturbed Soil and Soil-Aggregate Samples for Test
• T 89/D4318—Determining the Liquid Limits of Soils
• T 90/D4318—Determining the Plastic Limit and Plasticity Index of Soils
• T 88/D422—Particle Size Analysis of Soils
• T 265/D2216—Laboratory Determination of Moisture Content of Soils
• T 180/D1557—Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm (18-in.) Drop
• T 99/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.

Recertification is necessary every five years and requires successful completion of both the written and performance examinations.

Study Material:

Go to the ACI Bookstore on this website to order and/or obtain current pricing on any items listed below:

CP–43(14): Technician Workbook for ACI Certification of Aggregate Base Testing Technician

This workbook contains information about the ACI Aggregate Base Testing Technician (ABTT) certification program, performance checklists, and reprints of all of the resource materials referenced by the certification examinations.

Program Policy:

Aggregate / Soils Base Testing Technician Policy