Soils Testing Technician

The Soils Testing Technician course covers laboratory and field tests related to earthwork, with particular emphasis on soil classification, plasticity index, moisture-density relationships, and nuclear density.

Pre-Requisite Requirements

The Basic Aggregates Testing Technician course is a required pre-requisite for the Soils Testing Technician course.  This course is not intended to provide basic training, but rather to serve as a refresher and evaluation leading to certification.  Prior to attending the course, participants should have a working knowledge of soil testing methods, as well as the mathematical calculations associated with those methods.  Experience in physically performing these test methods is strongly recommended. 

Soils Review Materials

Specifications

The procedures covered in this course are those prescribed by the Arkansas Department of Transportation (ARDOT) Standard Specifications for Highway Construction and related specifications, including:

  • AASHTO T 89 Determining the Liquid Limit of Soils
  • AASHTO T 90 Determining the Plastic Limit and Plasticity Index of Soils
  • AASHTO T 99 Moisture-Density Relations of Soils Using a 2.5-kg (5.5-lb) Rammer and a 305-mm (12-in.) Drop
  • AASHTO T 180 Moisture-Density Relations of Soils Using 4.54kg(10lb.) Rammer and a 457mm(18in.) Drop
  • AASHTO T 217 Determination of Moisture in Soils by Means of a Calcium Carbide Gas Pressure Moisture Tester
  • AASHTO T 265 Laboratory Determination of Moisture Content of Soils
  • AASHTO T 310 In-Place Density and Moisture Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)
  • AASHTO M 145 Classification of Soils and Soil-Aggregates Mixtures for Highway Construction Purposes
  • AASHTO M 146 Terms Relating to Subgrade, Soil-Aggregate, and Fill Materials
  • AASHTO R 58 Dry Preparation of Disturbed Soil and Soil Aggregate Samples for Test
  • ARDOT 30 Sampling Soils
  • ARDOT 347 Determining Moisture Content by Speedy Moisture Content Tester
  • ARDOT 348 Moisture Content of Soils or Aggregates

Supplies and Equipment

All necessary equipment and supplies used in the Soils Testing Technician course will be furnished by CTTP.  A course notebook and pencil is provided to each participant.  Calculators may be borrowed from CTTP; however, students are often more comfortable bringing a calculator with which they are familiar, and routinely use.  Other items that may be useful include a straightedge or ruler, pen, pencil, and highlighter.

CTTP course participants are required to wear applicable personal protective equipment in the laboratory, including long pants, closed-toe shoes, and safety glasses.  Safety glasses, gloves, and other personal protective equipment may be borrowed from CTTP during the class.

Course Schedule

Each Soils Testing course will begin at 1:00 pm on Day 1 unless otherwise stated, with check-in and registration from 12:30 pm to 1:00 pm.  Classroom and laboratory instruction will be provided on Day 1 and Day 2.  Written and performance exams will be given on Day 3, with the course concluding no later than 4:00 pm on Day 3.  More information can be found in the Detailed Course Schedule.

Exams

The Soils Testing Technician certification requires each participant to pass both a written and a performance exam.  The written exam is closed-book, and subject to a two-hour time limit.  In order to receive certification, 70% of all questions must be answered correctly on the written portion of the exam.

Performance exams must be performed individually, and are graded on a “pass/fail” basis.  Participants must perform all methods correctly in order to pass the performance portion of the course.  Two attempts are allowed at each station. The Soils Testing performance exam consists of three stations, including:

  • AASHTO T 89/90: Determining Liquid Limit of Soils and Determining the Plastic Limit and Plasticity Index of Soils
  • AASHTO T 99: Moisture-Density Relations of Soils Using a 2.5-kg (5.5-lb) Rammer and a 305-mm (12-in.) Drop
  • AASHTO T 310: In-Place Density and Moisture Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)

Participants who do not pass the Soils Testing Technician course by failure of either the written or performance exam will be required to repeat the entire course.

Certification

Upon successful completion of both the written and performance exams, participants will receive a five-year certification in Soils Testing from CTTP.  Certified individuals will receive a CTTP certificate and pocket card, and will be added to the CTTP website list of Certified Technicians.  Expiration dates occur on a semi-annual basis, and will be either June 30 or December 31 after the five-year certification period.

Recertification in Soils may be achieved by successful completion of the standard 2 ½ day Soils Testing Technician course.