The construction materials testing (CMT) sector is an essential part of the construction industry. It focuses on ensuring structures have stable foundations.
Think about the Leaning Tower of Pisa… This bell tower is known for its nearly four-degree lean due to an unstable foundation!
CMT is all about ensuring structures are foundationally strong. It is one of the most crucial parts of any type of construction project, no matter the size.
So what does a CMT Technician do?
A CMT Technician completes a range of different tests on materials such as soil, aggregates, concrete, clay and asphalt.
There are two main types of roles in CMT:
Field Technicians who attend and complete testing on site.
Laboratory Technicians who complete testing in a laboratory.
A day in the life of a CMT Field Technician
Ben from CDR Geotechnical & Environmental Services performing a Dynamic Cone Penetrometer (DCP) test.
A CMT Field Technician starts their day early. Field testing CMT services take place on site, such as roadways, airports, utility projects and building developments.
The day begins with pre-starts or toolboxes; testers are equipped with testing information; it is then Field Technician’s responsibility to prepare vehicles with the required calibrated test equipment needed.
The Field Technician will liaise directly with clients to ensure that tests requirements are met. Testing is completed in accordance with specific Australian Standards or local state standards which outline the test types, testing procedures and equipment needed.
The Field Technician will complete tests, undertake correct documentation, and return the sufficient sample back to the laboratory.
A day in the life of a CMT Laboratory Technician
Dip and Mo from CDR Geotechnical & Environmental Services taking moistures.
A CMT Laboratory Technician starts their day by completing daily checks of the laboratory equipment for their serviceability and calibrations.
Laboratory Technicians work on the samples that have been obtained by their Field Technician colleagues or the samples delivered by their clients. The type of the tests is determined by the client’s requirements.
Laboratory Technicians prepare their workstations accordingly and undertake tests in accordance with Australian Standards, or the state methods based on the clients’ requests.
Types of tests
Soil testing
Soil sampling is one of the most critical aspect of testing soils and is carried out by CMT Technicians who are experienced and competent in a variety of sampling techniques and knowledge of soils. There are many different sampling methods for soils, these are dependent on the type of infrastructure build/construction that is to take place and clients requests. A few test types include:
Moisture content
CBR (California Bearing Ratio)
Permeability
Plasticity index
Particle size distribution
Compaction
Density and more.
Compaction testing
Soil compaction is the process in which stress is applied to a soil. When stress is applied to a soil this causes the soil to become dense. The purpose of this test is to identify optimum moisture content and maximum dry density. This test aim to identify how soils react compacted and how they will act as a foundation for a structure.
Concrete testing
Concrete samples tested for flexural strength, compression, workability, fluidity and more. A concrete slump test is completed by a Field Technician on site. It measures the consistency and workability of fresh concrete before it sets, therefore the ease with which concrete flows. It can also be used as an indicator of an improperly mixed batch.
Like soils, concrete samples casted in different moulds can be tested by the Laboratory Technician at the laboratory. Sometimes three similar samples casted from the same batch of concrete are tested in different time periods, such as 7, 14 and 28 days, which measures the strength of the dried and cured concrete.
Why are CMT Technicians important?
CMT Technicians are a critical part of a construction project. They ensure safety, stability, and longevity of projects they also determine the suitability of the construction materials for specific projects. They identify the quality of materials and highlight how these materials will react in the future. It is an essential part of a construction project and can inform engineering decisions.
Do you have what it takes to be a CMT Technician?
Analytical skills
Commitment to safety and quality
Can work autonomously as well as in a team
Ability to liaise and communicate with clients
Can-do attitude
Like a challenge!
If a CMT Technician sounds like the right career for you, a laboratory qualification can equip you with the skills and knowledge to get there.