If you’re wondering “What is the ASTM C779 test?” – you’ve come to the right place.
At Intelligent Concrete, our team of concrete consultants, engineers, and scientists are constantly involved in concrete testing, including ASTM C779.
To help you better understand ASTM C779, let’s break down what it is, how it works, and why it’s used in the concrete industry.
What is the ASTM C779 test?
The ASTM C779 test is the standard testing method for the abrasion resistance of horizontal concrete surfaces. There are three different procedures to conduct the ASTM C779 test. At Intelligent Concrete, we prefer procedure C. Procedure C takes a concrete surface and places a 22-newton force over the head of a revolving drill at 1,000 rpm.
A uniquely constructed jig (with a hollow section that allows water to flow through it) allows 22 newton force to push down 8 steel balls going at 1000 RPM over the concrete surface.
What does the ASTM C779 test for?
ASTM C779 test is an accelerated method that helps you understand how concrete will respond to this abrasive force from steel balls.
Ultimately, the test is all based on your first line of defense – the cementitious coating. Results are dependent on the hardness of the aggregate, as well as the bond between the aggregate and hydrated cement matrix.
If you had a lot of dust on the aggregate or a very absorbent surface and subsurface, the interfacial zone that gives you that chemical and mechanical interlocking is going to be compromised. If that zone is compromised as those steel balls start rolling over the concrete (instead of grinding down the surface), they will start tearing out the aggregates. This will create little holes and singularities of stress occurring.
Why would you need an ASTM C779 test?
This test can help you avoid negative consequences in the real world. For example, concrete that doesn’t respond well to abrasive force can result in exposed aggregate. You can see this in the wheel wells of some highways.
With C779, you can determine how SCMs, cement paste, and aggregate can affect the resiliency to abrasive wear.
Interested in learning more about ASTM C779?
The Intelligent Concrete team frequently utilizes ASTM C779 to optimize concrete mixtures and formulations. We can help you develop and utilize stronger, longer lasting concrete.
If you’re interested in learning more about this or other concrete tests, give us a call or reach out to us online. We’d love to talk.