NT Build 492 provides data for durable concrete
NT Build 492 is a test that determines the diffusion coefficient of concrete. Diffusion is the movement of a dissolved substance under a concentration gradient. That is, ions in solution […]
Testing
Can you get a representative sample of concrete?
A representative sample of anything is an unbiased selection from the whole population. It’s a statistical concept that applies to everything from opinion polls to laboratory testing. In principle it […]
Make sure you take good concrete cores
We often receive concrete cores from our clients for petrography or other types of testing. When we haven’t witnessed the coring, we can’t always tell whether a core represents damaged […]
Synopsis: Who is Watching Out for the Concrete Cylinders?
A recent paper in Concrete International recommends changes to the relevant ACI and ASTM specifications as well as the AIA MasterSpec to ensure that concrete cylinders get the appropriate curing. […]
Volumetric and Hardened Air Contents the Same
Air entrained concrete is still the biggest headache in concrete production. We have recently been discussing comparisons between the pressure meter and the microscope. It may seem counterintuitive, but the […]
Rating the suitability of local aggregates
You don’t usually think of gravel or aggregates as a resource until you’re trying to make concrete. In many parts of the country, good-quality aggregates for concrete are in short […]