Concrete “permeability” tests
For the most part, so-called concrete “permeability” tests measure something other than permeability. Permeability is the ease with which fluids can move through a porous material. That matters because most […]
For the most part, so-called concrete “permeability” tests measure something other than permeability. Permeability is the ease with which fluids can move through a porous material. That matters because most […]
When you submit a concrete sample for petrographic examination, how big a sample do you need? That is, what’s the appropriate concrete sample size? We’ve discussed in previous posts how […]
We often — mistakenly — refer to ASTM C1202, “Standard Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration,” as the Rapid Chloride Permeability test. Permeability […]
Many engineers have no idea how informative concrete petrography can be. That’s too bad, because concrete petrography is one of the most useful techniques in forensic engineering. Failure analysis of […]
ASTM C1709 provides a way to introduce alternative supplementary cementitious materials (ASCMs) into the marketplace. Supplementary cementitious materials include fly ash, slag cement, silica fume, and calcined clay. They can […]
ASTM C1556 is a test we use to assess the ability of concrete to resist the ingress of chloride ions. If we’re designing a high-performance concrete for a new parking […]
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 […]
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 […]
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 […]
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. […]