Why do scientists keep changing their minds?
One reason vaccine holdouts give for not trusting authorities such as the Centers for Disease Control is that these scientists are constantly changing their minds. At first they recommended that […]
One reason vaccine holdouts give for not trusting authorities such as the Centers for Disease Control is that these scientists are constantly changing their minds. At first they recommended that […]
ASTM C1778, “Standard Guide for Reducing the Risk of Deleterious Alkali-Aggregate Reaction in Concrete,” can help you decide how best to mitigate expansions due to reactive aggregates. It covers both […]
Despite our need for durability and high performance, the most common design criterion for concrete is compressive strength. Usually we specify the 28-day strength, that is, the compressive strength after […]
Malaria, a debilitating and sometimes fatal mosquito-borne illness, has been the object of many prevention efforts. Most of them focus on the vectors, various species of the Anopheles mosquito. To […]
When finishing air-entrained concrete, less is more. Hard-troweled surfaces and air-entrained concrete don’t mix. If you need to entrain air—that is, if the concrete will experience cycles of freezing and […]
We’ve all seen arrays of solar panels on rooftops. They convert the sun’s energy into electricity, lowering the homeowner’s electric bill—and maybe even adding power to the grid. On a […]
Now that things are opening up again, I’m looking forward to traveling. One thing that interests me is local architecture, especially traditional architecture. Sometimes we can be rather snobbish about […]
Throughout my career, our industry has been pursuing performance specifications for concrete. That is, we want specifications for what the concrete must do, not what it must be. The sticking […]
Concrete in certain environments is subject to sulfate attack. These include seawater, some industrial environments, sanitary sewers, and sulfate-bearing soils and groundwater. As engineers have known since the early 1900s, […]
Part of professional engineering practice is objective communication. In fact, it’s so important that the Engineers’ Code of Ethics calls it out specifically. How do we achieve objectivity in technical […]