Evaluating aggregates using ASTM C1778
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 […]
Specifications
ASTM C1074 predicts the strength of concrete in place
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 […]
Finishing air-entrained concrete requires a light touch
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 […]
Specifying tests for durable concrete
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 for slabs on ground
Although engineers usually think of compressive strength as the most important property of concrete, concrete for slabs on ground is different. According to ACI 302, for slabs on ground the […]
Preventing aggregate popouts
In Minnesota, Iowa, and South Dakota, we sometimes see aggregate popouts, particularly in concrete flatwork. Popouts are unsightly surface defects that may appear a few hours to a few weeks […]
What you need to know about CALGreen
The 2019 edition of the California Green Building Standards Code, also known as CALGreen, took effect at the beginning of this year. Its goals include: reducing greenhouse gas emissions from […]
Floor flatness and levelness
Floor flatness and levelness matter in such applications as manufacturing facilities, big box stores, and warehouses. ACI 117.1R-14 defines floor flatness (Ff) as “deviation of a surface from a plane” […]
Thermal control plans for mass concrete
Specifications for mass concrete require thermal control plans to minimize cracking. Traditionally, mass concrete meant dams. But other structures may be large enough—or have enough portland cement—to treat as mass […]
New product innovation Q & A
Q: I’M INTERESTED IN DEVELOPING A NEW CEMENTITIOUS PRODUCT BUT NEED HELP FIGURING OUT A FORMULATION TO MEET THE SPECIFICATIONS. IS THIS SOMETHING BETON HAS EXPERIENCE WITH? A: The products […]