Frequently Asked Questions

In This Section

Other Sources for Answers

Search other resources on the ACI website for answers to technical questions

Technical Questions

ACI Committees, Membership, and Staff have answered common questions on a variety of concrete related topics.



Found 22 FAQs.

Question: Size of test cylinder

Question: Estimating in-place concrete strength

Question: Low-strength cylinder test results

Question: Resistance to cycles of freezing and thawing

Question: What is the intention of the ACI 318 Building Code?

Question: The effect of air content on concrete strength

Question: The effect of changes in proportions of the fine and coarse aggregate or the quantity of cementi...

Question: Mixture design and strength submittals

Question: Air tests for non-air-entrained concrete

Question: Using core strength to calculate compressive strength of an existing structure

Question: Using cube tests in lieu of cylinder tests

Question: Factors governing the strength of concrete

Question: How are the relatively small dosages of an admixture measured reliably and placed in the mixer?

Question: Is the cutting of cores or other shaped specimens directly from a completed structure ever used ...

Question: How can it be determined that an admixture will serve its intended purpose?

Question: Who selects the requirements for concrete for a project?

Question: Standards for 7-day and 28-day strength test results

Question: Requirements for a successful concrete structure

Question: The most important single factor affecting compressive strength

Question: If time is not available for preliminary tests, how can the desired strengths be ensured?

Question: Can tests be conducted by anyone?

Question: How do the code requirements get to the contractor?