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 36 FAQs.

Question: Curing and curling of concrete slabs over vapor retarders

Question: What are shrinkage-compensating expansive cement and concrete?

Question: Curling, shrinkage, and w/cm

Question: What is the difference between synthetic microfibers and macrofibers?

Question: What nominal maximum sizes of aggregate are recommended?

Question: The effect of joints on the durability of concrete structures

Question: Would adding more cement serve the purpose of admixtures?

Question: Maximum temperature limits for hot-weather concreting

Question: The effect of aggregate characteristics on concrete shrinkage and permeability

Question: How is the shrinkage of concrete determined?

Question: Increasing the load capacity of a slab-on-ground using an overlay

Question: What fibers are used in concrete?

Question: Acceptable concrete cracking

Question: The effect of water-reducing admixtures on drying shrinkage

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

Question: How can the effectiveness of curing be measured?

Question: The effect of pozzolans on shrinkage

Question: Other important properties of concrete

Question: The effect of water-cementitious ratio on permeability and shrinkage

Question: When should saw cuts be made on a concrete slab?

Question: What are the primary benefits of using fiber-reinforced concrete compared to traditionally reinf...

Question: Characteristics of aggregate affecting concrete strength

Question: What is autogenous shrinkage?

Question: How should the appropriate fiber be selected for a specific application, and how is fiber dosage...

Question: Evaluating the properties of hardened concrete

Question: Slabs-on-ground

Question: The purpose of calcium sulfate (gypsum)

Question: Is there any measure of the completeness or adequacy of curing?

Question: Why are fibers used in concrete?

Question: Why use fiber-reinforced concrete?

Question: Specialty admixtures

Question: Do some water-reducing admixtures induce bleeding?

Question: Can the strength gain of concrete that has ceased due to drying out at early ages be restored by...

Question: What is the minimum fiber dosage? Is it possible to use less than the minimum dosage?

Question: What is minimum reinforcement for crack-width control and how is design accomplished using fiber?

Question: What is calcium-aluminate cement?