Frequently Asked Questions

Technical Questions

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




Question: Curling, shrinkage, and w/cm

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

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

Question: How is the shrinkage of concrete determined?

Question: What is autogenous shrinkage?

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

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

Question: The effect of pozzolans on shrinkage

Question: Maximum temperature limits for hot-weather concreting

Question: Other important properties of concrete

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

Question: Do some water-reducing admixtures induce bleeding?

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

Question: Curing and curling of concrete slabs over vapor retarders

Question: Slabs-on-ground

Question: Evaluating the properties of hardened concrete

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

Question: The purpose of calcium sulfate (gypsum)

Question: Characteristics of aggregate affecting concrete strength

Question: Specialty admixtures

Question: What fibers are used in concrete?

Question: What nominal maximum sizes of aggregate are recommended?

Question: The effect of changes in proportions of the fine and coarse aggregate or the quantity of cementitious material on the strength

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

Question: How can the effectiveness of curing be measured?

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

Question: What is calcium-aluminate cement?

Question: Acceptable concrete cracking


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