Frequently Asked Questions

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Technical Questions

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





Question: What is mass concrete?

Question: Pozzolans in mass concrete

Question: Heat of hydration and the importance of controlling it

Question: Maximum temperature limits for hot-weather concreting

Question: Requirements for durable concrete

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

Question: Temperature limits for mass concrete

Question: Water Curing Mass Concrete Structures

Question: Definition of concrete, hydraulic cement, mortar, and grout

Question: Benefits of using slag cement

Question: What does a pozzolan do in the concrete?

Question: What is the effect of freezing on concrete?

Question: How to Control Mass Concrete Temperature during Construction

Question: Using and handling pozzolans

Question: Why is consolidation needed?

Question: How is the temperature of concrete measured?

Question: The effect of pozzolans on water demand

Question: What methods are commonly used to ensure sufficient moisture for curing concrete?

Question: Material Requirements for Mass Concrete

Question: Commonly used accelerating admixture

Question: What consideration should be given to water that may be lost from concrete between the time it l...

Question: Could a sulfate-resisting cement and slag cement be combined and used for concrete exposed to su...

Question: Mixture design and strength submittals

Question: What test is available to evaluate the behavior of no-slump concrete as it is vibrated?

Question: Temperature Control Time

Question: What is slag cement or ground granulated blast-furnace slag (GGBFS)

Question: Minimum Dimension of a Structure

Question: How should the aggregates and other ingredients be measured to obtain uniformity in proportions?

Question: What are rebound, penetration resistance, and pullout tests?

Question: Definition of setting time

Question: Can the heat liberated by the hydrating cement be relied on to give protection during cold weather?

Question: What does ACI recommend regarding water-cement (w/c) ratios or admixtures to improve workability...

Question: How can the surface or free water carried by the aggregates be determined?

Question: Predicating Temperature for Mass Concrete

Question: What correction should be made for absorbed water and surface water carried by the aggregates?

Question: How much water goes into combination with the cement during the hardening of concrete?

Question: Is storing the specimens on the structure always a satisfactory procedure for estimating in-plac...

Question: How is the water-cementitious material ratio (w/cm) expressed?

Question: What are the essential requirements of consistency?

Question: How is the slump test made?

Question: The making of portland cement

Question: If the paste is ample in amount, but is too thin and watery to float the aggregate particles, wh...

Question: What is yield?