Technical Questions

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

Question: What is mass concrete?

Question: Consolidation of concrete—required or not?

Question: Heat of hydration and the importance of controlling it

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

Question: Requirements for durable concrete

Question: Popouts or popoffs?

Question: Improving the abrasion resistance of concrete

Question: Maximum temperature limits for hot-weather concreting

Question: What steps are taken in the repair of concrete structures?

Question: Resistance to cycles of freezing and thawing

Question: The effect of aggregate on concrete durability

Question: Benefits of using slag cement

Question: Could a sulfate-resisting cement and slag cement be combined and used for concrete exposed to sulfates attack?

Question: Air tests for non-air-entrained concrete

Question: The relationship between porosity and permeability of concrete

Question: Protecting concrete from cycles of freezing and thawing

Question: Do we always need to repair cracked concrete?

Question: How is the shrinkage of concrete determined?

Question: Other important properties of concrete

Question: Knowledge of concrete properties

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

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

Question: Epoxy-coated reinforcement and cover depth against ground

Question: Evaluating the properties of hardened concrete

Question: How can durable aggregates be ensured?

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

Question: How is the selection of mixture proportions affected by the materials to be used and the placing requirements?

Question: Joint deterioration mechanism and prevention

Question: Acceptable concrete cracking

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

Question: How is the abrasion resistance of concrete determined?

Question: Specialty admixtures

Question: Commonly used accelerating admixture

Question: Why is combined aggregate grading used?

Question: What is D-cracking?

Question: The importance of proper drainage

Question: Precautions against sulfate attack

Question: Can you use any source of water as mixing water?

Question: Precautions to resist acid attack

Question: Protecting against excessive expansion due to alkali-aggregate reaction (AAR)

Question: How is the resistance to alkali-aggregate reaction (AAR) determined?

Question: Chloride concentration in soil and exposure classes

Question: Factors affecting permeability

Question: How is the resistance to sulfate determined?

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