Technical Questions

Question: Estimating in-place concrete strength

Question: How can durable aggregates be ensured?

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

Question: Curing Cylinders for Acceptance Testing

Question: What test conditions affect the results of compressive strength tests of concrete?

Question: Size of test cylinder

Question: Measurement of setting time

Question: False and flash set

Question: Strength of concrete

Question: Standard specifications for cements

Question: Unsoundness in portland cement

Question: The cause of false set

Question: Using and handling pozzolans

Question: Improving the abrasion resistance of concrete

Question: What methods of capping are recommended for compression specimens?

Question: Why are many non-destructive tests used as “estimators” of concrete strength?

Question: How is the resistance to freezing and thawing determined?

Question: How is the abrasion resistance of concrete determined?

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

Question: The purpose of calcium sulfate (gypsum)

Question: Factors affecting cement properties

Question: Effects of cement fineness on cement properties

Question: What is an admixture?

Question: Do different admixtures of a given type always perform the same?

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

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

Question: How is the air content of freshly mixed concrete determined?

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

Question: Tolerances for concrete slabs supporting steel tanks

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

Question: Definition of setting time

Question: The difference between setting and hardening

Question: Characteristics of cement that affect compressive strength

Question: What is a pozzolan?

Question: What does a pozzolan do in the concrete?

Question: Importance of using pozzolans in hydraulic and environmental structures

Question: Are pozzolans all alike?

Question: The effect of pozzolans on water demand

Question: The effect of pozzolans on shrinkage

Question: What are blended cements?

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

Question: What is an air-entraining admixture?

Question: What are water-reducing admixtures?

Question: Do some water-reducing admixtures induce bleeding?

Question: How is the required strength selected, measured, and obtained?

Question: The most important single factor affecting compressive strength

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

Question: Does the method of molding test specimens affect the test results?

Question: What procedure should be followed for standard curing of specimens for strength tests?

Question: What are the ultrasonic pulse velocity and the pulse echo tests?

Question: Is pulse velocity related to strength?

Question: What other uses are there for the pulse velocity?

Question: How is the permeability of concrete determined?

Question: How is the resistance to sulfate determined?

Question: How is the shrinkage of concrete determined?

Question: Tolerances for floors supporting operable partitions

Question: Rebound hammer and in-place strength testing

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

Question: Air tests for non-air-entrained concrete

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

Question: Low-strength cylinder test results

Question: Air content common limits

Question: Factors affecting permeability

Question: The relationship between porosity and permeability of concrete

Question: Why is Type IV cement rarely produced and Type V cement rarely used?

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

Question: Benefits of using slag cement

Question: What is fly ash?

Question: Do all fly ashes behave in a similar way?

Question: What is silica fume?

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

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

Question: What is aggregate?

Question: Requirements for storing and handling aggregate

Question: Why is combined aggregate grading used?

Question: Aggregate classification by density

Question: What are high-density aggregates?

Question: Important requirements of a concrete aggregate

Question: The effect of aggregate on concrete durability

Question: Characteristics of aggregate affecting concrete strength

Question: The effect of surface texture and cleanness on concrete strength

Question: The effect of aggregate shape on concrete strength

Question: The effect of aggregate grading on concrete strength

Question: The effect of maximum size of aggregate on concrete strength

Question: The effect of aggregate strength on concrete strength

Question: What are set-controlling admixtures?

Question: Are retarding admixtures reliable as to the time of setting?

Question: What fibers are used in concrete?

Question: Why is the workability of concrete important?

Question: How is workability measured and specified?

Question: How can the adequacy of mixing be determined?

Question: Are there any tests that may be made directly on the structure to determine if the concrete has ...

Question: How should samples of freshly mixed concrete be taken in the field to provide information on con...

Question: How is the slump test made?

Question: Why is the slump test not an absolute measure of consistency or workability?

Question: When is the slump test useful in detecting changes in the concrete?

Question: When does the slump test provide a useful indication of workability?

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

Question: Is density a good indicator of air content?

Question: How is the temperature of concrete measured?

Question: What irregularities are to be avoided in the test specimen?

Question: How is strength estimated by the maturity method?

Question: How is the air content of hardened concrete determined?

Question: Curing and curling of concrete slabs over vapor retarders

Question: Addition of lime in curing tanks