ACI CONCRETE STRENGTH TESTING

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ACI CONCRETE STRENGTH TESTING

TECHNICIAN EXAM NEWEST ACTUAL

EXAM 200 QUESTIONS AND CORRECT

DETAILED ANSWERS (VERIFIED ANSWERS) |A+

GRADED

(C78) How should force on the specimen be loaded? - ANSWER-continuously and without shock

(C78) Apply the load at a rate that constantly increases the maximum stress on the tension face between __psi/min and __psi/min - ANSWER-between 125psi/min and 175 psi/min (.9MPa/min and 1.2MPa/min

(C78) The span length of a test specimen should be within what percent of three times the depth of the specimen as tested? - ANSWER-within 2% of three times the depth

(C617) Sulfur should be heated to what temperature range? - ANSWER-265 and 290 degrees F 1 / 4

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(c617) Measure and record thickness of the cap to the nearest ___in - ANSWER-.01inch

(C617) When capping cylinders it is acceptable to ___ but not rock the capping plate in an effort to extrude excess material and air voids - ANSWER-twist

(C617) What type of gas can be produced when sulfur mortar is contaminated with organic material? - ANSWER-Hydrogen sulfide gas

(C617) When capping cylinders it is acceptable to twist but not rock the capping plate in an effort to extrude___ ___ and ___ ___ - ANSWER-excess material and air voids

(C617) Neat cement paste caps can ___ and ___ if allowed to dry - ANSWER-shrink and crack

(C617) The end of a capped cylinder must be plane to within ___in - ANSWER-.002in (.05mm)

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(C617) Empty the pot and recharge with fresh material to ensure the oldest material is not reheated more than how many times? - ANSWER-5 times

(C617) Cement paste should be applied to freshly molded cylinder within how many hours after molding to allow for settling of the concrete specimen - ANSWER-within 2 to 4 hours

(C617) The vertical distance between the highest and lowest points on the end of an uncapped cylinder shall not exceed ___ - ANSWER-1/8 inch (3mm)

(C617) The guide bar/bullseye level ensures caps are perpendicular to the axis within __ degrees - ANSWER-.5 degrees

(C617) Remove and replace any caps having voids or steam pockets greater than __in - ANSWER-1/4 inch (6mm)

(C617) Metal capping plates should be free of gouges greater than ___in - ANSWER-.01 inch (25mm)

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(C617) In general with high strength gypsum paste, a capping plate may be removed within how many minutes without visibly damaging the cap? - ANSWER-45 mins

What is ASTM C39? - ANSWER-Standard Test Method for Compressive strength of cylindrical concrete specimens

(C39) Compressive strength should be expressed to the nearest ___psi - ANSWER-10 psi (.1 mPA)

(C39) A correction factor is needed if the length to diameter ratio is ___ or less - ANSWER-1.75 or less

(C39) A 28 day old specimen must be tested within how many hours of this age? - ANSWER-20 hours

(C39) The percent of error for loads should not exceed what percent? - ANSWER-+/- 1%

What ASTM standard describes the apparatus, materials, and procedures for capping freshly molded concrete cylinders with neat cement? - ANSWER-ASTM C617

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