ACI Concrete Strength Technician Exam Questions And Answers (Verified And Updated)

ACI Concrete Strength Technician Exam Questions And Answers (Verified And Updated) What is ASTM C1231? - answerStandard Practice for use of Unbonded Caps in determination of compressive strength of hardened cylindrical concrete specimens (C1231) The height (cavity) of the metal retaining ring must be - answer(25 +/- 3mm) (C1231) If the retaining ring is greater than 4in (100mm) it must be at least __ thick. If it is less than 4in, it must be at least __ thick. - answer.47 in (12mm) and .35in (9mm) (C1231) Bearing surfaces of the retaining ring must not have gauges greater than - answer.01 inches (.25mm) deep or .05in (32mm) surface area (C1231) For specimen ends, depressions under a straightedge must not exceed - answer.2 inches (5mm) measured across any diameter using a round wire edge (C1231) Depressions on ends of specimens that exceed ___ must be corrected by sawing or grinding - answer.2in (5mm) Procedures for capping enable concrete cylinders and cores to meet C617's practice requirements for___ and___. - answerperpendicularity and planeness Capping plates can be made of what material? (C617) - answerglass, machined metal, polished granite, or diabase (c1231) The inside diameter of the retaining rings shall not be less than _____% or greater than _____% of the diameter of the cylinder. - answer102% and 107% (c1231) Pad thickness must be - answer(13 +/- 2mm) (C1231) The diameter of the pad shall not be more than __ smaller than the inside diameter of the retaining ring - answer1/16 in (2mm) (C1231) Neither end of the cylinder shall depart from perpendicularity by more than __ degrees - answer.5 (C1231) Depressions on ends of specimens that exceed .2in (5mm) must be corrected by ___ or ___ - answersawing or grinding (C1231) Tolerance on Shore A durometer hardness is +/- __ - answer+/- 5 (C1231) The surface of the base plate that contacts the bearing block must be plane to within ___ in. - answer.002 in (.05mm) Unbonded caps can be used for ASTM C__, C___, and C___ - answerC31, C192, and C42 After application of the load, but before reaching 10% of the anticipated specimen strength, check to see that the axis of the cylinder does not depart from vertical by more than _____ degrees. - answer.5 degrees Qualification tests on an unbonded capping system must be repeated when ever there are changes in _____ (3) - answer-The design or dimensions of the retaining rings -Pad composition or thickness -The Shore A hardness by more than 5 units After application of the load, but before reaching _____ of the anticipated specimen strength, check to see that the axis of the cylinder does not depart from vertical by more than .5 degrees - answer10% What is ASTM C617 - answerStandard Practice for Capping Cylindrical Concrete Specimens What is ASTM C78 - answerStandard test method for Flexural strength of concrete (C78) When measuring the width and depth of the fractured face, take measurements to the nearest ___ - answer.05in (1mm) (C78) Can this test be conducted with a non motorized machine? - answerYes, so long as it applies force at a constant rate (C78) It is acceptable to use ___ ___ only when the gap between the specimen surface in contact with the blocks is not more than .015in or .40 mm - answerleather shims (C78) Gaps in excess of .015in or .4mm shall be eliminated only by - answercapping or grinding, not leather shims (C78) if the fracture occurs in the middle third of the span length, what formula is used to calculate modulus of rupture? - answerR= PL /bd^2 (C78) If the fracture occurs outside of the middle third but not by more than 5% of the span length, what formula is used to calculate modulus of rupture? - answer3Pa /bd^2 (C78) What formula is used to calculate the limits of the loading rate? - answerr=Sbd^2 /L