ACI Strength Exam Study Guide: Comprehensive Questions and Answers for 2024/2025, Exams of Construction

Download ACI Strength Exam Study Guide: Comprehensive Questions and Answers for 2024/2025 and more Exams Construction in PDF only on Docsity! ACI Strength Exam Study Guide | Comprehensive Questions and Answers Latest Updated 2024/2025 With 100% Verified Solutions Name the two allowable materials with with concrete cylinders may be capped with. - ✔✔I. High- strength gypsum II. Sulfur mortar III. Neat cement paste Name the three materials with with cylinders may be capped against. - ✔✔I. Glass II. Metal III. Granite Prior to beginning the capping procedure, what must the metal plate be inspected for? - ✔✔I. Grooves II. Gouches III. Indentations What is the maximum allowable size of any indentation on the base plate? - ✔✔0.010 in [0.25 mm] Upon receipt of the caping material, for how long can it be kept in intervals? - ✔✔3 months When must the neat cement paste be applied it to the cylinder? - ✔✔Immediately For how long must the concrete settle in the mold prior to applying the neat cement paste? - ✔✔2 to 4 hours Prior to capping, name the three tasks that must be performed on the cylinder. - ✔✔I. Inspect for any bumps greater than 1/8" II. Remove foreign debris. III. Remove any excess water or laitence. What is the required position of the concrete cylinder? - ✔✔90° ± 0.5° Name the required temperature range of the heated sulfar mortar mixture. - ✔✔265°F to 290 °F [130 °C to 145 °C] What is the maximum number of times that the heated sulfur may be used per cylinder capping procedure? - ✔✔5 times These procedures for capping enable concrete cylinders and cores to meet the standard practice's requirements for _____ and _____. - ✔✔perpendicularity ... planeness ... perpendicularity Equipment needed for the capping process includes capping ____ ____ devices and _____ pots. - ✔✔plates ... alignment ... melting Plates for neat cement and high-strength gypsum plaster caps should be made of ____, _____, or _____. - ✔✔metal ... glass .... granite Sulfar mortar cap plates should be formed against _____ or _____ plates. - ✔✔marble ... stone True or false? The purpose of the guide bar or bull's eye level is to ensure that caps remain perpendicular to the axi of the cylinder within 0.5 degrees. - ✔✔True To avoid accidents during reheating of cooled sulfur, use melting pots that have _____. - ✔✔Metal covers The technician should use a stiff layer of _____ to cap fresh concrete cylinders. - ✔✔Burlap Hardened concrete cylinders should be capped with ________, ______, or _______. - ✔✔cement paste ... gypsum .... mortar sulfur True or false? Laboratories must maintain records of the number of times that the pads are reused. - ✔✔True True or false? The unbonded end cap may be used greater than 50 times. - ✔✔True, if the compresive strength is less than 7000 psi [50 MPA] After 50 uses, test results may be used for greater than 50 times at... A. ±5000 psi of average strength B. ±5000 psi of highest strength C. ±2000 psi of average strength D. ±2000 psi of highest strength - ✔✔D. ±2000 psi of highest strength When qualification tests of unbonded pads are required, they are performed b the _____ or _____. - ✔✔d True or False? This standard practice establishes a maximum number of pad reuses that may not be exceeded under any circumstances. - ✔✔True True or false? Polyurethane or butyl pads with a Shore A durometer hardness of 50 that will be used on concrete with a compressive strength of 10 to 40 MPa [1500 to 6000 psi]. It may be used "as is" from the manufacturer without further qualification testing. - ✔✔False To keep track of pad usage, the user is required to maintain records that will include _____, _____, and _____. - ✔✔date placed in service ... pad durometer ... number of uses True or false? The term "unbonded cap" refers to the combination of a metal retainer and elasomeric pad. - ✔✔True True or false? Practice C1231/C1231M may be used instead of the capping requirements of Practice C617/C617M. - ✔✔True True or false? The pads provide a uniform distribution of load from the bearing blocks of the testing machine by deforming in initial loading to conform to the contour of the ends of the cylinder. - ✔✔True When qualifying unbonded caps, strengths below _____ of the average obtained from the bonded caps is considered unacceptable. - ✔✔2% True or false? Practice C1231/C1231M contains step-by-step procedures for aligning the specimens in the testing machine through complete failure of the cylinder. - ✔✔True The pads used in this practice must be _____ thick, and the diameter shall not be more than ____ smaller than the inside diameter of the retaining ring. - ✔✔1/16 inch ... 2 mm The height of the metal retaining ring must be _____. - ✔✔in The inside diameter of the retaining rings shall not be less than _____ or greater than _____ of the diameter of the cylinder. - ✔✔2 mm ... Depressions in the ends of cylinders that exceed _____ must be corrected by sawing or grinding prior to testing. - ✔✔1/8 inch Qualification tests on an unbonded capping system must be repeated whenever there are changes in _____, _____, or _____. - ✔✔d Name the maximum density required for concrete cylinder specimens to undergo the Compressive Strength Test. - ✔✔50 pcf Within what time period must callibration be performed on the compressive strength testing machine? A. 11 months B. 12 months C. 13 months D. 24 months - ✔✔C. 13 months Within what percent of the maximum load should the dial be readable within? A. 1% B. 2% C. 5% D. 10% - ✔✔A. 1% Specimens shall NOT be tested if any individual diameter of a cylider differes from the other diameter of the same cylinder by more than: A. 1% B. 2% C. 3% D. 4% - ✔✔B. 2% The number of individual concrete cylinders measured to determine the average diameter may be reduced to: A. 1 in 3 specimens B. 1 in 10 specimens C. 2 specimens D. 3 specimens E. A and C F. B and D - ✔✔F. B and D The diameter of the concrete cylinder is measured along the: A. Top B. Middle C. Bottom D. Top and Bottom - ✔✔B. Middle True or false? When conducting compression tests of moist-cured specimens, wait at least three days after their removal from moist storage before testing. - ✔✔True Test specimens should be ____ during the period between storage and testing. - ✔✔cured When placing the lower bearing block on the table or plate, place the _____ up. - ✔✔block Align the _____ of the specimen with teh _____ of thrust of the spherically shaped block. - ✔✔d Prior to testing the specimen, verify that the load indicator is _____. - ✔✔calibrated Apply the load _____ and without _____. - ✔✔continuously ... shock True or false? A higher rate of loading shall be permitted during the application of the first half of the anticipated loading phase. - ✔✔False When the specimen fails, record the _____ carried by the specimen during the test, and note the _____. - ✔✔load ... pattern Calculate the compressive strength by dividing the _____ by the average _____ area determined. - ✔✔load ... cross-sectional Which of the follwoing should the test report include: A. The ID number B. The maximum load C. The age of the specimen D. The cross-sectional area E. Any defects in the specimen or caps F. All of these G. All of these plus more - ✔✔G. All of these plus more The resutls of this test method may be used to determine quality control of concrete proportioning mixing, and _____ operations, compliance with _____, or for evaluating effectiveness of _____. - ✔✔strength ... regulations ... concrete The load of a compression machine can be registered on a _____ or in _____. - ✔✔d The load readings of the load-applying blocks should be between _____ and _____ of the estimated load. - ✔✔3% ... 6% Name the thickness, width, and length of the leather shims. - ✔✔0.25 in [6 mm] thick 1.0 to 2.0 in [25 to 50 mm] wide As long as the full span of the specimen The load shall be applied at a constant rate between ... and ... . - ✔✔125 psi/min [0.9 MPa/min] to 175 psi/min [1.2 MPa/min] What is the formula to calculate loading rate, r? - ✔✔r = [Sbd^2]/L r = loading rate [lb/min] S = rate of increase of maximum stress [125 psi/min - 175 psi/min] b = average width of the specimen as oriented for testing [in] d = average depth of specimen as oriented for testing [in] L = span length [in] Name the formula to calculate R, modulus of rupture, for when the specimen breaks within the middle third. - ✔✔R = [PL] / bd^2 R = modulus of rupture [psi] P = maximum load applied incited by the testing machine [lb] L = span length [in] b = average width of specimen at fracture [in] d = average depth of specimen [in] at fracture Name the formula to calculate R, modulus of rupture, for when the specimen breaks outside of the middle third. - ✔✔R = [3Pa] / bd^2 R = modulus of rupture [psi] P = maximum load applied incited by the testing machine [lb] a = average distance between line of fracture and the nearest support measured on teh tension surface of the beam [in] b = average width of specimen at fracture [in] d = average depth of specimen [in] at fracture True or false? Hand operated machines having pumps that do not provide a continuous loading in one stroke are NOT permitted. - ✔✔True Bearing blocks used in the _____ method must ensure that forces applied to the beam will be perpendicular to the face of the specimen and applied without eccentricity. - ✔✔d The testing equipment must be capable of maintaining distances between load-applying and support blocks constant within _____. - ✔✔50 psi/min Which of the following are requirements for load-bearing and support blocks: A. They should be 2.50 in [65 mm] high or less. B. They should be half as wide as the specimen. C. THey should be in contact with the rod or ball. - ✔✔C. They should be in contact with the rod or ball. Test specimen surfaces should be smooth and free of _____, _____, _____, or _____. - ✔✔debris ... laitence ... gouges ... True or false? In relation to the applied force the loading system should be centered during the procedure. - ✔✔True C. ± 0.5% D. ± 1.5%' E. ± 2.0% - ✔✔E. ± 2.0% To determine the average width, depth, and line of fracture location of the specimen, you should take _____ measurements of each dimension. A. 2 B. 3 C. 4 D. 5 - ✔✔B. 3 The final report shoudl include both the average width and depth to the nearest: A. 0.05 in [1 mm] B. 0.25 in [6.4 mm] C. 0.5 in [12.7 mm] D. 1 in [25.4 mm] - ✔✔C. 0.5 in [12.7 mm] True or false? Specimens should be completedly dry when performing the Compressive Strength Test. - ✔✔False If the 0.004 inch feeler gauges slides, it is still acceptable as long as it does not move by: A. 0.5 inches B. 1 inch C. 2 inches D. 3 inches E. None of the above - ✔✔B. 1 inch After curing, name the 3 checks to perform on the concrete cylinder. - ✔✔I. Perpendicularity II. Planeness III. Diameter Name three methods to crrect for insufficient perpendicularity or bumps on the clinder. - ✔✔I. Bonded cap II. Grind III. Unbonded cap Briefly describe how to check for the perpendicular of a concrete cylinder. - ✔✔Run a 1/16th inch feeler gauge along the side of the cylinder in 2-3 locations. Bumps on caps should not exceed: A. 0.05 inches B. 0.1 inches C. 0.2 inches D. 0.5 inches E. None of the above - ✔✔C. 0.2 inches Round the nearest cylinder midpoint diameters to the nearest: A. 0.01 inches B. 0.05 inches C. 0.1 inches D. 0.5 inches E. None of the above - ✔✔A. 0.01 inches The tensile strength of concrte is approximately _____ of the compressive strength of the same concrete. - ✔✔1/10th Cement paste may only be used on: A. Hardened molded cylinders B. Freshly molded cylinders C. Both A and B - ✔✔B. Freshly molded cylinders Gypsum and sulfure should be inspected every: A. 1 month B. 3 months C. 6 months D. 12 months - ✔✔B. 3 months Unbonded caps are NOT to be used for acceptance testing of concrete with compressive strength below _____ or above _____. - ✔✔1500 psi [10 MPa] ... 12000 psi [80 MPa]