ACI - Concrete Strength Technician Training Exam Questions with 100% Correct Verified Answers .

ACI - Concrete Strength Technician Training Exam Questions with 100% Correct Verified Answers . Materials that can be used to cap hardened cement concrete cylinders. - ANSWER -Neat Portland Cement, Gypsum Cement, Sulfur T/F Plaster of paris is an example of a high-strength plaster - ANSWER -False Sulfur and gypsum cubes much show this compressive strength or the cylinder strength, whichever is greater. - ANSWER -5000 psi Strength of the paste depends on___, ___, and___. - ANSWER -Water cement ratio, time, type of cement These are avoided when a slight twisting motion is applied while capping. - ANSWER -Air voids and excess paste Sulfur material should not be used more than ___ times. - ANSWER -5 T/F When capping concrete cylinders with a compressive strength of 5000 psi or greater, it is permitted to reuse compound recovered from the capping operation of old caps. - ANSWER -False Sulfur mortar should be kept away from this while heating. - ANSWER -Water Sulfur mortar should be kept under a ___ with an___ for venting. - ANSWER Hood, exhaust Standard Practice for use of unbonded caps in determination of compressive strength of hardened concrete cylinders. - ANSWER -ASTM C1231 Thickness of pads (C1231) in Inches - ANSWER -1/2 Durometer used in C1231 with a tolerance of +/-5. - ANSWER -Shore A Type of pad with classifications in C1231. - ANSWER -Neoprene Height of the retaining ring used in unbonded capping. in inches - ANSWER -1 The inside diameter of the retaining ring shall be within ___ of the diameter of the cylinder. - ANSWER -102-107% Thickness of the retaining ring for 6 in and 4 in specimens respectively. - ANSWER -12 mm, 9 mm The bearing surfaces shall not have gouges or grooves greater than this depth. (mm) - ANSWER -0.25 Cylinders should be made in accordance with one of these procedures. - ANSWER -C31 or C192 Depressions in the concrete cylinder shall not exceed___in., with grinding, sawing or capping being the correction. - ANSWER -0.20 When tests are made to establish a permissible number of reuses, the tests within ___ of the highest strength level will be included in the reuse count. - ANSWER 2000 psi Qualification tests of unbonded caps are to be performed by___. - ANSWER Supplier/tester T/F C1231 establishes a maximum number of pad reuses that may not be exceeded under any circumstances. - ANSWER -False Psi range in which unbonded caps can be used. - ANSWER -1500-12,000 T/F Polyurthane or butyl pads with a hardness of 50 that will be used on concrete with a compressive strength of psi need not be qualified prior to use. - ANSWER -False T/F If a new neoprene pad this a Shore A durometer hardness of 50 is intended to test concrete cylinders with anticipated compressive strengths between psi, it may be used "as is" from the manufacturer without further qualification testing. - ANSWER -True The combination of a metal retainer and an elastomeric pad - ANSWER Unbonded cap