ACI Concrete Field Testing Technician - Grade I Questions and Answers

The end of the temperature sensing portion of the temperature measuring device is submerged a minimum of __mm [__in.] into the freshly mixed concrete. - Answer-77mm /3in. The temperature measuring device shall be capable of accurately measuring the temperature of freshly mixed concrete to +- __C [+__F] throught a range of __. - Answer-0.5 C / +-1F / 0-50 Decrees C The temp. measuring device shall be verified __, or whenever there is a question of __. - AnswerAnnually / accuracy The temp of concrete may be measured in a wheelbarrow? T/F - Answer-True The temp. of concrete may be measured in a wall form. T/F - Answer-True A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temp. T/F - Answer-False What must be done to the sample container prior to sampling the concrete - Answer-It must be dampened with water What must be done to the concrete surrounding the temp measuring device after the device is submerged in the fresh concrete? - Answer-Gently press the concrete at the surface around the measuring device. How long must the temperature measuring device remain in the freshly mixed concrete? - Answer-At least 2 min., no longer than 5 min. After the temperature of the concrete is read, what is then required? - Answer-Reporting of temp. The temp. of concrete is reported to the nearest __. - Answer-1 degree FAccording to ASTM C1064, what is one reason to take the temperature of concrete? - Answer-to verify conformance to a specific requirement. A max. temp. of freshly mixed concrete is specified in ASTM C1064. T/F - Answer-False The sample of concrete used for temperature determination must be rodded 25 times. - AnswerFalse Sampling by this method covers procedures or obtaining representative samples, on which test are to be performed to determined __ with quality requirements of the specifications under which the concrete is furnished. - Answer-Compliance This method covers sampling from four types of mixers, which are __, __, __, and __. - AnswerStationary mixers / Paving mixers / revolving drum mixers / open top mixers The elapsed time between obtaining the first and final portions of a composite sample shall not exceed __ min. - Answer-15 min. Portions of a composite sample shall be thoroughly mixed before beginning test on the sample. T/F - Answer-True Start tests for slump, temp, and air content within __ min. after obtaining the final portion of the composite sample. - Answer-5 min. start molding specimens fr strength tests within __ after fabrication the composite sample. - Answer- 15 min. The concrete sample must be protected from contamination and __. - Answer-Rapid evaporation The maximum size sample for making strength test specimens is __ ft cubed - Answer-1 foot cubed. When sampling from a STATIONARY mixer, the batch must be sampled at __ or more regularly spaced intervals during discharge of the middle portion of the batch. - Answer-2When sampling from a PAVING mixer, obtain samples from at least __ different portions of the pile and combine them into one composite sample for test purposes - Answer-5 When sampling from a REVOLVING DRUM TRUCK mixer, sample the concrete by collecting __ or more portions taken at regularly spaced intervals during discharge of the middle portion of the batch. - Answer-2 Concrete samples from a truck mixer will be obtained before any water or admixtures are added to the mixer at the job site. T/F - Answer-False The composite sample from a truck mixer must be obtained from the __ portion of the batch. - Answer-Middle. When the concrete contains aggregate larger than that permitted for a particular test method, the sample of concrete must be __ __ before making the test. - Answer-Wet-seived