CCIL EXAM WITH COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS WITH RATIONALES (VERIFIED ANSWERS) |ALREADY GRADED A

A sample contains aggregate larger than that appropriate for the size of the moulds or equipment. - ANSWERSIt must be wet-sieved prior to testing Information required on reports - ANSWERSConc mix no, Sample source, Batch time/date, Sample time/date, Project site, Sample location if different, Location of conc in structure, Technician name, Lab name/address, Signature of test report reviewer, Any deviation from test procedures Air Content - ANSWERSThe volume of air voids of plastic concrete, exclusive of pore space in aggregate particles, determined through observations of the change of air volume in concrete with a change in pressure. Slump - ANSWERSA measure of consistency of freshly mixed hydraulic cement concrete, equal to the subsidence, measured to the next 5mm, of the moulded substance immediately after the removal of the slump cone Slump Flow - ANSWERSThe horizontal spread of concrete immediately upon removal of the slump cone as a measure of the unconfined fluidity of concrete giving a relative degree of indication of the degree to which concrete can travel How many water-to-cementing materials ratios are needed for concrete trial mixes? - ANSWERS3 What temperature is considered stable before mixing concrete? - ANSWERS23 C +/- 2 C Where should cementing materials be stored? - ANSWERSIn a dry place, in moisture-proof containers What sieve must cementing materials be passed through before use to reject lumps? - ANSWERS1.25mm or finer Surface moisture in fine and coarse aggregate should be obtained using samples of what size? - ANSWERS500g-1000g How much time is spent mixing concrete? - ANSWERSMix 3 minutes, rest 3 minutes, mix 2 minutes Which sample can be re-used for casting cylinders? - ANSWERSSlump or slump flow, NOT air. Must be remixed into batch first Cylinder moulds - ANSWERSMust have nonabsorbent surfaces and be sufficiently rigid- Must be coated with mineral oil Cardboard moulds cannot be used for what strength? - ANSWERSGreater than 35MPa Flexural moulds - ANSWERSMust be rectangular and 50mm longer than the prescribed span. Must be watertight and rigid, nonabsorbent. Variation from specified cross-section is not to exceed 3mm. Coat with mineral oil. Tamping Rod for 100mm x 200mm cylinders - ANSWERSDiameter 10mm +/- 1mm and a Length of 450mm to 600mm. One end must be hemispherical. Tamping Rod for cylinders 150mm or greater, and rectangular moulds - ANSWERSDiameter 16mm +/- 1mm and a Length 450mm to 600mm. One end must be hemispherical. Internal Vibrators - ANSWERSRigi, flexible shaft; powered by electric motor. Frequency 120Hz or greater. Outside diameter 20mm to 40mm. Minimum height 50mm less than specimen being consolidated. Ratio for vibrating cylinders - ANSWERS4.0 or higher Vibrating beams - ANSWERSThe diameter of the element or thickness of a square vibrating element shall not exceed 1/3 the width of the mould. External vibrators - ANSWERSTable/plank type. Minimum 60Hz. Clamp mould securely to apparatus. Head mallet weight - ANSWERS0.6 kg +/- 0.3 kg. Strike-off Bar - ANSWERSSteel. 6mm x 25mm x 450mm. Water Tank - ANSWERS23 +/- 2 degrees C. Temperatue readings must be taken twice daily and be within 0.5 degrees accuracy. Water Tank Cleaning - ANSWERSWhen water contains 3g/L Ca at intervals not to exceed 24 months. Water Tank Room - ANSWERS95% or greater humidity, 23 +/- 2 degrees C, temperature readings twice daily 5 days a week within 0.5 degrees C accuracy. Temperature measuring - ANSWERSDevices must be able to measure temperatures between 0 and 50 degrees C, accurate to 0.5 degrees C. Moisture Room - ANSWERSTemperature must be read every 15 mins by a recorder- Must be accurate to 1 degree C. Verify temperature recorders - ANSWERSEvery 6 months or whenever there is a questi