ICRI Concrete Surface Repair Technician s Performance Examination Rubric

Transcription

1 ICRI Concrete Surface Repair Technician s Performance Examination Rubric This is the examination rubric used to review and qualify the performance components of the ICRI Concrete Surface Repair Technician Grade 1 Certification Program (Tier 2). This rubric can be used to assess either live or video recorded performance exams. Grading: Additional aspects of each of the Quality Controls (QCs) included here are assessed in the online ICRI Concrete Surface Repair Technician Educational Program (Tier 1) of this certification. Earning a Tier 2 full certification requires passing the online Tier 1 Educational Program, the online Tier 2 Knowledge Exam, and this Performance Examination. Passing the performance examination requires correctly following the Additional Instructions and demonstrating all of the Observable Criteria listed for each of the QCs in this Performance Examination Rubric. Judge s Instructions: Document each of the Observable Criteria as or by marking an X in the corresponding box. Marking an Observable Criteria as indicates that the Observable Criteria was demonstrated correctly. Examinee s Name (print): Judge s Name (print): Judge s Signature: Date Performance Examination Performed: Date Performance Examination Assessed: Performance Examination Results (circle one): ASTM C143/C143M Passed Failed ASTM C1611/C1611M Passed Failed ASTM C31/C31M Passed Failed ASTM C1583/C1583M Passed Failed (ICRI 210.3R) Judge s es:

2 Slump: Conventional Ready Mix Concrete ASTM C143/C143M Standard Test Method for Slump of Hydraulic-Cement Concrete Additional Instructions: For this exam, the specified slump is 4 (+ or- 1 ) [100 mm (+ or 25 mm)]. 1 The mold (cone), scoop, tamping rod, and measuring device meet the requirements of ASTM C The concrete s coarse aggregate size was verbally stated and was within applicability limits of the test method (up to in. [38 mm] in size). 3 The interior of the mold was dampened prior to filling. 4 The mold was placed on a rigid, flat, level, moist, non-absorbent surface, free of vibration, and large enough to contain all of the slumped concrete. 5 The mold was held firmly in place from the time of filling to the time of lifting. This can be achieved by either standing on both foot pieces, or by clamping to a base plate in accordance with ASTM C The mold was filled in 3 layers, each one-third the volume of the mold, using the scoop. 7 Each layer was rodded 25 times, uniformly over the cross section, using the rounded end of the tamping rod. 8 The bottom layer was rodded to its full depth. 9 The second and third layers were rodded to a depth extending approx.1 (25 mm) into the previous layer. 10 The third layer was overfilled so that the concrete remained at or above the top of the mold during rodding. If the level of concrete dropped below the top of the mold during rodding, rodding was stopped and more concrete was added to keep an excess of concrete above the top of the mold at all times during 11 After the third layer was rodded, the concrete at the top of the mold was struck off with the tamping rod using a screeding and rolling motion. 12 After striking off, the mold was immediately removed in a vertical direction. The mold was lifted straight up for 1 (30.5 cm) in the specified time with no lateral or torsional motion. 13 From the filling of the mold thru its lifting occurred within a 2.5 minute window. 14 The slump was immediately and correctly measured and verbally stated to the nearest 0.25 (6 mm). 15 The test was discarded and repeated if a decided falling away or shearing off of the concrete from one side or portion of the mass occurred. 16 The recorded slump was stated verbally correct as being within or out of the specified range.

3 Slump Flow: SCC ASTM C1611/C1611M Standard Test Method for Slump Flow of Self-Consolidating Concrete Additional Instructions: For this exam, the specified slump flow is (51 56 cm). 1 The concrete s coarse aggregate size was verbally stated and was within applicability limits of the test method (up to 1 in. [25 mm] in size). 2 The mold (cone), base plate (min diameter of 3 or 915 mm), strike-off bar, measuring device, sample receptacle, and pouring vessel meet the requirements of ASTM C The work surface and interior of the mold were dampened prior to filling. 4 The mold was placed on a flat, level, non-absorbent work surface, free of vibration, and large enough to contain all of the slumped concrete. This can be a base plate or an adequate concrete surface. 5 The mold was held firmly in place from the time of filling to the time of lifting. 6 The concrete sample was remixed just prior to being poured into mold. 7 The mold was slightly overfilled with concrete using the pouring vessel. 8 The concrete at the top of the mold was stuck off with the tamping rod using a 9 Excess concrete around the mold was removed prior to lifting the mold. 10 The mold was lifted vertically straight up for 9 +or- 3 (225 mm +or- 75 mm) in the specified time with no lateral or torsional motion. 11 From the filling of the mold thru its lifting occurred within a 2.5 minute window. 12 After the slumped concrete stopped flowing, two diameter measurements were correctly taken at ~90 degrees from each other. The measurements were recorded to the nearest 0.25 (6 mm). 13 The slump flow was correctly calculated by averaging the two diameters to the nearest 0.5 (13 mm). 14 The test was discarded and repeated if the two diameter measurements differed by more than 2 (50 mm). 15 The recorded slump flow was stated verbally correct as being within or out of the specified range. e: Filling the mold can be by Procedure A (Upright Mold) or Procedure B (Inverted Mold). Refer to specification/ldp requirements.

4 Strength: Making and Curing Cylindrical Specimens ASTM C31/C31M Standard Practice for Making and Curing Concrete Test Specimens in the Field Additional Instructions: For this exam, only one (1) test specimen is required to be cast. 1 The cylinder mold, tamping rod, mallet, and placement/finishing tools meet the requirements of ASTM C31. 2 The cylinder diameter is correct for the nominal maximum size of the coarse aggregate in the concrete. 3 Specimens were molded on a level, rigid surface, free of vibration and other disturbances. 4 The concrete was correctly consolidated in the mold by rodding in two equal layers for 4 (100 mm) diameter mold, or three equal layers for 6 (150 mm) diameter mold. 5 Each layer was rodded 25 times, uniformly over the cross section, using the rounded end of the rod. 6 The bottom layer was rodded throughout its depth. 7 The upper layer(s) were each rodded to a depth extending approx. 1 (25 mm) into the previous layer. 8 After each layer is rodded, the outsides of the mold were lightly tapped with a mallet 10 to 15 times. 9 Under-filled molds were adjusted with more concrete and overfilled molds had excess concrete removed and the surface leveled and finished by striking off with the tamping rod or trowel. 10 The molds (cylinders) were adequately marked to identify them, the date molded, and the concrete they represent. 11 For standard curing and acceptance testing: immediately after finishing, cylinders were correctly placed in a location for initial curing and protection from impact and the elements. 12 For field curing: cylinders were stored in or on the structure near the point of concrete deposit represented by the cylinders, protected from the elements, and exposed to the same temperature and moisture environment as the placed concrete. e: Use of a vibrator for consolidation of concrete within the mold, transportation of specimens to the testing laboratory, and compressive strength testing that meets the requirements of ASTM C39 are beyond the scope of this certification.

5 Bond: Pull-off Test ASTM C1583/C1583M Standard Test Method for Tensile Strength of Concrete Surfaces and the Bond Strength or Tensile Strength of Concrete Repair and Overlay Materials by Direct Tension (Pulloff Method) ICRI Technical Guideline No R 2013 Guide for Using In-Situ Tensile Pulloff Tests to Evaluate Bond of Concrete Surface Materials Additional Instructions: For this exam, ASTM sets the minimum standards that you are evaluated against. ICRI 210.3R gives additional guidance on performing the pulloff test in repair areas and if used, you will also be evaluated against. The key differences between the ASTM standard and ICRI guideline involves acceptable core diameter and rigid discs/testing device equipment, the depth that should be drilled into the existing concrete, and frequency of specimen tests. For this exam, one (1) pull-off test is to be performed on a concrete slab, block, or repair. When testing on a concrete slab or block (non-composite), it is acceptable to drill to a depth of only 1/2 (13 mm) below the surface. If testing on a repair, actual thickness of repair material should be verbally stated and used during performance of the test method. 1 The core drill and barrel meet the requirements of either ASTM C1583 (with diamond impregnated bits nominally 2.0 in. [50 mm] inside diameter) or ICRI 210.3R (with core bit up to 3 [75 mm] inside diameter). 2 The rigid disc and tensile loading device meet the requirements of either ASTM C1583 (steel discs 2.0 in. [50 mm] diameter and at least 1.0 in. [25 mm] thick) or ICRI 210.3R (steel discs 2-3 in. [50-75 mm] diameter with a minimum thickness of 1 in. [25 mm] for 2.0 in [50 mm] disc or 1.25 in. [32 mm] for 3.0 in [75 mm] disc) or aluminum discs of 2 in. (50 mm) diameter at a minimum thickness of 1.25 in. [32 mm]). 3 The coring location was free of reinforcing steel, PT tendons, and electrical conduits. 4 The core was drilled perpendicular to the surface and to a minimum depth of 0.5 (13 mm) below the composite interface. ICRI recommends a minimum depth of 1 (25mm) or one-half the core diameter, whichever is greater, into the existing concrete below the composite interface. When testing on a concrete slab or block (non-composite), core was drilled to a minimum depth of 1/2 (13 mm) below the surface. 5 The core was intact after drilling and still connected to the existing substrate after the core drill was removed. 6 The rigid disc was properly attached to the core surface at the test location. This includes surface preparation of the core surface and disc as required by the adhesive manufacturer, allowing any water on the surface to dry before placing adhesive, preventing any adhesive from running down the sides of the drilled core, and centering the disc on the core specimen. 7 The testing device was set-up so that the applied force was parallel and coincident with the axis of the core specimen.

6 8 Load was applied in a specified uniform and constant rate, and avoided abrupt starts and stops of loading. 9 The ultimate tensile load applied was accurately stated verbally from the testing device. 10 The bond or tensile strength (depending on location of failure) was accurately calculated and verbally stated to the nearest 1 psi (0.01 MPa).