Cast-in-Place Concrete Connections for Precast Deck Systems (2011)

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G-i Appendix G Large-Scale Laboratory Bridge and Subassemblage Core Analysis

G-1 G.1 Introduction to Coring Analysis Several core samples were removed from the large-scale bridge and subassemblage specimens to investigate the presence of internal reflective cracking. The cores were analyzed initially by the naked eye, and subsequently with the aid of a microscope. Prior to being examined, the cores were prepped, which included rinsing them lightly under water, wiping them gently to remove any remaining sludge from the coring process, and patting them dry with paper towels. The cores were reassembled if broken in multiple sections, and the general characteristics of the core were documented (e.g. core height, diameter, and number of sections). The cores were initially examined without the use of the stereomicroscope. Any readily visible cracks observed using only a magnifying glass and a bright light were marked, which will be described later in this section. When it became too difficult to observe the crack by this method, the cores were placed under the viewing objective of the stereomicroscope and examined further for cracks. The stereomicroscope employed to examine the cores was an Olympus Stereomicroscope SZX12, made available for use by the University of Minnesota’s Institute of Technology Characterization Facility. In addition, an Olympus DP10 digital camera was used to take photos of specimens under the viewing objective. The stereomicroscope level of magnification used to examine the cores ranged between 2.1X to 27X magnification. The cores were first typically examined using a magnifying glass before being placed under the stereomicroscope. When a crack was identified, the core was placed under the microscope and the entire visible length of the crack was located using a magnification anywhere from 10X to 27X. To assist in locating the cracks, telescoping lights were positioned such that the cracks were easier to locate. Figure G.1 shows the stereomicroscope and indicates where the digital camera and telescoping lights were mounted. Once a crack was identified under the microscope, it was marked using a dotted line of red ink along the visible length of the crack, as shown in Figure G.2. A crack gage was used to measure the crack widths along the length of the crack. The measured crack widths were indicated on the surface of the core with pencil, as shown in Figure G.3, along the length of the crack according to the crack width classification categories defined in Table G.1. The orientation, depth, and type of the crack were documented on a supplementary form. During examination of the cores, visible cracks were the only item of the core that was located and marked. In addition, the examination also included looking for indications of potential crack location. Most commonly, these notes referred to location and orientation of an inclined plane between two sections of a broken core because these planes may indicate that a crack was present prior to the sections breaking apart.

G-2 Figure G1: Photograph of Olympus Stereomicroscope SZX12 used for core analysis Figure G2: Identified crack marked on core specimen using red ink

G-3 Figure G3: Crack widths marked on core specimen in pencil Table G1: Crack width classification categories Crack Classification Crack Width (W) 0.0021 W < 0.002” A 0.002” ≤ W < 0.008” B 0.008” ≤ W < 0.023” C 0.023” ≤ W < 0.200” D W ≥ 0.200” 1Cracks classified as having width < 0.002” are shown simply with a “2” in Table G2. G2: Tabulation of Cracking in Cores Cracking was tabulated for each core specimen. Reflective cracking was measured from a reference line that corresponded with the precast flange – CIP interface, as shown in Figure G4. The tabulated crack measurements are outlined in Table G2.

G-4 Figure G4: Location of reference line for measurement of vertical location of cracking in core specimens

G-5 Core Designation Core Characteristics Reflective Crack Characteristics Specimen1 X-Coord.2 Y-Coord.3 Location of Core Side of Longitudinal Joint Core Diameter Distance from Longitudinal Joint or Web/C.I.P. interface Side of Core Depth of Crack4 Width of Crack5 C1-S1 26 0 Longitudinal Joint N/A 2 ¾” S.C.6 N.O.7 N.O.7 N.O.7 N.O.7 C1-S1 134 0 Longitudinal Joint N/A 2 ¾” S.C.6 N.O.7 N.O.7 N.O.7 N.O.7 C1-S1 192 2 Longitudinal Joint North 2 ¾” S.C.6 N.O.7 N.O.7 N.O.7 N.O.7 C1-S1 197.5 0 Longitudinal Joint N/A 2 ¾” S.C.6 1/8” South 1/8” South West East 2 ¾” (up) 1 ¼” (up) A: 0”-1 ¼”; 2: 1 ¼”-2 ¾” 2: 0”-1 ¼” C1-S1 -194.5 0 Longitudinal Joint N/A 1 ¾” ½” North ½” North West East Undefined8 Undefined8 C1-S2 74 0 Longitudinal Joint N/A 1 ¾” N.O.7 N.O.7 N.O.7 N.O.7 C1-S2 146 0 Longitudinal Joint N/A 1 ¾” N.O.7 N.O.7 N.O.7 N.O.7 C1-S2 195.5 0 Longitudinal Joint N/A 1 ¾” N.O.7 N.O.7 N.O.7 N.O.7 C1-S2 198 0 Longitudinal Joint N/A 1 ¾” N.O.7 N.O.7 N.O.7 N.O.7 C2-2.0 193 0 Longitudinal Joint N/A 3 ¾” N.O.7 N.O.7 N.O.7 N.O.7 C2-2.0 193 12 Web/C.I.P. Interface North 3 ¾” 0” 0” West East 3 ½” 1 ½” 2: ¼”-1”; A: 1”-2 ¼”; 2: 2 ¼”-3 ½” 2: 1 ¼” – 1 ½” C2-2.0 193 12 Web/C.I.P. Interface South 3 ¾” 0” North (0”)9 2: (entire length) C2-4.0 76 0 Longitudinal Joint N/A 3 ¾” N.O.7 N.O.7 N.O.7 N.O.7 C2-4.0 76 12 Web/C.I.P. Interface North 3 ¾” N.O.7 N.O.7 N.O.7 N.O.7 C2-4.0 76 12 Web/C.I.P. Interface South 3 ¾” N.O.7 N.O.7 N.O.7 N.O.7 Table G2: Tabulation of characteristics of core samples

G-6 Core Designation Core Characteristics Reflective Crack Characteristics Specimen1 X-Coord.2 Y-Coord.3 Location of Core Side of Longitudinal Joint Core Diameter Distance from Longitudinal Joint or Web/C.I.P. interface Side of Core Depth of Crack4 Width of Crack5 SSMBLG 1 31.5 0 Longitudinal Joint N/A 2 ¾” ¾” East 1 ¼” East North South 7 ½” (up) 6” (up) (North) C: 0”-1”; B: 1”-2”; A: 2”-3 ½”; B: 3 ½”-4 ½”; A: 4 ½”-5”; 2: 5”-7 ½” (South) C: 0”-1”; B: 1”-1 ¼”; 2: 1 ¼”-1 ½”; A: 1 ½”-1 ¾”; C: 1 ¾”-2 ¼”; B: 2 ¼”-2 ¾”; A: 2 ¾”-3 ½”; B: 3 ½”-4 ½”; A: 4 ½”-5”; 2: 5”-6” SSMBLG 1 31.5 12 Web/C.I.P. Interface East 2 ¾” 0” 0” North South 7” (up); 3”(down) 7” (up); 3”(down) A: 0”-¾”; 2: ¾”-7” (up); A: 0”-1”; B: 1”-3” (down) A: 0”-1”; 2: 1”-7” (up); B: 0”-3” (down) SSMBLG 1 31.5 12 Web/C.I.P. Interface West 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 2 33.5 0 Longitudinal Joint N/A 2 ¾” ¾” West ¾” West North South 7 ¼” 7” B: 0”-2 ¼”; A: 2 ¼”-3 ¼”; 2: 3 ¼”-4”; A: 4”-7 ¼” B: 0”-2” A: 2”- 2 ¾”; B: 2 ¾”-3 ¼”; A: 3 ¼”-5 ¾”; 2: 5 ¾”-7” SSMBLG 2 33.5 12 Web/C.I.P. Interface East 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 2 33.5 12 Web/C.I.P. Interface West 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 3 28 0 Longitudinal Joint N/A 2 ¾” ¾” (West) 1” (West) North South 9 ½” 9 ¼” B.P.10: 0”-6 ½”; A: 6 ½”- 8 ½”; 2: 8 ½”- 9 ½” B.P.10: 0”-6 ½”; A: 6 ½”- 7”; B: 7”-8 ½”; A: 8 ½”- 8 ¾”; 2: 8 ¾”- 9 ¼” SSMBLG 3 28 12 Web/C.I.P. Interface West 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 4 31.5 0 Longitudinal Joint N/A 2 ¾” 1” West 1 ¾” West North South 11 ½” 10 ¾” (North) A: 0”- ½”; B: ½”-1 ½”; A: 1 ½”-3 ½”; B: 3 ½”-7 ¼”; 2: 7 ¼”-8 ¼”; A: 8 ¼”-9”; 2: 9”-11 ½” (South) B: 0”-1 ¼”; A: 1 ¼”-1 ¾”; B: 1 ¾”-5”; A: 5”-5 ½”; B: 5 ½”-7 ¼”; 2: 7 ¼”-8”; A: 8”-8 ¼”; 2: 8 ¼”-10 ¾” SSMBLG 4 31.5 12 Web/C.I.P. Interface East 2 ¾” ¼” West ¼” West North South 10 ¼” (up); 3” (down) 10 ¾” (up); 3” (down) BP10: 0”-6”; A: 6”-6 ½”; 2: 6 ½”-10 ¼” (up); B.P.10: 0”-3”; B: 1”-2 ½” (down) B.P.10: 0”-6”; A: 6”-7 ¾”; 2: 7 ¾”-10 ¾” (up); B.P.10: 0”-3” (down) SSMBLG 4 31.5 12 Web/C.I.P. Interface West 2 ¾” 0” 0” North South 10 ¾” 10 ¾” B.P.10: 0”-10 ¼”; 2: 10 ¼”-10 ¾” B.P.10: 0”-9 ½”; A: 9 ½”-10”; 2: 10”-10 ¾” SSMBLG 5 28 1 Longitudinal Joint East 2 ¾” 1 ½” East 1 ¼” East North South 7 ½” 4” B: 0”- ½”; A: ½”-1 ¼”; B: 1 ¼”-1 ¾”; A: 1 ¾”-4”; 2: 4”-7 ½” A: 0”- ½”; B: ½”-1 ½”; A: 1 ½”-2 ¾”; 2: 2 ¾”-4” SSMBLG 5 31.5 0 Longitudinal Joint N/A 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 5 31.5 12 Web/C.I.P. Interface East 2 ¾” 0” 0” North South 7” (up); 1 ½” (down) 7” (up); ¾” (down) 2: 0”-7” (up); 2: 0”-1 ½” (down) 2: 0”-7” (up); 2: 0”-¾” (down) SSMBLG 5 31.5 12 Web/C.I.P. Interface West 2 ¾” 0” 0” North South 1” (down) 1” (down) A: 0”- ½”; 2: ½”-1” A: 0”- ½”; 2: ½”-1”

G-7 Core Designation Core Characteristics Reflective Crack Characteristics Specimen1 X-Coord.2 Y-Coord.3 Location of Core Side of Longitudinal Joint Core Diameter Distance from Longitudinal Joint or Web/C.I.P. interface Side of Core Depth of Crack4 Width of Crack5 SSMBLG 6 32 0 Longitudinal Joint N/A 2 ¾” ¾” East 1 ½” East North South 1 ¾” 2 ¼” 2: 0”-1 ¾” A: 0”-1 ¾”; 2: 1 ¾”-2 ¼” SSMBLG 6 32 12 Web/C.I.P. Interface East 2 ¾” 0” 0” North South 8” (up); 2” (down) 7” (up); 1 ½” (down) (North) B: 0”-2 ½”; A: 2 ½”-4 ½”; 2: 4 ½”-8” (up); B: 0”-1 ½”; 2: 1 ½”-2” (down) (South) B: 0”-1 ¼”; A: 1 ¼”-4 ¼”; 2: 4 ¼”-7” (up); B: 0”-1 ½” (down) SSMBLG 6 32 12 Web/C.I.P. Interface West 2 ¾” 0” 0” North South ¾” ¼” 2: 0”- ¾” 2: 0”- ¼” SSMBLG 7 28.5 0 Longitudinal Joint N/A 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 7 31.5 0 Longitudinal Joint N/A 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 7 31.5 12 Web/C.I.P. Interface East 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 SSMBLG 7 31.5 12 Web/C.I.P. Interface West 2 ¾” N.O.7 N.O.7 N.O.7 N.O.7 1“C1” represents “Concept 1 Bridge Specimen”; “S1” represents “Span 1”; “S2” represents “Span 2”; SSMBLG” represents “Subassemblage Bridge Specimen” 2Distance along the longitudinal joint referenced from side of specimen, (inches) 3Distance perpendicular to and referenced from the longitudinal joint (inches) 4Depth of crack measured up (unless specified otherwise) from the reference line indicated in the Longitudinal Joint Elevation Figure. 5Width of crack, classifications (bold font) defined by Table XY, ranging between depths from the reference point defined on the Bridge Specimen - Longitudinal Joint Elevation Figure. 6“S.C.” indicates that core was split into two half-diameter cores due to a “Saw Cut” made during the demolition of the bridge specimen 7“N.O.” represents “No Reflective Cracks Observed” 8Reflective crack is continuous with shrinkage crack from surface, so beginning and end points are undefined 9Reflective crack lies along precast flange/C.I.P. interface (i.e. reflective crack has no vertical depth) 10“B.P.” represents that this is actually a “Break Plane” between two sections of the core that is likely to have been a reflective crack prior to breaking apart. It is not an in-situ reflective crack.