winter school 2009 - c.ymcdn.com · bearings p/s concrete bridge superstructures ... prestressed...
TRANSCRIPT
www.dot.state.pa.us
Joshua P. Jones EIT
Assistant Structures Control Engineer
WINTER SCHOOL 2014 STRUCTURE CONTROL UNIT
1
www.dot.state.pa.us
TOPICS OF DISCUSSION:
• BEARING PADS (LAMINATED ELASTOMERIC)
• DECK GRADE CALCULATIONS (S.I.P. ANGLES)
• MEASURING DECK THICKNESS
WINTER SCHOOL 2014 STRUCTURE CONTROL UNIT
2
www.dot.state.pa.us
BEARING PADS - SUPPORT SUPERSTRUCTURE, DECK , AND ALLOW STRUCTURE TO MOVE (EXPANSION AND CONTRACTION DUE TO TEMPERATURE)
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
3
www.dot.state.pa.us
PAY CLOSE ATTENTION TO HOW BEARING PADS ARE LAID OUT THESE ARE NOT SET LEVEL… MEANING THEY ARE SET ON A CROSS SLOPE
CROSS SLOPE
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
4
www.dot.state.pa.us
NOTE: THIS CAN OCCUR ON ALL SIDES OF BEARING PAD
BEAM IS SET AND THERE IS A GAP BETWEEN THE BEAM AND BEARING…WHAT SHOULD I DO????
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
5
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
WHEN TO GROUT BEARING PADS
BEARINGS. WHEN ELASTOMERIC BEARINGS ARE USED UNDER BEAMS, DETERMINE IF THERE IS FULL
CONTACT BETWEEN THE BEARING PAD AND BEARING SURFACES JUST AFTER THE BEAMS ARE SET
IN PLACE. TEMPORARILY REMOVE OR RELOCATE WATERPROOFING AND OTHER MATERIAL AS REQUIRED TO
EXPOSE ALL SIDES OF THE PAD. IF A GAP BETWEEN THE PAD AND BEARING SURFACES IS PRESENT,
PROCEED AS FOLLOWS UNLESS THE CONTRACT PLANS INDICATE THAT A LIFT-OFF CONDITION IS EXPECTED
WHEN THE BEAM IS INITIALLY SET ON THE PAD:
GAP THICKNESS > (3/8 INCH). IF A GAP ALONG ANY EDGE OF THE PAD EXCEEDS (3/8 INCH), GRIND
THE BEARING SURFACE OF THE SUBSTRUCTURE TO ELIMINATE THE GAP, EXCEPT GAPS ALONG THE
FRONT EDGE OF THE PAD (EDGE TOWARD THE MIDSPAN OF THE BEAM) WILL BE ALLOWED AS
SPECIFIED IN STEPS 1 AND 2 BELOW. PROVIDE A ROUGH TEXTURED BEARING SURFACE AFTER
GRINDING. VERIFY THAT THE MINIMUM REQUIRED VERTICAL CLEARANCE TO THE BOTTOM OF BEAMS, AS
INDICATED, IS MAINTAINED AFTER GRINDING.
6
www.dot.state.pa.us
Gap Thickness < (3/8 inch) IF GAPS ALONG ANY EDGE OF THE PAD ARE LESS THAN
OR EQUAL TO (3/8 INCH), PROCEED AS FOLLOWS:
GAP ALONG REAR EDGE OF PAD ONLY. IF A GAP OCCURS ANYWHERE ALONG THE
REAR EDGE OF THE PAD (EDGE TOWARD THE END OF THE BEAM), ELIMINATE THE
GAP BY PLACING A LEVELING BED OF POLYMER-MODIFIED MORTAR BENEATH THE
PAD AS SPECIFIED IN SECTION 1080.3(C)2.A.
GAP ALONG SIDE EDGES OF PAD. IF A GAP OCCURS ALONG THE SIDE EDGES OF
THE PAD, AND THERE IS FULL CONTACT AT THE FRONT AND REAR EDGES,
ELIMINATE THE GAP BY PLACING A LEVELING BED OF POLYMER-MODIFIED MORTAR
BENEATH THE PAD AS SPECIFIED IN SECTION 1080.3(C)2.A.
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
7
www.dot.state.pa.us
GAP ALONG FRONT EDGE OF PAD. IF A GAP OCCURS ALONG THE FRONT EDGE
(EDGE TOWARD THE MIDSPAN OF THE BEAM OF THE BEARING PAD), PROCEED AS
FOLLOWS:
STEP 1: DETERMINE THE AREA OF NON-CONTACT BETWEEN THE PAD AND BEAM. IF
THE AMOUNT OF NON-CONTACT IS LESS THAN 20% OF THE PAD AREA,
PROCEED TO STEP 2; OTHERWISE ELIMINATE GAP BY PLACING A LEVELING BED
OF POLYMER-MODIFIED MORTAR BENEATH THE PAD AS SPECIFIED IN SECTION
1080.3(C)2.A.
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
8
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
STEP 1:
GIVEN: PAD SIZE = 10”x 10” TOTAL AREA = 10”x10”=100IN2
NON CONTACT AREA = 3”x10”= 30IN2 THEREFORE: 20% OF 100IN2 = (100IN2 x (20%/100))= 20 IN2 NON CONTACT AREA = 30IN2 > 20IN2 “GROUT PAD” * IF NON-CONTACT AREA WAS 15IN2 < 20IN2 PROCEED TO STEP 2
BRG PAD
10”
10”
BRG
3”
BOX BEAM
9
www.dot.state.pa.us
STEP 2: MEASURE THE MAXIMUM GAP THICKNESS ALONG THE FRONT EDGE AND PROCEED AS FOLLOWS:
SPANS < (100 FEET)
• GAP THICKNESS ≤ (3/32 INCH): LEAVE GAP IN PLACE.
• (3/32 INCH) < GAP THICKNESS ≤ (3/8 INCH): ELIMINATE THE GAP BY PLACING A LEVELING BED OF POLYMER-MODIFIED MORTAR BENEATH THE PAD AS SPECIFIED IN SECTION 1080.3(C)2.A.
SPANS ≥ (100 FEET)
• GAP THICKNESS ≤ (1/8 INCH): LEAVE GAP IN PLACE.
• (1/8 INCH) < GAP THICKNESS ≤ (3/8 INCH): ELIMINATE THE GAP BY PLACING A LEVELING BED OF POLYMER-MODIFIED MORTAR BENEATH
THE PAD AS SPECIFIED IN SECTION 1080.3(C)2.A.
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
10
www.dot.state.pa.us
LEVELING BED OF POLYMER-MODIFIED MORTAR, PLACEMENT PROCEDURE. 1. IMMEDIATELY BEFORE LIFTING BEAM, PREPARE MORTAR ACCORDING
TO THE MANUFACTURER’S RECOMMENDATIONS. DO NOT EXTEND MORTAR BY ADDING COARSE AGGREGATE.
2. LIFT BEAM AS NECESSARY. 3. REMOVE PAD. 4. APPLY A BED OF MORTAR TO THE BEAM SEAT, COVERING AN AREA
APPROXIMATELY 50 MM (2 INCHES) BEYOND THE PERIMETER OF THE BEARING PAD. APPLY THE MORTAR IN A THICKNESS APPROXIMATELY (1/8 INCH) GREATER THAN THE MAXIMUM ACTUAL GAP THICKNESS.
5. PLACE THE PAD ON THE MORTAR. 6. RESET THE BEAM ON THE PAD WHILE THE MORTAR REMAINS PLASTIC. 7. CURE THE MORTAR, AS APPLICABLE, ACCORDING TO THE
MANUFACTURER’S RECOMMENDATION. PLACE MORTAR ACCORDING TO TEMPERATURE RESTRICTIONS RECOMMENDED BY THE MANUFACTURER.
DO NOT PLACE A LEVELING BED OF MORTAR BEFORE THE INITIAL SETTING OF BEAMS.
WHEN TO GROUT BEARING PADS CONT’D
MATERIAL NEEDS TO BE BULLETIN 15 APPROVED!!!
11
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
BRIDGE CONSTRUCTION STANDARDS (BCs) OR PUB. 219
STYROFOAM IS USED TO KEEP CONCRETE FROM ENTERING BEARING AREA WHEN POURING CONTINUITY DIAPHRAGMS SEE BC-788M
12
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
13
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
14
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
HOW TO MINIMIZE GAPS BETWEEN BEARINGS AND BEAMS??? STEP 1: MAKE SURE YOUR BEARING AREA ELEVATIONS ARE WITHIN TOLERANCES AS OUTLINED IN PUBLICATION 408 SECTION 1001.3(K) 9. BEARING AREAS OF SUBSTRUCTURE [STEEL + 0.01 FT. (~ 1/8”), CONCRETE + 0.02 FT. (~ ¼”)] STEP 2: CHECK BEARING AREAS WITH 4FT SMART LEVEL 8 DIFFERENT WAYS
15
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
16
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
17
www.dot.state.pa.us
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
18
www.dot.state.pa.us
ANY QUESTIONS
BEARINGS P/S CONCRETE BRIDGE SUPERSTRUCTURES
PUBLICATION 408 SECTION 1080.3 (C)
19
www.dot.state.pa.us
DECK GRADES 101
DEFINITIONS: BEAM CAMBER - SLIGHT ARCH THAT IS BUILT INTO PRESTRESSED BEAMS BY MEANS OF PRESSTRESSED CABLES ELEVATION - THE DISTANCE ABOVE A KNOWN POINT OR DATUM USUALLY ON GENERAL PLAN AND ELEVATION SHEET PROFILE GRADE - “FINISHED GRADE” BASED ON HORIZONTAL AND VERTICAL ALIGNMENTS CROSS SLOPE - IS A GEOMETRIC FEATURE OF PAVEMENT SURFACES; THE TRANSVERSAL SLOPE [%] WITH RESPECT TO THE HORIZON.
20
www.dot.state.pa.us
DRAINAGE CHECK BEAM CAMBER VERIFY PLAN AND VERTICAL/HORIZONTAL PROFILE GRADES PRIOR TO STEEL TYING AND DECK PLACEMENT
WHY CHECK DECK GRADES?
DECK GRADES 101
21
www.dot.state.pa.us
WHY IS IT IMPORTANT TO MAINTAIN VERTICAL AND HORIZONTAL PROFILE GRADES? SAFETY… THE STRUCTURE WAS DESIGNED PER PLAN. CHANGING GRADES… “MAKING GRADES WORK” IS NOT ALLOWED!!!
DECK GRADES 101
22
www.dot.state.pa.us
BEAMS ARE SET IN PLACE SURVEYORS SHOT LEFT AND RIGHT OF ALL BEAMS AT 10TH POINTS PLAN DOES NOT SHOW ANY LEFT AND RIGHT BEAM ELEVATIONS? HMMMM!!! PLAN DOES SHOW TOP OF DECK ELEVATION AT C/L OF BEAM? HOW DO I CALCULATE FROM C/L OF BEAM TOP OF DECK ELEVATIONS TO LEFT AND RIGHT OF BEAM???
SCENARIO:
DECK GRADES 101
23
www.dot.state.pa.us
BEAM1
BEAM2
BEAM3 LT RT
STAY IN PLACE FORM (S.I.P.) 2 ½” DEPTH
LT RT
DECK GRADES 101
CL BEAM
24
www.dot.state.pa.us
WHAT YOU HAVE TO KNOW BEFORE YOU START
1. STATIONS
2. ELEVATIONS
3. BEAM SIZE
4. DECK THICKNESS
WHAT YOU NEED TO UNDERSTAND
1. SLOPE IS DEFINED AS THE RATIO OF THE "RISE" DIVIDED BY THE "RUN“ THIS IS A GIVEN BY % “CALLED CROSS SLOPE”
2. EXAMPLE 2% CROSS SLOPE (GIVEN ON PLAN)
3. POSITIVE SLOPE IS UPWARD, ADD (+)
4. NEGATIVE SLOPE DOWNWARD, SUBTRACT (-)
DECK GRADES 101
25
www.dot.state.pa.us
CROSS SLOPES BREAK POINTS 1,2,3,4,5
NOT LEVEL ??? TOP OF DECK ELEVATIONS AT CENTER LINE OF BEAM
DECK GRADES 101
26
www.dot.state.pa.us
SPAN 1
THIS IS A GOOD PLACE TO FIND DIMENSIONS!
DECK GRADES 101
27
www.dot.state.pa.us
INFORMATION NEEDED TO CALCULATE DECK GRADES TAKEN
FROM DESIGN DRAWINGS
28
www.dot.state.pa.us
BEAM CAMBER ~ 2.03” (SEE BEAM CAMBER DIAGRAM “A”)
HORIZONTAL LINE
29
www.dot.state.pa.us
DECK GRADES 101
30
www.dot.state.pa.us
FIELD SURVEY DATA
DECK GRADES 101
31
www.dot.state.pa.us
DECK GRADES 101
32
www.dot.state.pa.us
DETAIL: 11 = ACTUAL DECK THICKNESS AT EDGE OF BEAM 13 = HAUNCH THICKNESS 14 & 15 = S.I.P. ANGLE HEIGHT & C/F TO PAN ANGLE
DECK GRADES 101
33
www.dot.state.pa.us
2L/10 “Example Problem” 1 = 337.86’ Finish Elevation at Baseline (taken from design drawings) 2 = Offset from baseline to edge of beam (11’ 6” – 11’) = 6” or 0.5’ (dimensions taken from design drawings) 3 = Roadway or X slope 2% = 2/100= 0.02 (taken from design drawings) (positive grade going up) 4 = Offset from baseline to edge of beam 2’ (half of beam width) – 0.5’ = 1.5’ 5 = Roadway or X slope -2% = -2/100= -0.02 (taken from design drawings) (negative grade going down) 6 = Correction (Offset * X slope) = (0.5’*0.02)+(1.5’*-0.02) = -0.02’ 7 = Theoretical finished grade at beam 337.86’+-0.02’ (Correction) = 337.84’
DECK GRADES 101
34
www.dot.state.pa.us
2L/10 “Example Problem” Cont’d 8 = Anticipated deflections (camber calculations) 0.03’ (Solved for on previous page) 9 = Theoretical finished grade + deflections 337.84’ + .03’ = 337.87’ 10 = Top of Beam Elevation RT = 337.16’ (Field Survey Data) 11 = Actual deck thickness at beam 337.87 (Theoretical finished grade + deflections) -337.16 (Field Survey Data) = 0.71’ 12 = Plan deck thickness = 8” or 0.67’ (Taken from design drawings) 13 = Haunch thickness = 0.71’ (Actual deck thickness at beam) -0.67’ (Plan deck thickness) = 0.04’ 14 =S.I.P. Angle height = -2 ½”or -0.208’ (deck pan thickness) + 0.04’ (Haunch thickness) = -0.16’ 15 = Converts -0.16’ to a fraction for field measuring = 1 15/16”
DECK GRADES 101
35
www.dot.state.pa.us
DECK GRADES 101
This process is the same calculation for each edge of beam
Find base line elevation (CL of beam Top of Deck Elevation)
Determine offset length
Determine cross slope (Convert to decimal – or + grade)
Work from known elevation to edge of beam Use design drawing information
Use survey data
36
www.dot.state.pa.us
BEAM1
BEAM2
BEAM3 LT RT
STAY IN PLACE FORM (S.I.P.) 2 ½” DEPTH
LT RT
DECK GRADES 101
CL BEAM
37
www.dot.state.pa.us
METAL TAB FOR WELDING (S.I.P.) ANGLE
DECK GRADES 101
38
www.dot.state.pa.us
DECK GRADE CALCULATION:
39
www.dot.state.pa.us
1 = FINISH ELEVATION AT BASELINE
2 = OFFSET FROM BASELINE TO EDGE OF BEAM
3 = ROADWAY OR SHOULDER SLOPE (X)
4 = OFFSET FROM BASELINE TO EDGE OF BEAM (ADDITIONAL COLUMN FOR BREAK POINTS)
5 = ROADWAY OR SHOULDER SLOPE (X) (ADDITIONAL COLUMN FOR BREAK POINTS)
6 = CORRECTION (OFFSET * CROSS SLOPE)
7 = THEORETICAL FINISHED GRADE AT EDGE OF BEAM
8 = ANTICIPATED DEFLECTIONS
9 = THEORETICAL FINISHED GRADE AT EDGE OF BEAM + ANTICIPATED DEFLECTIONS
10 = TOP OF DECK ELEVATIONS (FIELD SURVEY)
11 = ACTUAL DECK THICKNESS AT EDGE OF BEAM
12 = PLAN DECK THICKNESS
13 = HAUNCH THICKNESS
14 = S.I.P. ANGLE HEIGHT
15 CUT/FILL TO PAN ANGLE
LEGEND FOR SPREAD SHEET
DECK GRADES 101
40
www.dot.state.pa.us
DECK GRADE CALCULATION:
41
www.dot.state.pa.us
DECK GRADE CALCULATION:
42
www.dot.state.pa.us
DECK GRADE CALCULATION:
43
www.dot.state.pa.us
DECK GRADE CALCULATION FORM:
44
www.dot.state.pa.us
DECK GRADES TABULATED FORM
THIS IS A RARE CASE!!!
45
www.dot.state.pa.us
ANY QUESTIONS
DECK GRADES 101
46
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
MEASURING CONCRETE DEPTH
47
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
The following policy is required to standardize the inspection and documentation procedures for measuring the total deck thickness and the concrete cover over the top mat of reinforcing steel when performing the inspection of bridge deck construction. The inspection measurements must be entered directly into an approved sourced document and included in the permanent project records. It is recommended hat the "Wire Mesh Depth Check" section in the rear of Form CS-472, the Concrete Inspectors Daily Record Book or a "black field book" be used to record all measurements in a format similar to the accompanying example. Report all measurements in a table format (Refer to examples attached). Identify the contract number, structure number, span, pour sequence, starting, ending and test stations, and the location of all pier and deck joints. For long or wide spans, the table can be continued on as many pages as required. ON the left side of the table, indicate the test location stations. Recheck the entire area where grade adjustments are performed and enter the new depth check measurements in the table. Continue to perform the "dry run" inspection until further adjustments are required.
48
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
A."Dry Run" Inspection The "dry run" inspection of the finishing machine should be checked at longitudinal intervals not exceeding 3 m (10 feet) along the length of the bridge deck. Place permanent test station markings on the vertical edge form work to be used as reference points during the concrete placement operation. The stationing should be easily visible. During the "dry run" check, measure the distance from the distance from the bottom of the finishing machine roller(s) to the top of the deck form work to obtain the total deck thickness, and measure the distance from the bottom of the roller(s) to the top mat of reinforcing steel to obtain the depth of concrete cover.
49
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
As a minimum, perform "dry run" depth checks at each 3 m (10 feet) test station, at each end of the transverse span between girders, at grade break points, and adjacent to the outside girder and gutter line of the overhang form work. In addition, measure the total deck width at each test section. During the "dry run" inspection, run the finishing machine transversely along the entire length of all expansion dams, bulkhead forms, etc., to check the grade and profile. Record all measurements directly into the corresponding table location in the source document. Compare the "dry run" measurements against the contract drawings and specifications tolerances. In accordance with Publication 408, Section 1001.3(b)1., "Place reinforcements so the indicated cover does not deviate from position by more than 5 mm (¼ inch)". The contractor must adjust the grade of the screed rail or bar supports (slab bolsters or re-bar chairs) as required to meet specification requirements.
50
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
B. Plastic Concrete Depth Checks During the concrete placement operation, the inspector must perform random plastic concrete depth checks at each 3 m (10 feet) test station. As a minimum, perform three depth checks to measure the total deck thickness and reinforcing steel cover as the same location checked during the inspection of the "dry run". The depth checks should be performed at the location of the finishing machine. Record the measurements directly into the table below the corresponding "dry run" measurements. A wide blade putty knife works well to measure the concrete cover over the top mat of reinforcing steel. The knife blade should be turned perpendicular to the longitudinal direction of the upper reinforcing bar to obtain an accurate measurement.
51
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
A small diameter metal rod works well to measure the concrete cover over the top mat of reinforcing steel. The knife blade should be turned perpendicular to the longitudinal direction of the upper reinforcing bar to obtain an accurate measurement. Different tools can be used to perform the plastic concrete depth checks as long as accurate measurements are obtained. The purpose of performing the plastic concrete depth check is to check that the actual dead load camber deflection of all the girders is occurring as anticipated and in proper relationship to each other. The plastic concrete depth checks also assure that the top mat of reinforcing steel remains in proper position during the concrete placement operation. If significant deficiencies are encountered, the placement operation should be stopped and the situation must be investigated to determine possible causes. If corrective action cannot be taken, a bulkhead form should be placed and the operation stopped.
52
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
C. Hardened Concrete Testing
After the concrete has hardened, and after the completion of the specified
curing period, the depth of the top mat of reinforcing steel may be measured
by use of a pachometer in accordance with PTM No. 419.
Pachometer testing should be performed at deck locations where concrete
cover deficiencies are identified by the plastic concrete depth check
measurement, or as directed by the Engineer.
When required, the total depth of the hardened deck can be determined by
obtaining full depth cores in areas suspected of having deficient deck
thickness. Record all measurements directly into the corresponding area of the
table.
53
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
PA Test Method No. 419
These types of pachometers are capable of measuring the depth of reinforcing steel of 125 mm (5") or more within ± 3 mm (± 1/8") overall accuracy. These are portable units that measure steel reinforcing bar depth by means of magnetic detection of ferrous metal.
54
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
55
www.dot.state.pa.us
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
56
www.dot.state.pa.us
ANY QUESTIONS
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
57
www.dot.state.pa.us
Joshua P. Jones EIT Assistant Structure Control Engineer
Office (717) 783-5162 Cell (717) 943-2597 Email [email protected]
MEASURING DEPTH OF COVER/TOTAL DEPTH OF
PLASTIC CONCRETE ON BRIDGE DECKS
58