STANDARD SPECIFICATIONS FOR CONSTRUCTION OF ROADS AND BRIDGES ON FEDERAL HIGHWAY PROJECTS (FP-14) - page 14

 

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STANDARD SPECIFICATIONS FOR CONSTRUCTION OF ROADS AND BRIDGES ON FEDERAL HIGHWAY PROJECTS (FP-14) - page 14

 

 

Section 566
566.06 Preconstruction Testing.
(a) Field trials. Conduct preconstruction shotcrete field trials before starting shotcrete production.
(1) Test panels. Prepare and cure test panels according to ASTM C1140. Construct steel or
wood test panel forms containing no reinforcement with a minimum width and length of
24 inches (600 millimeters) and a minimum depth of 6 inches (150 millimeters) with either
square or sloped sides.
When shotcrete is to be applied over reinforcement, construct additional steel or wood test panel
forms containing reinforcement with a minimum width and length of 30 inches (750 millimeters)
and a minimum depth of 3 inches (75 millimeters) with either square or sloped sides. Use
reinforcement of the same size and spacing required for the project.
Shoot test panels using the personnel, material, equipment, operating pressures, and mix designs
proposed for the project. Produce test panels for each proposed mix proportion, each anticipated
shooting orientation, and each proposed nozzle operator.
As soon after shooting and is safe to prevent damage, cover and tightly wrap the panels with
material conforming to ASTM C171 or store the panels in a moist room conforming to AASHTO
M 201.
(2) Coring. At least 14 days after shooting, drill at least three 3-inch (75-millimeters) diameter
cores from each test panel according to AASHTO T 24. Moisture condition the cores in sealed
plastic bags or nonabsorbent containers according to Section 7.3 of AASHTO T 24. Deliver
Government cores to the laboratory designated by the CO.
(3) Testing. At least 14 days, but no later than 28 days after shooting; perform and report coating
quality tests including density, boiling absorption and volume of permeable voids according to
ASTM C642. Test at least three samples from each nonreinforced test panel. Samples may consist
of cores or pieces of cores or test panels that are without observable cracks, fissures, or shattered
edges.
Before compressive strength testing, saw or tool the ends of the cores to eliminate projections and
to achieve perpendicularity to the longitudinal axis. At 28 days after shooting, conduct and report
compressive strength tests according to AASHTO T 24. Test at least three cores from each
nonreinforced test panel.
When shotcrete is applied over reinforcement, visually grade at least three cores from each
reinforced test panel according to Section 1.7 of ACI 506.2 at least 14 days, but no later than
28 days after shooting. Between
28 and
48 days, determine the maximum water-soluble
chloride-ion concentration on at least three different test panel samples according to ASTM C1218.
(4) Mix design approval. Submit the test data and results as well as a visual description of each
core to the CO. Include details concerning presence of voids, sand pockets, lamination, and other
inadequacies. Approval of the nozzle operator and mix design will be based on preconstruction
field trials and test results. The test results must meet the requirements of Table 566-1 including the
following:
(a) Compressive strength tests. Calculate the mean compressive core strength of at least three
individual, 3-inch (75-millimeter) diameter cores, taken from the same test panel. The mean of
any three consecutive core strengths must equal or exceed 0.85 f’c with no individual core less
than 0.75 f’c.
505
Section 566
(b) Coating quality tests. Calculate density, boiling absorption, and volume of permeable voids
for each test sample. No individual test may be greater than the maximum permissible values
shown in Table 566-1.
(c) Core grading tests. Calculate the mean core grade from at least three individual core grades.
The mean core grade must not be greater than the maximum permissible value shown in Table
566-1 with no individual core grade greater than 3. When a prequalification test panel is
rejected by the CO, a second panel may be shot. If the nozzle operator’s second mean core
grade is greater than 2.5, that nozzle operator is not permitted to shoot shotcrete on the project.
Core grading is performed during preconstruction testing only as a way of prequalifying nozzle
operators.
(d) Water-soluble chloride ion concentration tests. Calculate the water-soluble chloride ion
concentration for each test sample. No individual test may be greater than the maximum
permissible values shown in Table 566-1. Water-soluble chloride ion analysis is performed
during preconstruction testing only as a way of ensuring corrosion protection of the
reinforcement.
(b) Submissions. Submit field quality control test reports with the test data and results. Include the
following information in the reports:
(1) Date and time of test panel shooting including panel dimensions, size and spacing of
reinforcement, when used, and type of curing;
(2) Test panel identification including panel number, shooting orientation, mix proportions and
nozzle operator;
(3) Date, time, method of panel coring, number of test samples obtained from each panel and
sample preparation methods;
(4) Test sample identification by panel number, sample number and sample dimensions; and
(5) Date, time and types of tests performed.
566.07 Shotcrete Construction. Produce shotcrete according to ACI 506.2 and the following:
(a) Surface preparation. When shotcrete is to be placed over existing concrete or rock, remove loose
or deteriorated material from the existing surface by chipping with pneumatic or hand tools. Cut
shoulders approximately 1 inch (25 millimeters) deep along the perimeter of repair areas on existing
concrete.
Remove curing compound on previously-placed shotcrete surfaces by sandblasting or other approved
method. Maintain prepared surfaces in a clean and dry condition. Install approved depth gauges to
indicate the thickness of the shotcrete layers. Install depth gauges on 6-foot (1.8-meter) centers
longitudinally and transversely with no less than two gauges per increment of surface area to receive
the shotcrete.
Moisten surfaces. When applying shotcrete to previously-placed shotcrete or concrete, provide a
saturated surface dry condition. Soak surfaces with water
2 to
24 hours before application.
Immediately before shotcreting, blow the surfaces free of water.
When applying shotcrete to soil, thoroughly compact the soil to provide a firm foundation. Ensure the
soil lack free surface water before placing shotcrete.
506
Section 566
(b) Reinforcing. Install reinforcing steel when required. Support reinforcing steel so it is not displaced
during shotcrete application. Support the reinforcing steel by anchor studs or bolts installed in the
existing surface. Space anchors at no more than 12 inches (300 millimeters) on overhead surfaces,
18 inches (450 millimeters) on vertical surfaces, and 36 inches (900 millimeters) on top horizontal
surfaces. Use at least three anchors in each individual area. Reinforce areas where shotcrete thickness
exceeds 1½ inches (38 millimeters) with a single layer of either 2 by 2 - W1.2 by W1.2 or 3 by
3 - W1.5 by W1.5 (50 by 50 - MW8 by W8 or 75 by 75 - MW10 by W10) welded wire fabric. Place
fabric parallel to the proposed finished surface. Support fabric at least ½ inch (13 millimeters) from the
existing surface. Provide a minimum 1 inch (25 millimeters) cover over steel items including anchors,
reinforcing bars and wire fabric.
(c) Temperature and weather conditions. Conduct cold and hot weather shotcreting operations
according to Subsection 552.10. Do not perform shotcrete operations during high winds and heavy
rains. Maintain the temperature of the shotcrete mix between 50 and 90 °F (10 and 30 °C). Do not
place shotcrete against frozen surfaces. Place shotcrete when the surface and ambient temperature is at
least 40 °F (5 °C) and rising.
(d) Shotcrete application. Use the same nozzle operator that created acceptable test panels.
(1) Apply shotcrete within 45 minutes of adding cement to the mixture unless an approved
hydration stabilizer is used. If a hydration stabilizer is approved, deliver and place the shotcrete
within the approved design discharge time limit up to 3½ hours maximum.
(2) Limit the layer thickness of each shotcrete application to 2 inches (50 millimeters). Thicker
applications may be approved if the Contractor can demonstrate that no sloughing or sagging is
occurring. If additional thickness is required, broom or scarify the applied surface and allow the
layer to harden. Provide a saturated surface dry condition to the surface before applying an
additional layer.
(3) Remove laitance, loose material, and rebound. Promptly remove rebound from the work area.
(4) Taper construction joints to a thin edge over a distance of at least 12 inches (300 millimeters).
Wet the joint surface before placing additional shotcrete on the joint. Do not use square
construction joints.
(5) Finish shotcrete as directed by the CO.
566.08 Curing Shotcrete. Cure the surface according to Subsection 552.15. For intermediate shotcrete
surfaces or if a stained or finished final surface is required, cure the shotcrete according to Subsection
552.15(b). If no stained or finished surface is required, apply curing compound to the final exposed
shotcrete surface according to Subsection 552.15(c). Maintain shotcrete at a temperature above 40 °F
(5 °C) until shotcrete has achieved a minimum compressive strength of 750 pounds per square inch
(5.2 megapascals).
566.09 Penetrating Stain. Apply according to the manufacturer’s instructions if penetrating stain is used.
566.10 Production Report. Prepare and submit a written report within 24 hours of shotcrete production
and application for each shift. Include the following information:
(a) Quantity and location of shotcrete applied including photos of areas where shotcrete was placed;
507
Section 566
(b) Observations of success or problems of equipment operation, application, final product condition,
and other relevant issues during production and application;
(c) Batch numbers if applicable;
(d) Name of nozzle operator; and
(e) Names and signature of person performing the observation.
566.11 Acceptance. See Table 566-2 for sampling, testing, and acceptance requirements and the quality
characteristic category.
Material for shotcrete will be evaluated under Subsections 106.02 and 106.03. Submit a production
certification with each shipment of hydraulic cement.
The shotcrete mixtures air content, density, density, boiling absorption, and permeable void volume will be
evaluated under Subsections 106.02 and 106.04. Compressive strength will be evaluated under Subsection
106.05. See Table 566-1 for requirements.
The shotcrete placement system will be evaluated under Subsections 106.02 and 106.04.
Measurement
566.12 Measure the Section 566 pay items listed in the bid schedule according to Subsection 109.02 and
the following as applicable:
When measuring shotcrete by the cubic yard (cubic meter), measure in place.
Payment
566.13 The accepted quantities will be paid at the contract price per unit of measurement for the Section
566 pay items listed in the bid schedule, except the shotcrete contract price will be adjusted according to
Subsection 106.05. Payment will be full compensation for the work prescribed in this Section. See
Subsection 109.05.
Payment for shotcrete will be made at a price determined by multiplying the contract price by the
compressive strength pay factor.
508
Section 566
Table 566-2
Sampling, Testing, and Acceptance Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sample
Point of
Split
Reporting
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Source
Aggregate
Measured and
Quality
-
Subsection
1 per
Source of
Yes
Before
quality
tested for
703.16
material type
material
producing
(703.16)
conformance
(106.04 & 105)
Mix Design
Shotcrete
Measured and
All
-
Subsection
1 per
"
Yes
Before
composition
tested for
566.04
mix design
producing
conformance
(106.04)
Production
Aggregate
Measured and
Gradation(1)
-
AASHTO
1 per
Flowing aggregate
Yes,
Before
(fine & coarse)
tested for
T 27 & T 11
day
stream
when
batching
conformance
(bin, belt, discharge
requested
(106.04)
conveyor belt,
or stockpile)
Moisture test
-
AASHTO
"
"
"
"
T 255
509
Section 566
Table 566-2 (continued)
Sampling, Testing, and Acceptance Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sample
Point of
Split
Reporting
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Shotcrete
Measured and
Boiling
-
ASTM
1 set per
Production
See Note
See Note
tested for
absorption
C642
90 yd3
test panels(4)
(5)
(6)
conformance
& permeable
(75 m3),
(106.04)
void volume (2)
but not less
than 1 per job
Density
-
AASHTO
1 per load (3)
Truck mixer
-
Upon
T 121
or agitator (3)
completing
tests
Air content(2)
-
AASHTO
"
"
-
"
T 152 or
T 196
Statistical
Compressive
II
AASHTO
1 set per
Production
See Note
See Note
(106.05)
strength(2)
T 24
30 yd3
test panels(4)
(5)
(7)
(25 m3),
but not less
than 1 per day
(1) Gradation requirements are shown in Table 703-11.
(2) Mixture property requirements are shown in Table 566-1.
(3) Sample according to ASTM C1385. See Table 552-9, Note (4) for allowable reductions in sampling and testing frequencies.
(4) Prepare and cure nonreinforced test panels according to ASTM C1140 for mixture properties testing. Construct steel or wood test panel forms
to a minimum width and length of 24 inches (600 millimeters) and a minimum depth of 6 inches (150 millimeters) with either square or sloped
sides.
(5) Core 3-inch (75-millimeter) diameter samples at least 14 days after the field trial and moisture condition in sealed plastic bags or
nonabsorbent containers according to Section 7.3 of AASHTO T 24. As directed by the CO, deliver Government cores to the designated
laboratory for testing.
(6) Test at least three samples from each nonreinforced test panel at least 14 days, but no later than 28 days after casting. Samples may consist of
cores or pieces of cores as detailed in Subsection 566.06(a)(3).
(7) Test at least three 3-inch (75-millimeter) diameter moisture conditioned cores from each nonreinforced test panel 28 days after casting.
510
Section 567
Section 567. — MICROPILES
Description
567.01 This work consists of furnishing and installing micropiles.
Material
567.02 Conform to the following Subsections:
Centralizers and spacers
722.02(e)
Chemical admixtures
711.03
Hydraulic cement
701.01(a)
Neat hydraulic cement grout
725.13(a)(1)
Reinforcing bars
709.01(b)
Steel pipes
715.05(a)
Water
725.01(a)
Construction Requirements
567.03 Qualifications. Provide a professional engineer, on-site supervisors, and installation personnel
with experience installing and testing micropiles. Submit the following for approval at least 30 days
before starting work:
(a) Names of personnel; and
(b) A résumé for each individual describing their experience on at least five micropile projects of
similar complexity over the past 5 years. Include project names, locations, and contact information
for project owners.
567.04 Submittals. At least 30 days before starting micropile work, submit the following according to
Subsection 104.03:
(a) Start date;
(b) Micropile construction sequence;
(c) Micropile types, sizes, spacings, depths, installation angles, and ultimate strengths for range of
material to be encountered;
(d) Tendons, full moment splices permanent casing, and additional hardware with manufacturer’s
product data sheets, specifications, catalog cuts, and mill certificates;
(e) Manufacturer recommendations for tendon and hardware handling, storing, assembly, and working
temperature ranges. Hollow bar micropiles are unacceptable unless specified or approved by the CO;
(f) Grout type, mix design, mixing equipment, placement procedures, and 7- and 28-day grout
compressive strengths test results;
511
Section 567
(g) Grouting pressure, volume, and location, if post grouting system is used;
(h) Procedures and material for repairing corrosion protection coatings in the field;
(i) Drilling methods and equipment;
(j) Alternative drilling and grouting methods including grout additives;
(k) Additional material needed to achieve required bond capacities such as grout socks;
(l) Methods to ensure borehole stability during excavation and grout placement;
(m) Micropile testing methods and equipment including type and capacity of reaction load system,
drawings, and supporting calculations for structural components of the micropile load test apparatus;
and
(n) Identification number and calibration test certification for each jack, pressure gauge, and
electronic load cell. Clearly indicate the serial number of each component of the testing assembly on
calibration graphs. Submit results from calibration tests conducted by an independent testing
laboratory within the previous 60 days.
567.05 Installation. Stage micropile installation to avoid interconnection or damage to piles with
uncured grout.
Before drilling holes for constructing production micropiles, install pre-production micropiles for
verification load tests. Install verification and production micropiles as follows:
(a) Drilling. Provide equipment capable of drilling soil, boulder colluvium and alluvium, and
bedrock to anticipated depths. Drill micropile holes to the required diameter and length according to
Table 567-1 and the construction schedule and sequence.
If an obstruction prevents the advancement of the pile, abandon the hole and fill the hole with grout.
Drill a new hole at a location approved by the CO. Remove drill cuttings and other loose debris from
the hole.
(b) Casing, reinforcing bar, and splicing. Place reinforcing bars with centralizers according to
Table 567-1. Use centralizers sized to within ½ inch (13 millimeters) of the drill hole diameter.
Construct micropile splices to the required design strength. Align casing joints and reinforcing bar
splices to avoid eccentricity or angles at splices. Locate threaded pipe casing joints at least two
casing outer diameters from bar splices. When multiple bars are used, stagger the bar splices by at
least 12 inches (300 millimeters). If specified or approved, weld according to Subsection 551.11(a).
(c) Grouting. Use a positive displacement grout pump according to Subsection 256.07(b)(1). Use a
neat hydraulic cement grout in one continuous operation. Mix admixtures according to the
manufacturer’s recommendations. Do not use compressed air to directly pressurize the grout.
512
Section 567
Grout the micropile the same day the micropile hole is drilled. Inject grout from the lowest point of
the drill hole until clean, pure grout flows from the top of the micropile. Grout may be pumped
through tremie tubes, hollow stem augers, or drill rods. Ensure complete continuity of the grout
column during all phases of grouting and casing extraction. Control the grout pressures and grout
takes to prevent excessive heave in cohesive soils or fractured formations. Grout the entire pile to the
design cut-off level.
After grouting is complete, fill the grout tube with grout if it will remain in the hole. Allow grout
within the micropiles to attain the minimum design strength before loading.
Observe site conditions in the vicinity of the micropile construction on a daily basis and suspend
operations and notify the CO if:
(1) Ground heave, subsidence, or grout leakage is observed;
(2) Micropile structure is adversely affected; or
(3) Adjacent structures are damaged from drilling or grouting.
Table 567-1
Micropile Construction Tolerances
Micropile Attribute
Allowable Variance
Center of micropile
< 3 inches (< 75 millimeters)
from indicated
plan location or pile spacing
Pile-hole alignment
±2% of design alignment
Top elevation
0 to 1 inch (25 millimeters)
above the design vertical elevation
Center of reinforcing steel
< 0.75 inches (< 20 millimeters)
from pile center
567.06 Testing and Stressing.
(a) Testing equipment. See Subsection 256.08(a).
(b) Stressing. Place stressing equipment over the micropile so that the jack, bearing plates, load
cells, and stressing assembly are axially aligned with the micropile and the micropile is centered
within the equipment. Do not apply loads greater 80 percent of the structural capacity of the
micropile.
Place the reference pressure gauge in series with the pressure gauge and jack so they need not be
unloaded and repositioned during a test. Raise the load from one increment to another. Hold the load
for the required time beginning immediately after the load is applied and record the micropile top
movement to the nearest 0.001 inch (0.025 millimeters) with respect to an independent fixed reference
point. Repump the jack as necessary to maintain a constant load. Monitor the load with a pressure
gauge. If the load measured by the pressure gauge and the load measured by the reference pressure
gauge differ by more than 10 percent, recalibrate the jack, pressure gauge, and reference pressure
gauge.
(1) Verification tests. The CO will designate locations for sacrificial micropiles for verification
tests. Test according to Tables 567-2 and 567-4.
513
Section 567
Table 567-2
Verification Test Load Schedule
Cycle
Load
Hold Time (Minutes)
1
AL
2.5
0.15 DL
2.5
0.30 DL
2.5
0.45 DL
2.5
2
AL
1
0.15 DL
1
0.45 DL
1
0.60 DL
2.5
0.75 DL
2.5
0.90 DL
2.5
1.00 DL
2.5
AL
1
4
0.15 DL
1
1.00 DL
1
1.15 DL
2.5
1.30 DL (Load-hold test)
60*
1.45 DL
2.5
AL
1
5
0.15 DL
1
1.45 DL
1
1.60 DL
1
1.75 DL
2.5
1.90 DL
2.5
2.00 DL
10
(Maximum test load)
1.50 DL
5
1.00 DL
5
0.50 DL
5
AL
5
AL = Alignment load (no greater than 10 percent of DL (0.10 DL) applied to the
pile before setting the movement recording devices. Zero dial gauges after the first
setting of AL).
DL = Unfactored design load.
* Hold the load to within 2 percent and measure and record pile top movement at
1, 2, 3, 4, 5, 6, 10, 20, 30, 50, and 60 minutes.
514
Section 567
A verification test is acceptable based on one of the following results:
(a) Total vertical movement does not exceed 0.375 inches (9.5 millimeters) under DL. If an
AL is used, then the allowable movement will be reduced by multiplying by a factor of
(DL-AL)/DL;
(b) Deflection rate is linear or decreasing and does not exceed 0.040 inch (1 millimeter) per
log cycle time from 1 to 10 minutes or 0.080 inch (2 millimeters) per log cycle time from 6 to
60 minutes under 1.30 times the DL; or
(c) Slope of the load versus deflection (at end of increment) curve does not exceed 0.025 inch
per kip (0.065 millimeters per Newton) at each test load increment.
If the micropile verification is unacceptable, test another to establish the cause and make design
or construction modifications. These modifications may include installing replacement test
micropiles, modifying the installation methods, increasing the bond length, regrouting with
pre-placed re-grout tubes, or changing the micropile type. Submit modifications requiring
changes to the structure and retest the new system as directed by the CO.
Submit micropile geometry, construction, testing details, and verification test results for approval
before installing production micropiles.
Remove verification test micropiles to an elevation below existing ground level.
If construction methods or foundation material change, perform additional verification tests.
(2) Proof tests. The CO will designate production micropiles for proof testing. Test according to
Tables 567-3 and 567-4.
A proof test is acceptable based on one of the following results:
(a) Total vertical movement does not exceed 0.5 inches (13 millimeters) under the unfactored
design load (DL). If an alignment load (AL) is used, then the allowable movement will be
reduced by multiplying by a factor of (DL-AL)/DL;
(b) Deflection rate is linear or decreasing and does not exceed 0.040 inch (1 millimeter) per
log cycle time from 1 to 10 minutes or 0.080 inch (2 millimeters) per log cycle time from 6 to
60 minutes under 1.30 times the unfactored design load (1.30 DL); or
(c) Slope of the load versus deflection (at end of increment) curve does not exceed 0.025 inch
per kip (0.065 millimeters per Newton) under the maximum test load (1.60 DL.)
If a proof-tested micropile is unacceptable, proof test another micropile in the immediate
vicinity. Establish the cause and make design or construction modifications for future piles.
Submit modification requiring changes to the structure for approval.
515
Section 567
Table 567-3
Proof Test Load Schedule
Minimum Hold
Load
Time (Minutes)
AL
2.5
0.15 DL
2.5
0.30 DL
2.5
0.45 DL
2.5
0.60 DL
2.5
0.75 DL
2.5
0.90 DL
2.5
1.00 DL
2.5
1.15 DL
2.5
1.30 DL (Load-hold test)
10*
1.45 DL
2.5
1.60 DL (Maximum test load)
2.5
1.30 DL
4
1.00 DL
4
0.75 DL
4
0.50 DL
4
0.25 DL
4
AL
4
AL = See alignment load note in Table 567-2.
DL = Unfactored design load.
* Hold the load to within 2 percent and measure and record pile top movement at
1, 2, 3, 4, 5, 6, and 10 minutes. If the movement measured between 1 and 10
minutes exceeds 0.04 inches
(1 millimeter), continue holding the load and
measure and record pile movement at 20, 30, 50, and 60 minutes.
567.07 Test Results and Reporting. Provide preliminary results for each micropile tested to the CO
before testing personnel leave the site. Submit detailed verification and proof test load and deflection
data in a tabular format. Submit a graph that plots total micropile top movement versus load, the A-line,
and the B-line. The A-line is defined as 0.8 multiplied by the theoretical free test length elastic
elongation. The B-line is defined as the theoretical free test length elastic elongation plus 0.50 multiplied
by the theoretical bond length elastic elongation. Allow 5 days for the CO to conduct a review of the
data and approve micropile installation.
567.08 Acceptance. See Table 567-4 for sampling, testing, and acceptance requirements.
Material for micropiles will be evaluated under Subsection 106.03. Submit a production certification
with each shipment of structural steel and casing.
Construction of micropiles will be evaluated under Subsections 106.02 and 106.04.
Reinforcing bars will be evaluated under Section 554.
516
Section 567
Measurement
567.09. Measure the Section 567 pay items listed in the bid schedule according to Subsection 109.02
and the following as applicable:
When production micropiles are measured by the linear foot (meter); measure from the plan top
elevation to the approved tip elevation.
Do not measure failed proof or verification tests or additional tests to verify alternative micropile
installation methods proposed by the Contractor.
Payment
567.10. The accepted quantities will be paid at the contract price per unit of measurement for the Section
567 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in
this Section. See Subsection 109.05.
517
Section 567
Table 567-4
Sampling, Testing, and Acceptance Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sampling
Point of
Split
Reporting
Remarks
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Mix Design
Neat
Measured and
Compressive
-
ASTM
1 per
Source
Yes
Before
hydraulic
tested for
strength
C942
mix
of
producing
cement
conformance
design
material
grout
(106.04)
(725.13)
Production
Neat
Measured and
Density
-
AASHTO
1 per
Mixer
No
24
hydraulic
tested for
T 133
5 piles
hours
cement
conformance
Upon
ASTM
Point of
grout
(106.04)
Flow
-
"
"
completion
C939
discharge
(725.13)
of test
Compressive
-
ASTM
1 set
Grout
"
strength
C942
of
plant
3 samples(1)
Verification
"
Performance
-
Subsection
All
Installation
No
5
test
567.06(b)(1)
days
micropile
Proof
"
Performance
-
Subsection
1 in 20
"
"
"
test
567.06(b)(2)
micropile
(1) From each grout plant per day of operation or per five micropiles, whichever occurs more frequently.
518
Section 568
Section 568. — HIGH PERFORMANCE CONCRETE
Description
568.01 This work consists of furnishing, placing, finishing, and curing high performance concrete (HPC)
in bridge decks, approach slabs, and other structural elements.
In addition to the Section 552 structural concrete properties, HPC conforms to performance characteristics
for the following:
(a) Maximum chloride permeability. Total charge in coulombs passed over a specified period of
time according to AASHTO T 277, except as modified in Table 568-2.
(b) Drying shrinkage. Drying shrinkage in microstrains according to ASTM C157, except as
modified in Table 568-2.
Material
568.02 Conform to the following Subsections:
Air-entraining admixtures
711.02
Chemical admixtures
711.03
Coarse aggregate for concrete
703.02
Color coating
725.15
Concrete coloring agents
711.05
Curing material
711.01
Fine aggregate for concrete
703.01
Hydraulic cement
701.01
Pozzolans
725.04
Reinforcing fibers
725.17
Water
725.01(a)
Construction Requirements
568.03 Qualifications. Provide an on-site supervisor with experience completing of at least two HPC
projects of similar complexity within the last 3 years.
568.04 Composition (Concrete Mix Design). Design and produce concrete mixtures that conform to the
following:
(a) Tables 552-3 and 568-1; and
(b) Chapter 5 of ACI 318, Building Code Requirements for Structural Concrete and Commentary for
determining required average compressive strength (f’cr).
Submit HPC mix designs on FHWA Form 1608, 552 Structural Concrete Mix Design Submittal.
519
Section 568
Verify mix designs with trial mixes prepared according to ACI 318 from proposed sources or with
previous concrete production data for the mixture design submitted from proposed sources. Verify the
performance characteristics and plastic properties in Table 568-1. Submit written concrete mix designs for
approval at least 36 days before production. Include the items listed in Subsection 552.03 in each concrete
mix design submittal.
Begin production only after the mix design is approved.
Furnish a new mix design for approval if there is a change in a source of material source or when the
fineness modulus of the fine aggregate changes by more than 0.20.
568.05 Strength-Maturity Relationship. For the approved concrete mix design and anticipated weather,
develop a strength-maturity relationship according to AASHTO T 325. Submit the relationship for
approval at least 14 days before production. Develop a new relationship if changes in the mix constituents,
hydration stabilizer dosage, or weather affect the relationship.
Provide a concrete maturity meter for the test section and production that:
(a) Conforms to AASHTO T 325;
(b) Is rugged, waterproof, and able to withstand the construction environment;
(c) Operates without an external power source for at least 14 days;
(d) Collects and stores temperature and maturity data for at least 14 days; and
(e) Determines equivalent maturity hours according to the Arrhenius function.
568.06 Test Section. For bridge decks, approach slabs, and other flatwork, construct a 9-foot by 9-foot
by 8-inch (3-meter by 3-meter by 200-millimeter) test section. For other structural elements, construct a
3- by 3- by 3-foot (1- by 1- by 1-meter) test section. Use the approved concrete mix design and the same
methods of handling, placing, monitoring, finishing, curing, and cleaning as intended for production
placement. Sample and test for Table 568-1 conformance.
Use the strength-maturity relationship developed for the approved mix design to determine in-place
concrete compressive strength. Verify that the test section concrete has a similar time temperature
relationship.
Begin production only after the test section is evaluated and accepted.
520
Section 568
Table 568-1
Performance Characteristics and Plastic Properties of HPC
Property
Specification
Chloride permeability,
1,500 coulombs
AASHTO T 277, except
maximum at 28 days
as modified in Table 568-2
Drying shrinkage,
500 microstrains
ASTM C157, except
maximum
as modified in Table 568-2
Compressive strength,
5,000 pounds per square inch
AASHTO T 22
(34.5 MPa) minimum at 28 days
Water/cementitious material ratio
0.45 maximum
Aggregate size
¾ inches (19 millimeters)
nominal maximum
Total cementitious content (1)
517 to 846 pounds per cubic yard
(307 to 502 kilograms per cubic meter)
Slump (2), AASHTO T 119
2 to 8 inches (50 to 200 millimeters)
Air content (3),
AASHTO T 152 or
See Subsection 552.03
AASHTO T 196
Sulfate resistance
AASHTO M 240, Type IP(MS) or
Type IS(< 70)(MS)
(use Type II cement (4)(5)
per AASHTO M 85)
Water-soluble chloride ion content,
0.15 percent by mass of cement maximum
ASTM C1218 (6)
for reinforced concrete
0.06 percent by mass of cement maximum
for prestressed concrete
(1) The total cementitious content includes portland cement and all pozzolans added to the
concrete mixture (such as ground granulated blast furnace slag, fly ash, and silica fume).
(2) Slump can be adjusted using a high range water reducer (superplasticizer) as long as the
maximum water/cementitious material ratio is not exceeded. Include the water contained in the
aggregates above the amount of absorbed water in the calculation of the water/cementitious
material ratio.
(3) If the plastic air content is low when the concrete arrives on-site, additional air-entraining agent
may be added to the concrete and mixed provided that 300 revolutions of the mixer has not been
exceeded.
(4) For seawater exposure, other portland cement types are permitted if the tricalcium aluminate
(C3A) content is 10 percent or less and the water/cementitious material ratio is 0.40 or less.
(5) Other cement types are permitted if the C3A content is less than 8 percent.
(6) Determine the water-soluble chloride ion content contributed from the ingredients including
water, aggregates, cementitious material, and admixtures between ages 28 and 42 days.
568.07 Handling and Storing Material. See Subsection 552.04.
568.08 Measuring Material. See Subsection 552.05.
568.09 Batching Plant, Mixers, and Agitators. See Subsection 552.06.
521
Section 568
568.10 Mixing. See Subsection 552.07.
When required, add reinforcing fibers to the concrete mixture following manufacturer’s
recommendations. Mix until uniformly distributed in the concrete mixture. Gradually add fibers to the
concrete mixture.
568.11 Delivery. See Subsection 552.08, except do not use nonagitating equipment.
If reinforcing fibers reduce the workability, do not add additional water to concrete mixture. If approved
by the CO, add a water reducing admixture conforming to AASHTO M 194 or a high range water
reducing admixture.
568.12 Quality Control of Mix. See Subsection 552.09.
Deliver and sample concrete according to Subsection 552.09(b), except as modified in Table 568-2.
568.13 Temperature and Weather Conditions. Before placement, maintain the temperature of the
concrete between 50 and 80 °F (10 and 27 °C).
Install maturity meter probes and monitor concrete temperatures according to AASHTO T 325. Monitor
the temperature differential from the center of the concrete mass to its surface. Provide internal cooling,
external heating, or insulation to insure the temperature differential does not exceed 35 °F (20 °C)
during placing, curing, cooling, form stripping, and after curing ends.
During curing, maintain the temperature of the concrete mass interior below 140 °F (60 °C) and
temperature of the outer most surfaces above 45 °F (7 °C).
(a) Cold weather. See Subsection 552.10(a), except as follows:
(1) Place concrete for flatwork only when the ambient air temperature is 45 °F (7 °C) and rising.
Place concrete for other structural elements only when the ambient air temperature is 35 °F
(2 °C) and rising;
(2) Protect concrete until the concrete maturity data indicates that minimum compressive strength
is achieved; and
(3) At the end of the protection period, start the cooling process when the average wind speed is
less than 10 miles (16 kilometers) per hour as measured 3 feet (1 meter) from the concrete surface.
(b) Hot weather. See Subsection 552.10(b), except as follows:
(1) Place concrete when the ambient air temperature is less than 85 °F (30 °C.);
(2) Do not remove curing material until the concrete maturity data indicates that minimum
compressive strength is achieved and the moist curing period is complete; and
(3) Do not remove curing material until the calculated evaporation rate is less than 0.15 pounds
per square foot (0.74 kilograms per square meter) per hour as determined by Figure 552-1.
522
Section 568
(c) Evaporation. Do not place concrete if the predicted evaporation rate, determined without
fogging and other protective measures, is greater than 0.15 pounds per square foot (0.74 kilograms
per square meter) per hour as determined by Figure 552-1. For wind speed, use an anemometer with
full scale accuracy to within 4 percent and for relative humidity, use a psychrometer or hygrometer
with full scale accuracy to within 2 percent. Measure wind speed and relative humidity 24 inches
(600 millimeters) above the concrete surface.
Before placing, install and demonstrate fogging equipment for approval and identify personnel to
operate the equipment.
While placing, finishing, and curing surfaces; take care to prevent crusting and plastic shrinkage
cracking. Do not allow the surface of the freshly placed concrete to dry. Use fogging, windbreaks
and other protective measures as necessary to limit the expected evaporation rate to less than
0.1 pound per square foot (0.5 kilogram per square meter) per hour as determined by Figure 552-1.
Use pressure sprayers or atomizers to maintain a moist surface. Do not apply moisture under
pressure directly to the concrete surface. Do not allow water to accumulate to cause a flow or wash
on the concrete surface. Continue fogging the concrete surface until finishing operations are
complete and the surface is covered. Do not wait until final set to cover the concrete surface.
(d) Rain. Protect the concrete from rain during and after placement.
568.14 Handling and Placing Concrete. See Subsection 552.11.
568.15 Construction Joints. See Subsection 552.12.
568.16 Expansion and Contraction Joints. See Subsection 552.13.
568.17 Finishing Plastic Concrete. See Subsection 552.14.
568.18 Concrete Curing. Begin curing within 4 hours after the concrete achieves final set.
(a) Flatwork curing. Use the water method according to Subsection 552.15(b). Apply soaker hoses
or other approved methods to keep the coverings saturated. Keep the concrete saturated and covered
for the entire curing period.
(b) Structural elements. Use a combination of the forms in-place method according to Subsection
552.15(a) and the water method according to Subsection 552.15(b). If forms are stripped or loosened
before the end of the curing period, complete the remainder of the curing using the water method.
During hot and cold weather, cure until the in-place concrete compressive strength reaches the minimum
shown in Table 568-1 at measured locations according to AASHTO T 325. At other times, cure until the
in-place compressive strength reaches 80 percent of the minimum shown in Table 568-1. Cure flatwork
at least 14 days and structural elements at least 10 days.
If directed by the CO after curing, clean staining or efflorescence to provide a uniform color to the
concrete surface.
568.19 Texturing Driving Surfaces. After curing, produce a skid-resistant surface by saw cutting
grooves according to Subsection 552.14(c)(1).
523
Section 568
568.20 Acceptance. See Table 568-2 for sampling, testing, and acceptance requirements and the quality
characteristic category.
Material for HPC will be evaluated under Subsections
106.02 and 106.03. Submit a production
certification with each shipment of cementitious material.
The concrete mixture’s slump, air content, density, and temperature will be evaluated under Subsections
106.02 and 106.04.
Concrete compressive strength will be evaluated under Subsection 106.05. The lower specification limit
is the minimum required compressive strength at 28 days (fc’) shown in Table 568-1. Remove and
replace concrete represented by cylinders having a compressive strength less than 90 percent of the
minimum 28-day compressive strength (fc’).
Maximum chloride permeability will be evaluated under Subsection 106.05. The upper specification
limit is the maximum specified chloride permeability value at 28 days shown in Table 568-1.
Drying shrinkage will be evaluated under Subsection 106.04. The upper specification limit is the
maximum shown in Table 568-1. If the concrete mixture contains 1.5 gallons per cubic yard (7.5 liters
per cubic meter) of an approved shrinkage reducing admixture, drying shrinkage testing is not required
and drying shrinkage will be evaluated under Subsection 106.03.
Construction (including batching, placing, finishing, and curing concrete) of HPC structures will be
evaluated under Subsections 106.02 and 106.04.
Falsework and forms will be evaluated under Section 562.
Measurement
568.21 Measure the Section 568 pay items listed in the bid schedule according to Subsection 109.02 and
the following as applicable:
When measuring HPC by the cubic yard (cubic meter), measure in the structure.
Payment
568.22 The accepted quantities will be paid at the contract price per unit of measurement for the Section
568 pay items listed in the bid schedule, except the HPC contract price will be adjusted according to
Subsection 106.05. Payment will be full compensation for the work prescribed in this Section. See
Subsection 109.05.
Payment for HPC will be made at a price determined by multiplying the contract price by the lower of
the two pay factors determined for compressive strength or chloride permeability.
524
Section 568
Table 568-2
Sampling and Testing Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sampling
Point of
Split
Reporting
Remarks
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Source
Aggregate
Measured and
Quality
Subsections
1 per
Source of
Yes
Before
(703.01 &
tested for
703.01 &
material
material
producing
703.02)
conformance
703.02
type
(106.04 & 105)
including ASR
requirements
Mix Design
Concrete
Measured and
All
Subsection
1 per
"
Yes
"
composition
tested for
568.04
mix
conformance
design
(106.04)
Production Start-up (test section)
HPC
Measured and
Maximum(2)
AASHTO
1 set per
Discharge
Yes
Upon
tested for
chloride
T 277
test
stream
completing
conformance
permeability
placement
at point of
tests
(106.04) (1)
placement
Compressive
AASHTO
"
"
"
"
strength(3)
T 23 & 22
Drying(4)(5)
ASTM
"
"
"
"
shrinkage
C157
Production
Produced
Measured and
Gradation
AASHTO
1 per
Flowing
Yes
Before
aggregate
tested for
T 27 & T 11
day
aggregate
batching
(fine &
conformance
stream (bin,
coarse)
(106.04)
belt, discharge
conveyor belt,
or stockpile)
Fineness
AASHTO
"
"
"
modulus
T 27
Moisture test
AASHTO T 255
"
"
"
525
Section 568
Table 568-2 (continued)
Sampling and Testing Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sampling
Point of
Split
Reporting
Remarks
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Production (continued)
HPC
Measured and
Density
AASHTO
1 per
Point of
No
Upon
tested for
T 121
load
discharge
completing
conformance
tests
(106.04)
Air content
AASHTO
"
"
No
"
T 152 or
AASHTO
T 196
Slump(6)
AASHTO
"
"
No
"
T 119
Temperature
ASTM
"
"
No
"
C1064
Drying(4)(5)
ASTM
1 set per
"
"
"
shrinkage
C157
75yd3
(57 m3)
HPC
Statistical
Maximum
II
AASHTO
1 set per
Discharge
Yes
Upon
(106.05)
chloride
T 277
30 yd3
stream at
completing
permeability(2)
(23 m3),
point of
tests
but not less
placement
than 1 per day
Compressive
II
AASHTO
"
"
"
"
strength(7)
T 23 & T 22
526
Section 568
Table 568-2 (continued)
Sampling and Testing Requirements
(1) Sample according to AASHTO R 60, except composite samples are not required.
(2) Cast at least three 4- by 8-inch (100- by 200-millimeter) maximum chloride permeability cylinders per set and carefully transport the cylinders to the job site
curing facility. Cure the cylinders for 7 days according to AASHTO M 201. Then cure at 100 °F ± 10 °F (38 °C ± 5 °C) in saturated lime water until AASHTO
T 277 sample conditioning begins. Have the testing done at 28 days in an independent laboratory that is qualified to perform the testing and is approved by the CO.
The set test result is the average of the measurements on three cylinders cast from the same load. If pigment is used in the concrete mixture, sample concrete at the
batch plant before and after adding pigment. Test at least three specimens with and without pigment. Determine the average difference between the pigmented and
nonpigmented test results. Adjust production test result by the average difference. Report both initial and adjusted test results.
(3) Cast at least eighteen 4- by 8-inch (100- by 200-millimeter) compressive strength cylinders per set and carefully transport the cylinders to the job site curing
facility. Have the testing done at 1, 3, 7, 14, and 28 days in an independent laboratory that is qualified to perform the testing and is approved by the CO. A single
compressive strength test result is the average result from three cylinders cast from the same load.
(4) Drying shrinkage testing is not required if the concrete mixture contains 1.5 gallons per cubic yard (7.5 liters per cubic meter) of an approved shrinkage
reducing admixture.
(5) If testing is required, use 3- by 3- by 11-inch (75- by 75- by 275-millimeter) prisms for drying shrinkage specimens. Cast at least three drying shrinkage prisms
per set and carefully transport the prisms to the job site curing facility. Moist the prisms for the duration of the specified moist curing period for HPC elements.
Have the testing done in an independent laboratory that is qualified to perform the testing and is approved by the CO. The zero measurement for percent drying
shrinkage is the initial measurement taken at demolding of the specimens at 23½±½ hours after introduction of mixing water to the concrete mixture. Measure
percent drying shrinkage at the end of specified moist curing period for the structural elements, 1, 4, 7, 14, 28, and 56 days after the end of the specified field moist
curing period. Drying shrinkage 28 days after the termination of moist curing (28 days drying) cannot exceed 60 percent of the maximum specified value. The set
drying shrinkage test result is the average result from three prisms cast from the same load.
(6) If reinforcing fibers are used at an addition rate greater than 0.3 percent by volume, measure slump at the batch plant before the addition of fibers.
(7) Cast at least six 4- by 8-inch (100- by 200-millimeter) compressive strength cylinders per set and carefully transport the cylinders to the job site curing facility.
Test three cylinders at 28 days. Use the remainder of cylinders as designated by the CO.
527
Section 569
Section 569. — CONCRETE OVERLAYS FOR BRIDGE DECKS
Description
569.01 This work consists of furnishing, placing, finishing, and curing concrete for bridge deck overlays
including the preparation of existing deck surfaces.
Concrete overlay class is designated high performance concrete overlay (HPC(O)) or latex-modified
concrete (LMC) according to Table 569-1.
Material
569.02 Conform to the following Subsections:
Air-entraining admixtures
711.02
Chemical admixtures
711.03
Coarse aggregate for concrete
703.02
Concrete coloring agents
711.05
Fine aggregate for concrete
703.01
Hydraulic cement
701.01
Latex emulsion admixture
711.04
Pozzolans
725.04
Reinforcing fibers
725.17(b)
Water
725.01(a)
Construction Requirements
569.03 Qualifications. Provide an on-site supervisor with experience completing of at least two overlay
projects with the specific overlay class within the last 3 years.
569.04 Composition (Concrete Mix Design). Design and produce concrete overlay mixtures that
conform to following:
(a) Table 569-1 for the class specified; and
(b) Chapter 5 of ACI 318, Building Code Requirements for Structural Concrete and Commentary for
determining required average compressive strength (f’cr).
528
Section 569
Table 569-1
Composition of Concrete
Property
Performance Characteristics
Total
Maximum
Slump
Air
Course
Maximum
Maximum
Average
Minimum
Cementitious
Water to
inches
Content
Aggregate
Chloride
Dry
Bond
Compressive
Concrete
Material
Cementitious
(mm)
(%)
Size
Permeability
Shrinkage(5)
Strength at
Strength
Overlay
Content(1)
Material
Number
AASHTO
ASTM
14 Days
AASHTO
Class
pounds/yard3
Ratio(3)
AASHTO
T 277
C157
ASTM
T 22
(kg/m3)
M43 (4)
coulombs
microstrains
C1583
pounds/inch2
pounds/inch2
(megapascals)
(megapascals)
HPC(O)
564 to 846
0.45
2 to 8
Table
#7, #78, #8
1,500
500
150
4,500
(335 to 502)
(50 to 200)
552-2
(1.03)
(31)
LMC(2)
564 to 846
0.45
2 to 8
3.0 to 10.0
#7, #78, #8
1,500
150
4,000
(335 to 502)
(50 to 200)
(1.03)
(28)
(1) The total cementitious material content includes portland cement and all pozzolans added to the concrete mixture (such as ground granulated blast furnace
slag, fly ash, and silica fume). Meet the requirements of Table 552-3.
(2) Add 3.5 gallons (15 liters) of latex emulsion per 94 pounds (43 kilograms) of cement.
(3) Include the water contained in the aggregates above the amount of absorbed water in the calculation of the water-to-cementitious material ratio.
(4) Meet the processing requirements of AASHTO M 43, Table 1 - Standard Sizes of Processed Aggregate. Do not use gravel or alkali-silica reactive
aggregates.
(5) Dry shrinkage testing is not required if the concrete mixture contains 1.5 gallons per cubic yard (7.5 liters per cubic meter) of an approved shrinkage
reducing admixture.
529
Section 569
Submit concrete overlay mix designs on FHWA Form 1608, 552 Structural Concrete Mix Design
Submittal.
Verify the mix designs with trial mixes prepared according to ACI 318 from proposed sources or with
previous concrete production data for the mixture submitted from proposed sources. Verify the
performance characteristics in Table 569-1. Submit written concrete mix designs for approval at least
36 days before production. Include the items listed in Subsection 552.03(a) through (y) in each mix design
submittal.
Furnish a new mix design for approval if a source of material changes or if the fine aggregate fineness
modulus changes by more than 0.20.
569.05 Strength-Maturity Relationship. See Subsection 568.05.
569.06 Surface Preparation. Remove asphalt, asphalt membranes, and concrete overlays without
damaging the concrete bridge deck. Use micro milling machine to remove existing overlays. Sound the
bridge deck according to ASTM D4580 to identify unsound concrete in deck. Do not perform surface
preparation within 6 feet (1.8 meters) of a new overlay until 48 hours after its placement. Submit a repair
plan for approval by the CO that includes the following:
(a) Concrete repairs. Determine the depth of concrete cover over the existing reinforcement using a
covermeter or ground penetrating radar. Remove unsound concrete according to Subsections
203.04(b) and 203.04 (c). Prepare and repair concrete according to Section 502.
Remove at least 1 inch (25 millimeters) of concrete around exposed or unbounded reinforcement.
Remove and replace deteriorated reinforcement.
Within 24 hours before placing repair concrete, clean exposed concrete surfaces, reinforcement, and
structural steel of rust and foreign material by abrasive shot blasting and pressurized water flushing.
In repair areas larger than 2 square feet (0.19 square meters) with exposed reinforcement, install
pre-packaged zinc sacrificial anodes on the reinforcement according to manufacturer’s
recommendations.
(1) In areas larger than 2 square feet (0.19 square meters) and smaller than 4 square feet
(0.37 square meters), install a pair of anodes on the reinforcement. Install the anodes at opposite
sides of the repair and within 6 inches (150 millimeters) of the edge of the repair; and
(2) In areas 4 square feet (0.37 square meters) and larger, install an additional pair of anodes for
each incremental 4-square foot (0.37-square meter) increase in the repair area.
Use a concrete mixture conforming to Table 552-1 Class C(AE) concrete to fill the repair area. In
repair areas not containing anodes, an approved high strength concrete patching compound placed
according to the manufacturer’s recommendations may be used. Fill repair areas level with the
surface of the surrounding concrete deck.
Cure repair areas according to Subsection 552.15(b) until the concrete obtains a compressive
strength of 3000 pounds per square inch (21 megapascals).
530
Section 569
(b) Surface profiling. Provide a minimum profile of 1/16 inch (1.6 millimeters) and a maximum of
¼ inch (6 millimeters) on the substrate concrete to bond with the concrete. Use hydrodemolition
according to Section 560 or a micro milling machine.
After surface profiling approval and within 36 hours of expected overlay placement, shotblast and
pressure wash the substrate concrete. Use a potable water source with a minimum water pressure of
4000 pounds per square inch (55 megapascals). Remove concrete laitances, oils, fuels, and other
foreign and loose material detrimental to achieving a sufficient bond. Capture debris from
shotblasting and pressure washing and properly dispose of it off site. Cover the prepared surface
with polyethylene sheeting to prevent contamination.
(c) Saturation. Thoroughly water-soak the clean concrete surface for at least 24 hours before
placing the overlay concrete. Do not use burlap. Remove puddles of standing water using a vacuum
or other approved equipment. Do not use a blower or compressed air to remove water.
569.07 Test Section. Prepare the substrate concrete surface using the same methods intended for the
overlay placement. Construct a 9- by 9-foot (3- by 3-meter) test section on the substrate concrete at the
same thickness as the overlay. Use the approved concrete mix design and the same methods of handling,
placing, finishing, and curing intended for actual placement. Sample and test for Table
569-1
conformance.
Demonstrate the maturity meter operation. Use the strength-maturity relationship developed for the
approved mix design to determine in-place compressive strength. Verify that the test section concrete has a
similar time temperature relationship. Demonstrate methods for conforming to temperature requirements
in Subsection 569.14.
Demonstrate methods for cleaning staining or efflorescence to provide uniform color on the concrete
surface.
Begin production only after the test panel is evaluated and accepted.
569.08 Handling and Storing Material. See Subsection 552.04.
Protect latex emulsion from freezing and prolonged exposure to temperatures in excess of 85 °F (29 °C).
Store containers of latex admixture at the bridge site for a period not to exceed 10 days.
569.09 Measuring Material. See Subsection 552.05.
569.10 Batching Plant, Mixers, and Agitators. See Subsection 552.06 and the following:
(a) Class HPC(O). Furnish ready-mixed concrete produced and delivered according to AASHTO
M 157.
(b) Class LMC. Furnish proportioning and mixing equipment with an integral mobile unit with
continuous mixing capability. Furnish a mixer with the following capabilities:
(1) Capable of producing at least
6.0 cubic yards
(4.6 cubic meter) of concrete without
recharging;
531
Section 569
(2) Equipped with a cement metering device and recording meter accurate within a tolerance of
minus 1 to plus 3 percent and with a ticket printout device to record the cement quantity added to
the mix;
(3) Equipped with a latex tank with a standpipe marked in gallons (liters) and a latex metering
device accurate within a tolerance of minus 1 to plus 2 percent;
(4) Equipped with a water flow control and flow indicator accurate within a tolerance of
2 percent in the range of expected use that is readily adjustable to provide for minor variations in
aggregate moisture content;
(5) Equipped with controls to regulate the quantity of other components required to produce the
specified mix; and
(6) Capable of discharging the mixture through a conventional chute directly in front of the
finishing machine.
Calibrate LMC equipment with material for the approved mix design within 6 months of the
placement date. Keep the equipment maintained, calibrated, clean, and free of partially dried or
hardened material.
569.11 Mixing. See Subsection 552.07 and the following:
Add reinforcing fibers to the concrete mixture following the manufacturer’s recommendations. Add
fibers to the concrete mixture gradually to ensure the fibers are uniformly distributed throughout the
concrete mixture.
569.12 Delivery. See Subsection 552.08, except do not use nonagitating equipment.
(a) Class HPC(O). If reinforcing fibers reduce workability, do not add additional water to the
concrete mixture. Adjust workability using admixtures from the approved mix design.
If the air content is low when the concrete arrives on-site, add air-entraining agent and mix.
(b) Class LMC. Deliver concrete through the conventional chute of an integral mobile volumetric
mixer directly in front of the finishing machine.
569.13 Quality Control of Mix. See Subsection 552.09, except as modified in Table 569-2.
569.14 Temperature and Weather Conditions. Before placement, maintain the temperature of the
overlay concrete mixture between 45 and 80 ºF (7 and 27 ºC).
Install maturity meter probes and monitor concrete temperatures according to AASHTO T 325. Monitor
the temperature differential from the center of the concrete mass to the surface. Provide internal cooling,
external heating, or insulation to ensure the temperature differential does not exceed 35 °F (20 ºC) during
placing, curing, and immediately after curing ends.
Using the strength-maturity relationship developed for the approved concrete mixture determine in-place
concrete compressive strength of the overlay. Measure concrete temperature and calculate in-place
maturity.
(a) Cold weather. See Subsection 568.13(a).
532
Section 569
(b) Hot weather. See Subsection 568.13(b).
(c) Evaporation. See Subsection 568.13(c).
(d) Rain. See Subsection 552.10(d).
569.15 Handling and Placing Concrete. See Subsection 552.11.
(a) General. See Subsection 552.11(a).
(b) Placing methods. See Subsection 552.11(c) and the following:
(1) Class HPC(O). Do not broom mortar from the concrete from the front edge of the placement.
(2) Class LMC. Immediately ahead of placing overlay mixture, broom a thin coat of the
concrete overlay mixture and scrub it into the surface as a grout-bond coat at the front edge of
the placement. Work evenly over the surface in front of the front edge of the placement.
(c) Consolidation. See Subsection 552.11(d).
Use a self-propelled finishing machine capable of forward and reverse movement under positive
control. Ensure the length of the screed is sufficient to extend at least 6 inches (150 millimeters)
beyond the edge of both ends of the section being placed. Provide finishing machine capable of
consolidating the concrete by vibration and of raising screeds to clear the concrete for traveling in
reverse. Provide either a rotating roller-type or an oscillating screed-type finishing machine.
Use rotating roller-type machines with one or more rollers, augers, and 1,500 to 2,500 vibrations per
minute (25 to 42 hertz) vibratory pans.
Use oscillating screed-type machines with vibrators on the screeds whose frequency of vibration can
be varied between 3,000 and 15,000 vibrations per minute (50 to 250 hertz). Use metal screeds with
a bottom face of not less than 4 inches (100 millimeters) wide.
Use handheld vibrators at the concrete edges and adjacent to expansion joints.
569.16 Construction Joints. See Subsection 552.12 and the following:
Form the vertical edge at construction joints by bulkhead or saw cut. Make construction joints straight and
vertical.
569.17 Expansion and Contraction Joints. See Subsection 552.13.
569.18 Finishing Plastic Concrete. See Subsection 552.14 and the following:
(a) Use a self-propelled rotating cylinder machine, either single or double roller that is capable of
forward or reverse movement under positive control. Equip the machine with an oscillating screed
and other devices required to continuously spread, consolidate, and finish the plastic concrete.
Ensure the screed extends the full width of the deck;
(b) Produce a longitudinal trowelled finish along the gutter line for a 12-inch (300-millimeter) width
from the curb face; and
533
Section 569
(c) Proceed at a constant rate so final finishing is complete before a plastic film forms on the
concrete surface. Install a construction dam or bulkhead in case of major delay. During minor delays
of 1 hour or less, protect the end of the placement from drying with layers of wet burlap.
569.19 Concrete Curing. Prevent plastic shrinkage cracking and crusting of the surface. Use the water
method of curing according to Subsection 552.15(b). Use washed burlap and apply soaker hoses or other
approved methods to keep the coverings saturated at all times.
Install maturity meter probes and monitor concreter temperatures according to AASHTO T 325.
Maintain the concrete temperature of the outer most surfaces above
45 °F (7 °C). Monitor the
temperature differential from the center of the concrete mass to its surface. Using the strength-maturity
relationship developed for the approved concrete mixture, determine the in-place concrete compressive
strength of the concrete.
(a) Class HPC(O). Wet cure the concrete for at least 14 days. Provide internal cooling, external
heating, or insulation to ensure the temperature differential does not exceed 35 °F (20 °C). Cure until
the in-place concrete compressive strength of the overlay concrete reaches at least 80 percent of the
minimum compressive strength shown in Table 569-1.
(b) Class LMC. Wet cure the concrete for at least 48 hours and until the maturity meter reading
exceeds 48 maturity hours. Then air cure the concrete for an additional 48 hours and until the
maturity meter reading exceeds 96 maturity hours.
569.20 Texturing. After curing, visually inspect the overlay for cracking or other damage and inspect
for delamination. Perform bond test. Remove and replace delaminated or unbounded portions of the
overlay or portions damaged by rain for freezing. Clean staining or efflorescence to provide a uniform
color to the concrete overlay surface.
After the Table 569-1 bond strength is obtained, groove surface according to Subsection 552.14(c)(1).
Continuously remove slurry and other residue from the overlay by vacuum pickup or other approved
methods. Properly dispose of slurry and other residue off site.
569.21 Acceptance. See Table 569-2 for sampling, testing, and acceptance requirements and the quality
characteristic category.
Material for concrete repair will be evaluated under Subsection 106.03.
Material for overlay concrete will be evaluated under Subsections
106.02 and 106.03. Submit a
production certification with each shipment of cementitious material.
The overlay concrete mixture’s slump, air content, density, and temperature will be evaluated under
Subsections 106.02 and 106.04.
Overlay concrete compressive strength will be evaluated under Subsection
106.05. The lower
specification limit is the minimum required compressive strength at 28 days (fc’) shown in Table 569-1.
Remove and replace concrete represented by cylinders having a compressive strength less than
90 percent of fc’.
534
Section 569
Maximum chloride permeability will be evaluated under Subsection 106.05. The upper specification
limit is the maximum specified chloride permeability value shown in Table 569-1. A single chloride
permeability test result is the average result from 2 samples cast from the same load and tested.
Concrete drying shrinkage for Class HPC(O) will be evaluated under Subsection 106.04. The upper
specification limit is the maximum shown in Table 569-1. If the concrete mixture contains 1.5 gallons
per cubic yard
(7.5 liters per cubic meter) of an approved shrinkage reducing admixture, drying
shrinkage testing is not required and drying shrinkage will be evaluated under Subsection 106.03.
Bond strength of the overlay will be evaluated under Subsection 106.05. The lower specification limit is
the minimum required bond strength at 14 days shown in Table 569-1.
Construction of concrete overlays for bridge decks will be evaluated under Subsections 106.02 and 106.04.
Measurement
569.22 Measure the Section 569 pay items listed in the bid schedule according to Subsection 109.02.
Payment
569.23 The accepted quantities will be paid at the contract price per unit of measurement for the Section
569 pay items listed in the bid schedule, except the overlay concrete contract price will be adjusted
according to Subsection 106.05. Payment will be full compensation for the work prescribed in this
Section. See Subsection 109.05.
Payment for overlay concrete will be made at a price determined by multiplying the contract price by the
lower of the three pay factors determined for compressive strength, chloride permeability, or bond
strength.
535
Section 569
Table 569-2
Sampling, Testing, and Acceptance Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sampling
Point of
Split
Reporting
Remarks
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Source
Aggregate
Measured and
Quality
Subsections
1 per
Source
Yes,
Minimum
Reports
(703.01 &
tested for
703.01 and
material
of material
when
36 days
must be
703.02)
conformance
703.02
type
requested
before
dated
(106.04 & 105)
production
within
1 year of
intended
use
Mix Design
Concrete
Measured and
All
Subsection
1 per
Source
Yes,
Minimum
composition
tested for
569.04
mix
of material
when
36 days
conformance
design
requested
before
(106.04 & 105)
production
Production Start-up (test panel)
HPC(O)
Measured and
Maximum
AASHTO
1 set
Discharge
Yes,
Upon
tested for
chloride
T 277
per test
stream at
when
completing
conformance
permeability(1)
placement
point of
requested
tests
(106.04)
placement(1)
Compressive
AASHTO
"
"
"
"
strength(2)
T 23 & 22
Drying
ASTM
"
"
"
"
shrinkage(4) (5)
C157
Tensile bond
ASTM
5 cores
In-place
"
"
strength
C1583
per test
after
placement
curing is
complete
536
Section 569
Table 569-2 (continued)
Sampling, Testing, and Acceptance Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sampling
Point of
Split
Reporting
Remarks
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
LMC
Measured and
Maximum(1)
AASHTO
1 set
Discharge
Yes
Upon
tested for
chloride
T 277
per test
stream at
completing
conformance
permeability
placement
point of
tests
(106.04)
placement
Compressive
AASHTO
"
"
"
"
strength(3)
T 23 & 22
Tensile bond
ASTM
5 cores
In-place
"
"
strength(9)
C1583
per test
after
placement
curing is
complete
HPC(O)
"
Density(6)
AASHTO
1 per
Point of
No
Upon
and
T 121
load
discharge
completing
LMC
tests
Air content(6)
AASHTO
No
T 152
or
"
"
"
AASHTO
T 196
Slump(6)(7)
AASHTO
No
"
"
"
T 119
Temperature
Field measured
"
"
No
"
537
Section 569
Table 569-2 (continued)
Sampling, Testing, and Acceptance Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sampling
Point of
Split
Reporting
Remarks
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Aggregate
Measured and
Gradation
AASHTO
1 per
Flowing
Yes
Before
(fine & coarse)
tested for
T 27 & T 11
day
aggregate
batching
conformance
stream
(106.04)
(bin, belt,
discharge
conveyor
belt, or
stockpile)
Fineness
AASHTO
"
"
"
modulus
T 27
Moisture test
AASHTO
"
"
"
T 255
Production
HPC(O)
Measured and
Drying
ASTM
Minimum
Point of
No
Upon
tested for
shrinkage(4) (5)
C157
1 per
discharge
completing
conformance
3000 ft2
tests
(106.04)
(280 m2)
HPC(O)
Statistical
Maximum
II
AASHTO
1 set per
Discharge
Yes
Upon
& LMC
(106.05)
chloride
T 277
30 yd3
stream
completing
permeability(1)
(23 m3),
at point
tests
but not
of
less than
placement
1 per day
Compressive
II
AASHTO
"
"
"
"
strength(8)
T 23 & T 22
Tensile bond
II
ASTM
1 set per
In-place
No
"
strength(9)
C1583
3,000 ft2
after curing
(280 m2)
is complete
of overlay,
but not
less than
1 per day
538
Section 569
Table 569-2 (continued)
Sampling, Testing, and Acceptance Requirements
Material or
Type of
Characteristic
Category
Test Methods
Sampling
Point of
Split
Reporting
Remarks
Product
Acceptance
Specifications
Frequency
Sampling
Sample
Time
(Subsection)
(Subsection)
Production (continued)
HPC(O)
Measured and
Density(6)
AASHTO
1 per
Point of
No
Upon
and
tested for
T 121
load
discharge
completing
LMC
conformance
tests
(106.04)
Air content(6)
AASHTO
"
"
No
"
T 152
or
AASHTO
T 196
Slump(6) (7)
AASHTO
"
"
"
"
T 119
Temperature
ASTM
"
"
"
"
C1064
Aggregate
Measured and
Gradation
AASHTO
1 per
Flowing
Yes,
Before
(fine & coarse)
tested for
T 27 & T 11
day
aggregate
when
batching
conformance
stream
requested
(106.04)
(bin, belt,
discharge
conveyor
belt, or
stockpile)
Fineness
AASHTO
"
"
"
modulus
T 27
Moisture test
AASHTO
"
"
"
T 255
539
Section 569
Table 569-2 (continued)
Sampling, Testing, and Acceptance Requirements
(1) Cast at least three 4- by 8-inch (100- by 200-millimeter) maximum chloride permeability cylinders per set and carefully transport the
cylinders to the job site curing facility. Cure the HPC(O) cylinders for 7 days and the LMC cylinders for 3 days according to AASHTO M 201.
Then cure the HPC(O) cylinders at 100 °F ± 10 °F (38 °C ± 5 °C) in saturated lime water until AASHTO T 277 sample conditioning begins and
air dry the LMC cylinders at 73 °F ± 3 °F (23 °C ± 2 °C) at 40 to 60 percent relative humidity. Test for chloride permeability at 28 days by
measuring the total charge passed, in coulombs, over a specified period of time according to AASHTO T 277. The test result is the average of
the measurements on three cylinders cast from the same load. If pigment is used in the concrete mixture, sample concrete at the batch plant
before and after adding pigment. Test at least three specimens with and without pigment. Determine the average difference between the
pigmented and non-pigmented test results. Adjust production test results by the average difference. Report both initial and adjusted test results.
(2) For HPC(O), cast at least fifteen 4- by 8-inch (100- by 200-millimeter) compressive strength cylinders per set and carefully transport the
cylinders to the job site curing facility. Test three cylinders each at 1, 3, 7, 14 and 28 days. A single compressive strength test result is the
average result from three cylinders cast from the same load.
(3) For LMC, cast at least eighteen 4- by 8-inch (100- by 200-millimeter) compressive strength cylinders per set and carefully transport the
cylinders to the job site curing facility. Test three cylinders each at 1, 2, 4, 7, 14 and 28 days. A single compressive strength test result is the
average result from three cylinders cast from the same load.
(4) Drying shrinkage testing is not required if the concrete mixture contains 1.5 gallons per cubic yard (7.5 liters per cubic meter) of an
approved shrinkage reducing admixture.
(5) If testing is required, use 3- by 3- by 11-inch (75- by 75- by 275-millimeter) prisms for drying shrinkage specimens. Cast at least three
drying shrinkage prisms per set and carefully transport the prisms to the job site curing facility. Moist cure the prisms for the duration of the
specified moist curing period for HPC(O) elements. Measure for shrinkage in microstrains determined according to ASTM C157. The zero
measurement is the initial measurement taken at demolding of the specimens at 23½±½ hours after introduction of mixing water to the concrete
mixture. Determine percent drying shrinkage by measuring at the end of specified moist curing period for the structural elements, 1, 4, 7, 14,
28, and 56 days after the end of the specified field moist curing period. Drying shrinkage 28 days after the termination of moist curing (28 days
drying) cannot exceed 60 percent of the maximum specified value shown in Table 569-1. The set drying shrinkage test result is the average
result from three prisms cast from the same load.
(6) For LMC, measure density, slump, and plastic air content 5 minutes after discharge from the mixer chute. Cover wheelbarrow or other
receptacle used to hold sample with a sheet of plastic to prevent evaporation during the 5 minutes before sampling.
(7) If reinforcing fibers are used at an addition rate greater than 0.3 percent by volume, measure slump at the batch plant before adding fibers.
(8) Cast at least six 4- by 8-inch (100- by 200-millimeter) compressive strength cylinders per set and carefully transport the cylinders to the job
site curing facility. Test three cylinders at 28 days. Remainder of cylinders to be used as designated by the CO.
540
Section 569
Table 569-2 (continued)
Sampling, Testing, and Acceptance Requirements
(9) At random locations determined by the CO, core 2-inch (50-millimeter) diameter specimens through the overlay and ½ inch (13 millimeters)
into the substrate concrete. Cure the specimens in situ for the same length of time as the overlay. Test the specimens in situ by attaching a
loading disk with fast setting, high strength epoxy. Measure the tensile pull off bond strength in pounds per square inch (megapascals)
according to ASTM C1583. The average bond strength is the average of the results from three test specimens adjusted as follows: For tests
where failure occurs in the substrate concrete at a depth of ¼ inch (6 millimeters) or greater for more than 50 percent of the specimen, use 150
pounds per square inch (1 megapascal) for that specimen test result in the calculation of the average of the three test specimens. When two of
the three test results have been adjusted, the average bond strength results shall be the greater of 150 pounds per square inch (1 megapascal) or
the calculated value.
541
542
DIVISION 600
INCIDENTAL CONSTRUCTION
543
Section 601
Section 601. — MINOR CONCRETE STRUCTURES
Description
601.01 This work consists of constructing minor concrete structures.
Material
601.02 Conform to the following Subsections:
Air-entraining admixtures
711.02
Chemical admixtures
711.03
Coarse aggregate for concrete
703.02
Color coating
725.15
Concrete coloring agents
711.05
Curing material
711.01
Fine aggregate for concrete
703.01
Hydraulic cement
701.01
Pozzolans
725.04
Reinforcing fibers
725.17
Reinforcing steel
709.01
Sealants, fillers, and seals
712.01
Water
725.01(a)
Construction Requirements
601.03 Composition (Concrete Mix Design). Conform to Table 601-1. Before batching concrete, submit
the proposed concrete proportions for approval on FHWA Form 1606, Minor Concrete Mix Design Trial
Batch Summary or other approved form. As a minimum, submit the following at least 30 days before
production:
(a) Type and sources of material;
(b) Material certification for material;
(c) Saturated surface dry mass of the fine and coarse aggregate per cubic yard (cubic meter) of
concrete;
(d) Gradation of fine and coarse aggregate;
(e) Mass of mixing water per cubic yard (cubic meter) of concrete;
(f) Mass of cement per cubic yard (cubic meter) of concrete. Fly ash, ground iron blast-furnace slag, or
silica fume (micro-silica) may be substituted for cement according to Table 552-3;
(g) Entrained air content of plastic concrete in percent by volume;
(h) Maximum slump of plastic concrete in inches (millimeters); and
544

 

 

 

 

 

 

 

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