Incremental Costs and Performance Benefits of Various Features of Concrete Pavements
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APPENDIX B. QUESTIONNAIRE SURVEY FORMS
As described previously, two surveys were produced, one targeted at highway agencies (to solicit relative performance data) and one targeted at PCC paving contractors (to solicit relative cost data). This appendix presents the actual questionnaire survey forms used in the conduct of both the relative performance and relative cost surveys.
RELATIVE PERFORMANCE DATA COLLECTION FORM
Purpose
The purpose of this form is to document the effects of various portland cement concrete (PCC) pavement design features on pavement performance. This information will be combined with relative cost information obtained from concrete paving contractors to illustrate the cost-effectiveness of various PCC pavement design features.
This research is being performed for the Innovative Pavement Research Foundation (IPRF) with the support of the Federal Highway Administration (FHWA).
Overview
The underlying concept in this form is that various pavement design features or options are selected by designers to provide a performance benefit. Such a benefit (for example, reduced edge stress, better joint load transfer, or a smoother ride) might be measured in terms of an extension in pavement service life or additional traffic capacity. A standard pavement cross section has been identified, and volunteers are being asked to evaluate the change in life, in terms of the expected increase (or decrease) in 18-kip equivalent single axle loads (ESALs), that the feature provides to the pavement. Your response should be based on experience at your agency. If your agency has no experience with a particular design feature, please indicate this by entering "n/a" in the space provided.
Since each agency uses different design and performance periods, we are asking for your estimate of the performance life of the standard pavement section in ESALs for your State's climate zone. The expected increase (or decrease) in ESALs that the design feature provides should be expressed as a percent increase or decrease from the ESALs that you would expect the standard pavement section to carry.
Information gathered during this process will only be reported in summary form, so individual respondents cannot be identified. Individual responses will be kept confidential.
Instructions
It is estimated that this process will take 4 to 6 hours. At the end of the form, please let us know how long the process took. This information will be used to improve any possible research in this area.
At the beginning of the form, a standard concrete pavement section is described. Changes to each section are also described. After reviewing the standard section and the changes, please estimate the expected ESALs for the standard section and the relative change in performance (in terms of relative increase or decrease in allowable ESALs) attributable to each design feature. If you feel that the feature under evaluation allows the pavement to carry 8 percent more ESALs, it would receive a performance rating of 1.08.
Several States have multiple climate zones as defined in the LTPP research program. The four climate zones identified by LTPP are listed in table 1. For example, a region that has a high potential for moisture throughout the year and low temperatures that are not considered a problem would be classified as a wet-freeze climate zone. If your agency has different design procedures or performance expectations for different climate zones, please complete a form for each zone. Please indicate the climate zone on the form.
Table 1. LTPP Climatic Regions.
| LTPP Climatic Regions |
| Wet Freeze |
| Dry Freeze |
| Wet Non-Freeze |
| Dry Non-Freeze |
Construction Section
For the purposes of this project, assume the following conditions:
- Rural mainline divided highway construction or reconstruction.
- Average daily traffic (ADT) is 20,000 vehicles per day in each direction with 15% trucks. This is approximately 1,000,000 ESALs per year in the design lane. Assume no growth in ESALs during the life of the pavement.
- Project located within 50 miles of mobilization center.
- 5 miles in length.
- 4 lanes of traffic (2 lanes in each direction).
- The project will be constructed at grade with no earthwork and all paving is on longitudinal slopes less than 5%.
- Construction is performed during normal daytime business hours.
- Standard slipform paving equipment used for construction.
- Portable concrete batch plant will be utilized.
- The concrete for this project is a typical local mix.
- Local environmental regulations will govern the project.
- Local specifications for construction apply for highway work.
- Local load restrictions will be used.
DESIGN FEATURE PERFORMANCE FORMS
| Reference/Standard Pavement Section |
Performance |
 |
- Two lanes, 10-in thick PCC, 12 ft wide lanes tied with #5 deformed tie bars spaced 30 in o.c.
- Transverse joints at 15-ft spacing with no skew and 1.25 in diameter by 18 in long epoxy-coated dowel bars at 12 in o.c.
- Joints have a 1/8 in control sawcut at 1/3 the depth of the concrete slab, a 3/8 in widening sawcut at 1.75 in depth, and backer rod is used before placing a hot-poured asphalt sealant with a 1:1 aspect ratio.
- 6-in dense-graded crushed aggregate base layer.
- Prepared subgrade scarified to a depth of 6 in and recompacted at optimum moisture content.
- Concrete mix design calls for type I cement with a target strength of 650 psi flexural and 4,500 psi compressive (28-day, ASTM C78, third-point loading).
- No drainage layer, no underdrains.
- 6-in asphalt shoulders over 10-in dense-graded aggregate base, 10 ft wide on the truck lane and 4 ft wide on the passing lane.
- Initial smoothness requirements are 7 to 9 inches per mile with no incentive or penalty with a 0.20-in blanking band. Grinding is required on all areas outside of tolerance at no additional cost.
Climate zone:________________
SUBGRADE |
Lime Treated Subgrade | Relative Performance_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Add 12-in lime stabilized subgrade.
| |
BASE/SUBBASE |
Directly on Subgrade | Relative Performance_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Pavement constructed directly on prepared subgrade.
| |
Cement Stabilized Relative Performance | Relative Performance_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Add 6-in cement stabilized base.
| |
Asphalt Stabilized Relative Performance | Relative Performance_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Add 6-in asphalt stabilized base.
| |
DRAINAGE |
Open-Graded Aggregate (nonstabilized) Base plus underdrain system Relative Performance | Relative Performance_________________ |
- 6-in open-graded, nonstabilized granular drainage layer.
- 6-in dense-graded, crushed aggregate base layer.
- Open-graded trench edge drains wrapped with geotextile with 6-in flexible pipe and rigid pipe outflows at 500 ft spacing.
| |
Cement-Treated Permeable Base (CTPB) plus underdrain system Relative Performance | Relative Performance_________________ |
- 6-in CTPB layer.
- 6-in dense-graded, crushed aggregate base layer.
- Open-graded trench edge drains wrapped with geotextile with 6-in flexible pipe and rigid pipe outflows at 500 ft spacing.
| |
Asphalt-Treated Permeable Base (ATPB) plus underdrain system Relative Performance | Relative Performance_________________ |
- 6-in ATPB layer.
- 6-in dense-graded, crushed aggregate base layer.
- Open-graded trench edge drains wrapped with geotextile with 6-in flexible pipe and rigid pipe outflows at 500 ft spacing.
|
|
CTPB with daylight drainage into ditch (no underdrain system) Relative Performance | Relative Performance_________________ |
- 6-in CTPB layer.
- 6-in dense-graded, crushed aggregate base layer.
| |
ATPB with daylight drainage into ditch (no underdrain system) Relative Performance | Relative Performance_________________ |
- 6-in ATPB layer.
- 6-in dense-graded, crushed aggregate base layer.
| |
THICKNESS/SLAB SIZE |
12-inch PCC Relative Performance | Relative Performance_________________ |
- 12-in PCC pavement with 18-ft transverse joint spacing.
- Transverse jointing details remain the same.
- Longitudinal jointing remains the same.
| |
8-inch PCC Relative Performance | Relative Performance_________________ |
- 8-in PCC pavement with 12-ft transverse joint spacing.
- Transverse jointing details remain the same.
- Longitudinal jointing remains the same.
| |
SHOULDERS |
16-inch Gravel Relative Performance | Relative Performance_________________ |
- Gravel shoulder on truck lane and passing lane.
| |
Tied PCC Partial-Depth Relative Performance | Relative Performance_________________ |
- 6-in tied PCC, partial-depth, with 10-in dense-graded aggregate base.
- Tied shoulder on truck lane, standard shoulder on passing lane.
- 10 ft wide on the truck lane, 4 ft wide on the passing lane.
| |
Tied PCC Full-Depth Relative Performance | Relative Performance_________________ |
- 10-in tied PCC, full-depth, with 6-in dense-graded aggregate base.
- Tied shoulder on truck lane, standard shoulder on passing lane.
- 10 ft wide on the truck lane, 4 ft wide on the passing lane.
| |
Widened truck lane (24 inches) plus standard asphalt shoulder Relative Performance | Relative Performance_________________ |
- The truck lane is paved 24 in wider, but striped at the conventional width.
| |
PAVEMENT CROSS SECTION |
Trapezoidal Cross Section | Relative Performance_________________ |
- Trapezoidal cross section 8 in thick at the outside edge of the passing lane and 11 in thick on the outside of the truck lane.
| |
Thickened Edge | Relative Performance_________________ |
- Thickened edge from 8 in at the centerline of the 2 lanes to 11 in at the outside edge of the passing lane and truck lane.
| |
JOINTS/LOAD TRANSFER |
10-inch PCC, Epoxy-Coated Dowel Bars, Skewed Joints | Relative Performance_________________ |
- 10-in PCC, 15-ft skewed transverse joint spacing, 1.25-in diameter by 18 in long epoxy-coated dowel bars at 12 in on-center. Joints are skewed counter-clockwise at 2 ft per 12-ft lane.
| |
10-inch PCC, No Dowel Bars | Relative Performance_________________ |
- 10-in PCC, 15-ft perpendicular transverse joint spacing, with aggregate interlock and no dowel bars.
| |
10-inch PCC, Dowel Bars, No Epoxy |
Relative Performance_________________ |
- 10-in PCC, 15-ft perpendicular transverse joint spacing, 1.25-in diameter by 18 in long dowel bars at 12 in on-center. No epoxy coating on the dowel bars.
| |
10-inch PCC, Epoxy-Coated Dowel Bars
(reduced number of dowel bars) | Relative Performance_________________ |
- 10-in PCC, 15-ft perpendicular transverse joint spacing, 1.25-in diameter by 18 in long epoxy-coated dowel bars with 3 bars centered in each wheel path at 12 in on-center.
| |
12-inch PCC, Epoxy-Coated Dowel Bars | Relative Performance_________________ |
- 12-in PCC, 20-ft perpendicular transverse joint spacing, 1.50-in diameter by 18 in long epoxy-coated dowel bars at 12 in on-center.
| |
9.5-inch Continuously Reinforced Concrete (CRC), Epoxy-Coated | Relative Performance_________________ |
- 9.5-in CRC with #6 deformed bars 8 in on-center longitudinally and 36 in on-center transversely. All steel is epoxy coated.
| |
9.5-inch CRC, No Epoxy | Relative Performance_________________ |
- 9.5-in CRC with #6 deformed bars 8 in on-center longitudinally and 36 in on-center transversely. The deformed bars have no epoxy coating.
| |
10-inch Jointed Reinforced Concrete Pavement (JRCP), Epoxy-Coated Dowel Bars | Relative Performance_________________ |
- 10-in JRCP with W12x W5.5-6x12 welded wire fabric mesh placed on chairs at mid-height. 30-ft perpendicular transverse joint spacing, 1.25-in diameter by 18 in long epoxy-coated dowel bars at 12 in on-center.
| |
JOINT SEALING |
Silicone Sealant |
Relative Performance_________________ |
- 15-ft transverse joint spacing with silicone sealant.
- 1/8-in initial control sawcut at h/3.
- 3/8-in widening cut, 1.75 in deep to form joint sealant reservoir.
- Backer rod is used before placing silicone sealant with a 2:1 aspect ratio (w:d).
| |
Preformed Compression Sealant | Relative Performance_________________ |
- 15-ft transverse joint spacing with preformed compression sealant.
- 1/8-in initial control sawcut at h/3.
- 3/8-in widening cut to form joint sealant reservoir.
| |
No Sealant | Relative Performance_________________ |
- 15-ft transverse joint spacing with no sealant material.
- 1/8-in initial control sawcut at h/3 with no widening.
| |
Hot-Pour (no joint widening cut) | Relative Performance_________________ |
- 15-ft transverse joint spacing with hot-pour asphaltic sealant.
- 1/8-in initial control sawcut at h/3 with no widening.
- No backer rod is used before filling joint with hot-pour joint sealant.
| |
Silicone Sealant (no joint widening cut) | Relative Performance_________________ |
- 15-ft transverse joint spacing with silicone sealant.
- 1/8-in initial control sawcut at h/3 with no widening.
- No backer rod is used before filling joint with silicone sealant.
| |
CONCRETE STRENGTH/MATERIALS |
750 psi Flexural Strength | Relative Performance_________________ |
- Additional strength is obtained by using additional Type 1 cement.
| |
High-Early Strength |
Relative Performance_________________ |
- Opening to traffic within 48 hours (a.k.a. Fast-Track).
- 550 psi flexural strength at 48 hours, 650 psi flexural acceptance strength. (High-early strength is obtained by using Type III cement).
| |
Well-Graded Mix | Relative Performance_________________ |
- Changing the mix from a gap-graded mix to a well-graded mix. (If the local concrete mix design uses well-graded aggregate, please note that on the survey.)
| |
INITIAL SMOOTHNESS/RIDE
The following table lists several initial smoothness/ride quality ranges and base layer types. For each initial smoothness/ride quality range, please calculate the expected performance increase (or decrease) for the change in base layers. The standard section has been given a performance of "1.0."
Smoothness Criteria, inches/mi. (0.20 in. blanking band) |
Aggregate Base |
Econocrete/Cement Stabilized Base |
AC Stabilized Base |
Open Graded Stabilized Drainage Layer |
| 7 to 9 |
1.0 |
|
|
|
| 5 to 7 |
|
|
|
|
| 3 to 5 |
|
|
|
|
1 to 3 |
|
|
|
|
| < 1 |
|
|
|
|
Standard Type of Profilograph: ______________________
IMPACT RANKING
General
To complete the analysis portion of this project, please "force rank" the concrete pavement design features in the table below based on their overall importance to pavement performance. Since pavement performance is based on several factors, a ranking is required for each one.
Please rank the pavement design features below from 1 to 10 for each pavement performance measure, with 1 indicating the feature that has the greatest impact and 10 the least. For example, for Cracking, if you believe Subgrade has the greatest impact, you would enter 1 for that feature under Cracking. You would enter 2 for the feature that you believe has the next greatest impact, and so on. There can be no ties, so please do not use the same number twice.
| Pavement Design Feature |
Pavement Performance Measures |
| Cracking |
Spalling |
Faulting |
Smoothness* |
| Subgrade |
|
|
|
| Base/Subbase |
|
|
|
| Drainage |
|
|
|
| Thickness/Slab Size |
|
|
|
| Shoulders |
|
|
|
| Pavement Cross Section |
|
|
|
Joints/Load Transfer |
|
|
|
Joint Sealing |
|
|
|
Concrete Strength/Materials |
|
|
|
Initial Smoothness/Ride |
|
|
|
__________________
*Although smoothness is not a specific perfomance measurement used in most performance models, smoothness is considered a general indicator of the overal pavement perfomance. In addition, smoothness is representative of the traveling public's perception of the quality of highways. As such, please rank smoothness along with the more specific performance measures.
What basis did you use for filling out this form:
__________ Engineering experience/judgment only
__________ Performance modeling
__________ Some performance modeling along with judgment
Please provide a short description of your State's standard concrete pavement maintenance activities:
RELATIVE COST FORMS
Purpose
The purpose of this project is to document the construction costs of different design features for portland cement concrete (PCC) pavements. This information will be combined with performance information obtained from State Highway Agencies to illustrate the relationship between the costs of various concrete pavement design features.
This research is being performed for the Innovative Pavement Research Foundation (IPRF) with the support of the Federal Highway Administration (FHWA).
Overview
The underlying concept in this project is that various pavement design features or options are selected by designers to provide a performance benefit. Such a benefit (for example, reduced edge stress, better joint load transfer, or a smoother ride) might be measured in terms of an extension in pavement service life or additional traffic capacity. A standard pavement cross section has been identified, and you are being asked to provide information on the cost of various design features.
Since construction costs vary from State to State, we are asking for your estimate of the relative change in cost. This should be expressed as a percent increase (or decrease) from the expected construction cost of the standard pavement section.
Information gathered during this process will only be reported in summary form, so individual respondents cannot be identified. Individual responses will be kept confidential.
Instructions
Please review the entire form. It is estimated that this process will take 4 to 6 hours to complete. Please let us know how long the process took. This information will be used to improve any possible future projects.
At the beginning of the form, a standard concrete pavement section is described. Changes to each section are also described. After reviewing the standard section and the changes, please calculate the relative change in construction cost that is appropriate for your company and these concrete pavement design features. The standard section is given a cost of "1.0." So, if you feel that the feature under evaluation increases the construction cost of the pavement by 8 percent, it would receive a relative cost rating of 1.08.
Construction Section
For the purposes of this project, assume the following conditions:
- Rural mainline divided highway construction or reconstruction.
- Project located within 50 miles of mobilization center.
- 5 miles in length.
- 4 lanes of traffic (2 lanes in each direction).
- The project will be constructed at grade with no earthwork and all paving is on longitudinal slopes less than 5%.
- Construction is performed during normal daytime business hours.
- Standard slipform paving equipment used for construction.
- Portable concrete batch plant will be utilized.
- The concrete for this project is a typical local mix.
- Local environmental regulations will govern the project.
- Local specifications for construction apply for highway work.
- Local load restrictions will be used.
RELATIVE COST FORM
| Reference/Standard Pavement Section |
Relative Cost — 1.00 |
|
-
Two lanes, 10-in thick PCC, 12 ft wide lanes tied with #5 deformed tie bars spaced 30 in o.c.
-
Transverse joints at 15-ft spacing with no skew and 1.25 in diameter by 18 in long epoxy-coated dowel bars at 12 in o.c.
-
Joints have a 1/8 in control sawcut at 1/3 the depth of the concrete slab, a 3/8 in widening sawcut by 1.75 in depth, and backer rod is used before placing a hot-poured asphalt sealant with a 1:1 aspect ratio.
-
6-in dense-graded crushed aggregate base layer.
-
Prepared subgrade scarified to a depth of 6 in and recompacted at optimum moisture content.
-
Concrete mix design calls for type I cement with a target strength of 650 psi flexural and 4,500 psi compressive (28-day, ASTM C78, third-point loading).
-
No drainage layer, no underdrains.
-
6-in asphalt shoulders over 10-in dense-graded aggregate base, 10 ft wide on the truck lane and 4 ft wide on the passing lane.
-
Initial smoothness requirements are 7 to 9 inches per mile with no incentive or penalty with a 0.20-in blanking band. Grinding is required on all areas outside of tolerance at no additional cost.
SUBGRADE |
Lime Treated Subgrade |
Relative Cost_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Add 12-in lime stabilized subgrade.
|
|
BASE/SUBBASE |
Directly on Subgrade |
Relative Cost_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Pavement constructed directly on prepared subgrade.
|
|
Cement Stabilized Relative Performance |
Relative Cost_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Add 6-in cement stabilized base.
|
|
Asphalt Stabilized Relative Performance |
Relative Cost_________________ |
- Eliminate 6-in dense-graded aggregate base course.
- Add 6-in asphalt stabilized base.
|
|
DRAINAGE |
Open-Graded Aggregate (nonstabilized) Base plus underdrain system Relative Performance |
Relative Cost_________________ |
- 6-in open-graded, nonstabilized granular drainage layer.
- 6-in dense-graded, crushed aggregate base layer.
- Open-graded trench edge drains wrapped with geotextile with 6-in flexible pipe and rigid pipe outflows at 500 ft spacing.
|
|
Cement-Treated Permeable Base (CTPB) plus underdrain system Relative Performance |
Relative Cost_________________ |
- 6-in CTPB layer.
- 6-in dense-graded, crushed aggregate base layer.
- Open-graded trench edge drains wrapped with geotextile with 6-in flexible pipe and rigid pipe outflows at 500 ft spacing.
|
|
Asphalt-Treated Permeable Base (ATPB) plus underdrain system Relative Performance |
Relative Cost_________________ |
- 6-in ATPB layer.
- 6-in dense-graded, crushed aggregate base layer.
- Open-graded trench edge drains wrapped with geotextile with 6-in flexible pipe and rigid pipe outflows at 500 ft spacing.
|
|
CTPB with daylight drainage into ditch (no underdrain system) Relative Performance |
Relative Cost_________________ |
- 6-in CTPB layer.
- 6-in dense-graded, crushed aggregate base layer.
|
|
ATPB with daylight drainage into ditch (no underdrain system) Relative Performance |
Relative Cost_________________ |
- 6-in ATPB layer.
- 6-in dense-graded, crushed aggregate base layer.
|
|
THICKNESS/SLAB SIZE |
12-inch PCC Relative Performance |
Relative Cost_________________ |
- 12-in PCC pavement with 18-ft transverse joint spacing.
- Transverse jointing details remain the same.
- Longitudinal jointing remains the same.
|
|
8-inch PCC Relative Performance |
Relative Cost_________________ |
- 8-in PCC pavement with 12-ft transverse joint spacing.
- Transverse jointing details remain the same.
- Longitudinal jointing remains the same.
|
|
SHOULDERS |
16-inch Gravel Relative Performance |
Relative Cost_________________ |
- Gravel shoulder on truck lane and passing lane.
|
|
Tied PCC Partial-Depth Relative Performance |
Relative Cost_________________ |
- 6-in tied PCC, partial-depth, with 10-in dense-graded aggregate base.
- Tied shoulder on truck lane, standard shoulder on passing lane.
- 10 ft wide on the truck lane, 4 ft wide on the passing lane.
|
|
Tied PCC Full-Depth Relative Performance |
Relative Cost_________________ |
- 10-in tied PCC, full-depth, with 6-in dense-graded aggregate base.
- Tied shoulder on truck lane, standard shoulder on passing lane.
- 10 ft wide on the truck lane, 4 ft wide on the passing lane.
|
|
Widened truck lane (24 inches) plus standard asphalt shoulder Relative Performance |
Relative Cost_________________ |
- The truck lane is paved 24 in wider, but striped at the conventional width.
|
|
PAVEMENT CROSS SECTION |
Trapezoidal Cross Section |
Relative Cost_________________ |
- Trapezoidal cross section 8 in thick at the outside edge of the passing lane and 11 in thick on the outside of the truck lane.
|
|
Thickened Edge |
Relative Cost_________________ |
- Thickened edge from 8 in at the centerline of the 2 lanes to 11 in at the outside edge of the passing lane and truck lane.
|
|
JOINTS/LOAD TRANSFER |
10-inch PCC, Epoxy-Coated Dowel Bars, Skewed Joints |
Relative Cost_________________ |
- 10-in PCC, 15-ft skewed transverse joint spacing, 1.25-in diameter by 18 in long epoxy-coated dowel bars at 12 in on-center. Joints are skewed counter-clockwise at 2 ft per 12-ft lane.
|
|
10-inch PCC, No Dowel Bars |
Relative Cost_________________ |
- 10-in PCC, 15-ft perpendicular transverse joint spacing, with aggregate interlock and no dowel bars.
|
|
10-inch PCC, Dowel Bars, No Epoxy |
|
- 10-in PCC, 15-ft perpendicular transverse joint spacing, 1.25-in diameter by 18 in long dowel bars at 12 in on-center. No epoxy coating on the dowel bars.
|
|
10-inch PCC, Epoxy-Coated Dowel Bars
(reduced number of dowel bars) |
Relative Cost_________________ |
- 10-in PCC, 15-ft perpendicular transverse joint spacing, 1.25-in diameter by 18 in long epoxy-coated dowel bars with 3 bars centered in each wheel path at 12 in on-center.
|
|
12-inch PCC, Epoxy-Coated Dowel Bars |
Relative Cost_________________ |
- 12-in PCC, 20-ft perpendicular transverse joint spacing, 1.50-in diameter by 18 in long epoxy-coated dowel bars at 12 in on-center.
|
|
9.5-inch Continuously Reinforced Concrete (CRC), Epoxy-Coated |
Relative Cost_________________ |
- 9.5-in CRC with #6 deformed bars 8 in on-center longitudinally and 36 in on-center transversely. All steel is epoxy coated.
|
|
9.5-inch CRC, No Epoxy |
Relative Cost_________________ |
- 9.5-in CRC with #6 deformed bars 8 in on-center longitudinally and 36 in on-center transversely. The deformed bars have no epoxy coating.
|
|
10-inch Jointed Reinforced Concrete Pavement (JRCP), Epoxy-Coated Dowel Bars |
Relative Cost_________________ |
- 10-in JRCP with W12x W5.5-6x12 welded wire fabric mesh placed on chairs at mid-height. 30-ft perpendicular transverse joint spacing, 1.25-in diameter by 18 in long epoxy-coated dowel bars at 12 in on-center.
|
|
JOINT SEALING |
Silicone Sealant |
Relative Cost_________________ |
- 15-ft transverse joint spacing with silicone sealant.
- 1/8-in initial control sawcut at h/3.
- 3/8-in widening cut, 1.75 in deep to form joint sealant reservoir.
- Backer rod is used before placing silicone sealant with a 2:1 aspect ratio (w:d).
|
|
Preformed Compression Sealant |
Relative Cost_________________ |
- 15-ft transverse joint spacing with preformed compression sealant.
- 1/8-in initial control sawcut at h/3.
- 3/8-in widening cut to form joint sealant reservoir.
|
|
No Sealant |
Relative Cost_________________ |
- 15-ft transverse joint spacing with no sealant material.
- 1/8-in initial control sawcut at h/3 with no widening.
|
|
Hot-Pour (no joint widening cut) |
Relative Cost_________________ |
- 15-ft transverse joint spacing with hot-pour asphaltic sealant.
- 1/8-in initial control sawcut at h/3 with no widening.
- No backer rod is used before filling joint with hot-pour joint sealant.
|
|
Silicone Sealant (no joint widening cut) |
Relative Cost_________________ |
- 15-ft transverse joint spacing with silicone sealant.
- 1/8-in initial control sawcut at h/3 with no widening.
- No backer rod is used before filling joint with silicone sealant.
|
|
CONCRETE STRENGTH/MATERIALS |
750 psi Flexural Strength |
Relative Cost_________________ |
- Additional strength is obtained by using additional Type 1 cement.
|
|
High-Early Strength |
Relative Cost_________________ |
- Opening to traffic within 48 hours (a.k.a. Fast-Track).
- 550 psi flexural strength at 48 hours, 650 psi flexural acceptance strength. (High-early strength is obtained by using Type III cement).
|
|
Well-Graded Mix |
Relative Cost_________________ |
- Changing the mix from a gap-graded mix to a well-graded mix. (If the local concrete mix design uses well-graded aggregate, please note that on the survey.)
|
|
INITIAL SMOOTHNESS/RIDE
The following table lists several initial smoothness/ride quality ranges and base layer types. For each initial smoothness/ride quality range, please calculate the expected cost increase (or decrease) for the change in base layers. The standard section has been given a performance of "1.0."
| Smoothness Criteria, inches/mi. (0.20 in. blanking band) |
Aggregate Base |
Econocrete/Cement Stabilized Base |
AC Stabilized Base |
Open Graded Stabilized Drainage Layer |
| 7 to 9 |
1.0 |
|
|
|
| 5 to 7 |
|
|
|
|
| 3 to 5 |
|
|
|
|
| 1 to 3 |
|
|
|
|
| < 1 |
|
|
|
|
