High Performance Concrete Pavements Project Summary
Chapter 26. NEW HAMPSHIRE HPCP PROJECT
Under the TE-30 program, the University of New Hampshire, in conjunction with the New Hampshire Department of Transportation, developed definitions of and showcase presentations for high-performance concrete in both bridge and pavement applications. A CD-ROM was produced containing the definitions as well as the presentation materials and accompanying speaker notes (Goodspeed 1999). On the pavement applications side, a demonstration computer program allowing the optimization of several concrete pavement variables was also developed.
The objectives of this project include the development of performance classifications for high-performance concrete pavement (HPCP), the dissemination of information on HPCP through several showcase presentations, and the development of computer program that develops optimized pavement designs based on performance and variable constraints.
To aid in the development of high-performance concrete pavement designs, three HPCP classifications were developed. These classifications provide recommended values or ranges for different slab, base, and subgrade properties, and also maximum limits on various pavement performance parameters. The concept is that pavements subjected to higher traffic loadings or designed for longer service lives require stronger, more durable materials and more stringent performance requirements. Table 39 summarizes the recommended performance characteristics for three different HPCP classifications (Goodspeed 1999). It is noted that some of the performance characteristics are not defined, and also that the criteria for several of the design characteristics (e.g., permeability and friction number) are not compatible with the selected performance classification.
|DESIGN CHARACTERISTICS||RECOMMENDED RANGE OR VALUE|
|System Parameters||ESAL applications, millions||50-150||> 150|
|Maximum bearing stress, lbf/in2||2||4||6|
|Limiting IRI rating||1.5||1.75|
|Limiting faulting, in./mi||20||15||10|
|Limiting transverse cracks/mi||30||20|
|Design life, years||20||30||> 40|
|Design reliability, %||75-85||85-95|
|Terminal serviceability index||2.5||3|
|PCC Slab Materials||Modulus of rupture, lbf/in2||500-650||650-700||> 700|
|Elastic modulus, lbf/in2||25-50||50-100||> 100|
|Freeze-thaw (ASTM C666), %||60-80||> 80|
|Scaling (ASTM C672)||x = 4, 5||x = 2, 3||x = 0, 1|
|Abrasion (ASTM C944-90a)||1-2||0.5-1||< 0.5|
|Permeability (ASTM C1202), coulombs||1000||2000||3000|
|Coarse aggregate (AASHTO M80-87), class||D||C||B|
|Fine aggregate (AASHTO M6-93), class||B||A|
|Slab Constructibility||Fast track, hours to 3000 lbf/in2||< 24||< 18||< 12|
|Slab Performance||Mean friction number (ASTM E 274)||40-50||35-40||30-35|
|Initial smoothness (profilograph), in./mi||9||7||6|
|Texture (ASTM E965), in.||0.13||0.13-0.25||0.25-0.30|
|Joint Materials||Rubberized asphalt (ASTM D1190, D3405), %||15-20||20-30||> 30|
|Low-Modulus rubberized asphalt (ASTM D3405), %||30-40||40-50||> 50|
|Non-self-leveling silicone (ASTM D3893), %||30-40||40-50||> 50|
|Self-leveling silicone (ASTM D3893), %||30-40||40-50||> 50|
|Preformed compression seal (ASTM D2628), %||45-65||65-85||> 85|
|Joint Constructibility||Load transfer coefficient, J||3.0-3.2||2.8-3.0||< 2.8|
|Joint Performance||Joint faulting, in.||< 0.13||< 0.10|
|Base Materials||Liquid limit (AASHTO T89)||25-28||28-32||> 32|
|Plastic limit (AASHTO T90)||< 10||< 20|
|Abrasion (ASTM C131)||50 max|
|Drainage coefficient, Cd||0.9-1.1||1.1-1.2||> 1.2|
|Stabilized base k-value, lbf/in2/in.||100-200||200-300||> 300|
|Subgrade k-value, lbf/in2/in.||100||150-200||200-250|
|Subgrade California bearing ratio, %||60-70||70-80||> 80|
|Base Constructibility||In-place recycling, %||< 10||< 20||< 30|
|Speed, ft/day||< 500||< 1500||< 3000|
|Base Performance||Erosion resistance (cement-treated base), %||3-5||5-7||7-8|
|Friction coefficient, f||0.9-1.2||1.2-2.0||> 2.0|
Optimization Computer Program
The High Performance Concrete Pavement Optimization Program is available for use by State highway agencies (Goodspeed 1999). The computer program allows for one or more key design variables to be selected for optimization subject to certain constraints. Generally, slab thickness is the design variable that will be optimized, although other design variables, such as joint spacing or PCC compressive strength, can also be selected for optimization.
When optimizing, acceptable ranges must be entered for each variable being optimized. Furthermore, a cost equation must also be defined for each variable being optimized. The cost equation relates the cost of the variable to the design of the pavement system. Several default cost equations are provided for key variables, but users may also define their own unique cost equations (Goodspeed 1999).
Constraint parameters for various performance indicators must also be defined. These are generally equations that link the different design variables to pavement performance. Again, several default constraint parameters are contained in the program (for example, the 1993 AASHTO design procedure [AASHTO 1993] and the 1998 AASHTO Supplement [AASHTO 1998]), but users may define their own unique performance equations (Goodspeed 1999).
After defining the optimization variables and the constraint parameters, the user runs the optimization program to obtain the cost result and the values associated for each optimization variable. A summary report window is generated that summarizes the selected constraint equations, the optimization variable limits, the parameters, the cost equation results, and the optimized variable results (Goodspeed 1999).
The software program is currently available and free upon request. The software can be requested from either the New Hampshire Technology Transfer (T2) Center or the Florida T2 Center:
University of New Hampshire
Durham, NH 03824
University of Florida
Civil Engineering Department
Transportation Research Center
P.O. Box 116585
512 Wiel Hall
Gainesville, FL 32611-6585
(352) 392-2371, ext 245
Point of Contact
Charles H. Goodspeed
University of New Hampshire
Kingsbury Hall, Room 236
Durham, NH 03824
American Association of State Highway and Transportation Officials (AASHTO). 1993. Guide for Design of Pavement Structures. American Association of State Highway and Transportation Officials, Washington, DC.
---. 1998. Supplement to the Guide for Design of Pavement Structures. American Association of State Highway and Transportation Officials, Washington, DC.
Goodspeed, C. H. 1999. High Performance Concrete for Bridge and Pavement Applications. CD-ROM (with HPCP definitions, presentation files and computer program). Durham, NH.