The National Academies Press

Currently Skimming:

Pages 73-96

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.

From page 73... ... 73 APPENDIX C: INTERACTIVE SELECTION TOOL INFORMATION SHEETS AGGREGATE BASE Description: Compactable aggregate base placed on prepared surface and compacted to 90–5% Typical Locations:  Cable barrier  Support posts and poles  Edge of pavement  Gore/median  Guardrail  Mow edge  Slope/embankment Advantages:  Low-cost treatment applicable for new construction and retrofit locations  Aesthetic value determined by aggregate color and type  Can be used in most climate conditions  Uses standard installation/maintenance equipment  Allows for storm water infiltration Limitations and Common Problems:  May not be applicable in areas with snow removal equipment and snow storage  Displacement by errant vehicles and maintenance equipment  May require spot herbicide treatment and re-compaction Relative Costs Installation Moderate Life Cycle Moderate Maintenance Low Repair Low Effective Longevity Moderate Level of Difficulty Installation Low Repair Low Maintenance Low Retrofit Low Read the entire page →
From page 74... ... 74 ASPHALT COMPOSITE Description: Single-step, seamless, cold-spray-applied asphalt emulsion reinforced with fiberglass strands. Site preparation consists of general grubbing, compaction, and application of pre-emergent herbicide to provide a relatively smooth surface to place the product. Read the entire page →
From page 75... ... 75 ASPHALT CONCRETE PAVEMENT Description: Standard Type B asphalt concrete mixed, spread, and compacted per DOT specifications. Material thickness varies and is site specific. Read the entire page →
From page 76... ... 76 CRUMB RUBBER MODIFIED CONCRETE Description: Crumb rubber modified concrete (CRMCrete) is a concrete-based product using a slurry blend of recycled scrap tire crumb rubber material and homopolymer polypropylene high-performance reinforcing fibers. Read the entire page →
From page 77... ... 77 GEOSYNTHETIC CEMENTITIOUS COMPOSITE MATS Description: GCCM is a flexible cement-impregnated fabric that hardens when hydrated to form a thin, durable concrete layer. This material has different proprietary name such as Concrete Cloth™ and Concrete Canvas®. Read the entire page →
From page 78... ... 78 GLASS CULLET Description: Crushed glass (cullet) particles are generally angular in shape and can contain some flat and elongated particles depending on the degree of processing (i.e., crushing) Read the entire page →
From page 79... ... 79 GRAVEL MULCH Description: Graded, crushed rock placed on geosynthetic fabric (herbicide or non-herbicide treated) Typical Locations:  Support posts and poles  Edge of pavement  Gore/median  Slope/embankment Advantages:  Low-cost treatment for new construction and retrofit  Aesthetic value determined by gravel color and texture  Can be used in most climate conditions  Uses standard installation/maintenance equipment  Allows for storm water infiltration Limitations and Common Problems:  May not be applicable in areas with snow removal equipment and snow storage  Displacement by errant vehicles and maintenance equipment  Requires removal of windblown debris  Subject to voids filling with windblown soil, allowing weed development  Gravel should be placed approximately 1–2 inches thick. Read the entire page →
From page 80... ... 80 IRRIGATED ORNAMENTAL VEGETATION Description: Low-growing species that out-competes undesired vegetation. This may include native and/or nonnative vegetation. Read the entire page →
From page 81... ... 81 MINOR CONCRETE PAVEMENT Description: Standard concrete that includes crumb rubber or polypropylene fibers Typical Locations:  Cable barrier  Support posts and poles  Edge of pavement  Gore/median  Guardrail If using with a strong post guardrail, refer to the STRONG POST GUARDRAIL USE WITH RIGID VMS MATERIALS information sheet for examples of recently tested designs with leave-outs.  Mow edge  Slope/embankment Advantages:  Comparable cost to standard concrete paving  Easily installed with standard tools and equipment  Aesthetic value determined by use of colors and patterns Limitations and Common Problems:  Leave-outs may be required due to VMS material rigidity. Read the entire page →
From page 82... ... 82 MODULAR PAVING UNITS Description: Generally concrete or brick paving units available in a variety of shapes, colors, and structural characteristics Typical Locations:  Support posts and poles  Gore/median  Mow edge  Slope/embankment Advantages:  High aesthetic appeal -- variety of colors and patterns  Good for use in urban/high-visibility locations  Applicable for new construction and retrofit  Can be used in most climate conditions  Most contractors have installation equipment  Allows easy repairs and access to subsurface utilities  Can be specified for pedestrian or vehicle traffic  Used with or without mortar  Can be set on impervious or pervious base Limitations and Common Problems:  * Worker exposure is high for installation  Requires supportive edge  Can be dislodged by heavy vehicle traffic  Can be used under guardrail but not considered a typical location  Subject to damage and displacement from errant vehicles, mowers, and snow removal equipment  Subject to voids filling with windblown soil, allowing weed development  Limited slope applications if not set in mortar  Leave-outs may be required due to VMS material rigidity. Read the entire page →
From page 83... ... 83 NATIVE AND NON-IRRIGATED VEGETATION Description: Low-growing species that out-compete undesired vegetation. This may include native and/or nonnative vegetation. Read the entire page →
From page 84... ... 84 ORGANIC MULCH Description: Consists of surface-applied, mulched recycled materials such as chipped wood and bark usually placed on geosynthetic fabric (herbicide or non-herbicide treated) Typical Locations:  Gore/median  Slope/embankment Advantages:  Can be used in most climate conditions  Uses standard installation/maintenance equipment  Aesthetic value determined by color and texture  Applicable for new construction and retrofit  Allows for storm water infiltration  Provides erosion control  Uses recycled materials Limitations and Common Problems:  Limited longevity -- 2 to 3 years  A 4-inch layer mulch depth should be reapplied every 2 to 3 years  Subject to degradation  May require reapplication  May not be suitable for slopes greater than 1V:3H without tackifier  Not suitable in areas subject to fire hazard  Subject to damage and displacement from errant vehicles, wind, mowers, and snow removal equipment  Subject to voids filling with windblown soil, allowing weed development Relative Costs Installation Low Life Cycle Moderate/High Maintenance Moderate Repair Low Effective Longevity Low Level of Difficulty Installation Low Repair Low Maintenance Low Retrofit Low Read the entire page →
From page 85... ... 85 PATTERNED CONCRETE PAVEMENT Description: Standard concrete mixture using color additive and stamped pattern Typical Locations:  Cable barrier  Support posts and poles  Edge of pavement  Gore/median  Guardrail If using with a strong post guardrail, refer to the STRONG POST GUARDRAIL USE WITH RIGID VMS MATERIALS information sheet for examples of recently tested designs with leave-outs.  Mow edge  Slope/embankment Advantages:  High aesthetic appeal -- variety of colors and patterns  Good for use in urban/high-visibility locations  Can be used in most climate conditions  Applicable for new construction and limited retrofit  Low life cycle cost  Most contractors have equipment to install Limitations and Common Problems:  High installation and repair costs -- may be difficult to match color and pattern for repair  Not recommended for retrofit locations such as existing guardrails  Leave-outs may be required due to VMS material rigidity. Read the entire page →
From page 86... ... 86 RECYCLED ASPHALT MILLINGS Description: Compacted recycled asphalt from asphalt milling operations Typical Locations:  Cable barrier  Edge of pavement  Guardrail  Mow edge Advantages:  Can be used in most climate conditions  Applicable for new construction and retrofit  Low life cycle cost  Most contractors have equipment to install  Uses recycled materials from milling operations  Leave-outs are not required Limitations and Common Problems:  Subject to availability  May become dislodged if not compacted properly  Subject to loss of compaction over time, allowing weed development Relative Costs Installation Low Life Cycle Low Maintenance Low Repair Low Effective Longevity Low Level of Difficulty Installation Low Repair Low Maintenance Low Retrofit Low Read the entire page →
From page 87... ... 87 ROCK BLANKET Description: Rock cobble installed using mortar with or without concrete base Typical Locations:  Support posts and poles  Gore/median  Slope/embankment Advantages:  Aesthetic value determined by color and texture  Good for use in urban/high-visibility locations  Applicable for new construction and limited retrofit  Can be used in most climate conditions  Low life cycle cost  Most contractors have equipment to install Limitations and Common Problems:  High installation and repair costs if set in mortar  Can be difficult in retrofit applications due to size of cobble  Leave-outs may be required due to VMS material rigidity. Refer to AASHTO RDG, MASH, recent research, and/or other guidelines to determine leave-out compliance requirements. Read the entire page →
From page 88... ... 88 ROCK SLOPE PROTECTION Description: Rock cobble placed on geosynthetic fabric (herbicide or non-herbicide treated) Typical Locations:  Gore/median  Slope/embankment Advantages:  Provides erosion control  Can be used in most climate conditions  Low life cycle cost  Most contractors have equipment to install  Aesthetic value determined by color and texture  Applicable for new construction and retrofit Limitations and Common Problems: • Limited application areas • Maximum slope 1V:2H • Subject to voids filling with windblown soil, allowing weed development • May require spot herbicide treatments Relative Costs Installation Low Life Cycle Low Maintenance Low Repair Low Effective Longevity Moderate Level of Difficulty Installation Low Repair Low Maintenance Low Retrofit Low Read the entire page →
From page 89... ... 89 RUBBER WEED MAT Description: Mats consisting of recycled rubber tires adhered together with a resin. Cutouts are often provided for post placement. Read the entire page →
From page 90... ... 90 STAMPED ASPHALT PAVEMENT Description: Economical aesthetic treatment for standard asphalt concrete. An imprint tool is used to create pattern(s) Read the entire page →
From page 91... ... 91 STANDARD CONCRETE PAVEMENT Description: Standard concrete mixture Typical Locations:  Cable barrier  Support posts and poles  Edge of pavement  Gore/median  Guardrail If using with a strong post guardrail, refer to the STRONG POST GUARDRAIL USE WITH RIGID VMS MATERIALS information sheet for examples of recently tested designs with leave-outs.  Mow edge  Slope/embankment Advantages:  Aesthetic value determined by color and texture  Applicable for new construction and limited retrofit  Can be used in most climate conditions  Low life cycle cost  Most contractors have equipment to install Limitations and Common Problems:  High installation and repair costs  Can be difficult in retrofit applications such as existing guardrails due to grading and excavation required for installation  Leave-outs may be required due to VMS material rigidity. Read the entire page →
From page 92... ... 92 WEED CONTROL FIBER MAT Description: Mats consisting of synthetic polyester fibers made from recycled plastic Typical Locations:  Cable barrier  Support posts and poles  Guardrail Advantages:  Can be used in most climate conditions  Applicable for new construction and retrofit  Uses standard installation/maintenance equipment  Allows for storm water infiltration  Fire retardant  Variable width rolls to 6 feet  Not subject to UV degradation  Available in various colors for aesthetic appeal  Applicable for new construction and retrofit Limitations and Common Problems:  Areas at ground penetrations should be sealed with caulk or similar material  Subject to damage from wind, mowers, and snow removal equipment  Displacement by errant vehicles and maintenance equipment Relative Costs Installation Moderate/High Life Cycle Low Maintenance Low Repair Low Effective Longevity High Level of Difficulty Installation Low Repair Low Maintenance Low Retrofit Moderate Read the entire page →
From page 93... ... 93 STRONG POST GUARDRAIL USE WITH RIGID VMS MATERIALS The VMSs identified and presented do not present specific design guidance for highway safety appurtenances, nor are they a substitute for any other highway design practice. The user should refer to the AASHTO RDG, MASH for successfully tested hardware, and any specific state DOT practices for warrants, proper placement, and maintenance of roadside safety appurtenances when applying these VMSs (AASHTO 2011b, 2016) Read the entire page →
From page 94... ... 94 For strong steel post W-beam guardrail posts installed in asphalt or concrete surfacing that is thicker than 200 mm (8 inches) , refer to Figure 2 showing AASHTO RDG Figure 5-5l (b) Read the entire page →
From page 95... ... 95 Figure 3. Round Wood Post in Concrete Mow Strip (Moran et al. Read the entire page →
From page 96... ... 96 For More Information AASHTO. Read the entire page →

From page 73...

... 73 APPENDIX C: INTERACTIVE SELECTION TOOL INFORMATION SHEETS AGGREGATE BASE Description: Compactable aggregate base placed on prepared surface and compacted to 90–5% Typical Locations:  Cable barrier  Support posts and poles  Edge of pavement  Gore/median  Guardrail  Mow edge  Slope/embankment Advantages:  Low-cost treatment applicable for new construction and retrofit locations  Aesthetic value determined by aggregate color and type  Can be used in most climate conditions  Uses standard installation/maintenance equipment  Allows for storm water infiltration Limitations and Common Problems:  May not be applicable in areas with snow removal equipment and snow storage  Displacement by errant vehicles and maintenance equipment  May require spot herbicide treatment and re-compaction Relative Costs Installation Moderate Life Cycle Moderate Maintenance Low Repair Low Effective Longevity Moderate Level of Difficulty Installation Low Repair Low Maintenance Low Retrofit Low