Glossary
| Absolute viscosity |
| A measure of the viscosity of asphalt with respect to time, measured in poises, conducted at 60°C (140°F). |
| http://www.hawaiiasphalt.com/HAPI/modules/05_materials/05_asphalt.htm#viscosity_grading |
| Acceptance |
| Sampling, testing, and the assessment of test results to determine whether or not the quality of produced material or construction is acceptable in terms of the specifications. |
| http://www.hawaiiasphalt.com/HAPI/modules/09_construction/09_qa.htm#acceptance |
| Aggregate |
| A collective term for the mineral materials such as sand, gravel and crushed stone that are used with a binding medium (such as water, bitumen, portland cement, lime, etc.) to form compound materials (such as asphalt concrete, portland cement concrete, etc.). |
| http://www.hawaiiasphalt.com/HAPI/modules/05_materials/05_aggregate.htm |
| Alligator cracks |
| A series of interconnected cracks caused by fatigue failure of the HMA surface (or stabilized base) under repeated traffic loading. |
| http://www.hawaiiasphalt.com/HAPI/modules/03_general_guidance/03_pavement_distress.htm#alligator_cracking |
| Asphalt |
| the principal asphaltic binding agent in HMA. "Asphalt binder" includes asphalt cement as well as any material added to modify the original asphalt cement properties. |
| http://www.hawaiiasphalt.com/HAPI/modules/05_materials/05_asphalt.htm |
| Asphalt cement |
| A fluxed or unfluxed asphalt specially prepared as to quality and consistency for direct use in the manufacture of bituminous pavements, and having a penetration at 25° C (77° F) of between 5 and 300, under a load of 100 g applied for 5 s. |
| http://www.hawaiiasphalt.com/HAPI/modules/05_materials/05_asphalt.htm |
| Base course |
| The portion of a pavement structure immediately beneath the surface course. Its major function is structural support and usually consists of aggregate and can be either stabilized or unstabilized. |
| http://www.hawaiiasphalt.com/HAPI/modules/08_structural_design/08_pavement_structure.htm#base |
| Batch plant |
| A manufacturing facility for producing HMA. They manufacture HMA in batches rather than continuously. |
| http://www.hawaiiasphalt.com/HAPI/modules/08_structural_design/08_pavement_structure.htm#base |
| Bleeding |
| A film of asphalt binder on the pavement surface caused by the upward migration of asphalt binder in an HMA pavement resulting in the formation of asphalt film on the surface. Same as flushing. |
| http://www.hawaiiasphalt.com/HAPI/modules/03_general_guidance/03_pavement_distress.htm#bleeding |
| Break and seat |
| A process used to prevent joint reflective cracking in an HMA overlay over old PCC pavement. It involves breaking up the underlying rigid pavement into relatively small pieces (on the order of about 0.3 m2 to 0.6 m2 (1 ft2 to 2 ft2) by repeatedly dropping a large weight. The pieces are then seated by 2 to 3 passes of a large rubber tired roller. |
| http://www.hawaiiasphalt.com/HAPI/modules/09_construction/09_surface_preparation.htm#rigid_overlay |
| Breaking |
| The phenomenon when asphalt and water separate in an asphalt emulsion beginning the curing process. |
| http://www.hawaiiasphalt.com/HAPI/modules/09_construction/09_surface_preparation.htm#rigid_overlay |
| CBR |
| California Bearing Ratio. A strength test typically used on unconfined granular material. |
| http://www.hawaiiasphalt.com/HAPI/modules/06_design_factors/06_subgrade.htm#cbr |
| Cessation temperature |
| As HMA cools, the asphalt binder eventually becomes viscous enough to effectively prevent any further reduction in air voids regardless of the applied compactive effort. As a rule-of-thumb the temperature at which this occurs, commonly referred to as cessation temperature, is about 79oC (175°F) for dense-graded HMA. |
| http://www.hawaiiasphalt.com/HAPI/modules/09_construction/09_compaction.htm#time_available |
| CIPR |
| Cold In-Place Recycling. A general term for processes using grinding machines to recycle pavement into base material for new paving. CIPR often uses additives such as emulsions or foamed asphalt for stabilization. |
| http://www.hawaiiasphalt.com/HAPI/modules/04_pavement_types/04_recycled_hma.htm#inplace |
| Compactive effort |
| The combined effect of (1) applying weight to an HMA surface and compressing the material underneath the ground contact area and (2) creating a shear stress between the compressed material underneath the ground contact area and the adjacent uncompressed material. |
| http://www.hawaiiasphalt.com/HAPI/modules/09_construction/09_compaction.htm#equipment |
| Corrugation |
| A pavement surface distortion perpendicular to the traffic direction caused by plastic movement and typified by ripples across a pavement surface. Usually caused by vehicle starting and stopping. |
| http://www.hawaiiasphalt.com/HAPI/modules/03_general_guidance/03_pavement_distress.htm |
| Crude Oil |
| Unrefined petroleum. |
| http://www.hawaiiasphalt.com/HAPI/modules/05_materials/05_asphalt.htm |
| Dense-graded mix |
| Refers to an HMA mix design using an aggregate gradation that is near the FHWA’s 0.45 power curve for maximum density. These are the most common HMA mix designs in the U.S. |
| http://www.hawaiiasphalt.com/HAPI/modules/04_pavement_types/04_mix_types.htm#dense |
| Drum plant |
| A manufacturing facility for producing HMA. They manufacture HMA continuously rather than in batches. |
| http://www.hawaiiasphalt.com/HAPI/modules/09_construction/09_manufacturing.htm#drum |
| Durability |
| A measure of how asphalt binder physical properties change with age (sometimes called age hardening). In general, as an asphalt binder ages, its viscosity increases and it becomes more stiff and brittle. |
| http://www.hawaiiasphalt.com/HAPI/modules/09_construction/09_manufacturing.htm#drum |
| Elastic modulus |
| The relationship between stress and strain within a material’s elastic range. Thus, the "flexibility" of any object depends on its elastic modulus and geometric shape; however, it is important to note that strength (stress needed to break something) is not the same thing as stiffness (as measured by elastic modulus). |
| http://www.hawaiiasphalt.com/HAPI/modules/06_design_factors/06_subgrade.htm#mr |
| Emulsifying agent |
| A substance used in asphalt emulsions to assist the formation of small asphalt cement globules in water by imparting an electrical charge to the surface of the asphalt cement globules so that they do not coalesce. |
| http://www.hawaiiasphalt.com/HAPI/modules/05_materials/05_asphalt.htm#emulsion |
| Emulsion |
| A suspension of small asphalt cement globules in water. The suspension is assisted by an emulsifying agent. |
| http://www.hawaiiasphalt.com/HAPI/modules/05_materials/05_asphalt.htm#emulsion |
| ESAL |
| Equivalent Single Axle Load. Based on the results from the AASHO Road Test, the most common approach to determining traffic loading is to convert wheel loads of various magnitudes and repetitions to an equivalent number of "standard" or "equivalent" loads. The most commonly used equivalent load in the U.S. is the 80 kN (18,000 lbs.) equivalent single axle load. |
| http://www.hawaiiasphalt.com/HAPI/modules/06_design_factors/06_loads.htm#esal |
| Fatigue cracking |
| Cracks caused by fatigue failure of an HMA surface (or stabilized base) under repeated traffic loading. |
| http://www.hawaiiasphalt.com/HAPI/modules/03_general_guidance/03_pavement_distress.htm#alligator_cracking |
| FDR |
| Full-depth CIPR. FDR can be used to depths of 30 mm (12 inches) or more but the most typical applications involve depths of between 150 and 225 mm (6 and 9 inches). |
| http://www.hawaiiasphalt.com/HAPI/modules/04_pavement_types/04_recycled_hma.htm#inplace |
| FHWA |
| Federal Highway Administration. Founded on 3 October 1893 as the Office of Road Inquiry, a small office of the U.S. Department of Agriculture. The Office of Road Inquiry was created to gather and disseminate information on road building. The office grew from just two employees to about 3,500 and its annual budget grew from $10,000 to more than $26 billion. The office is now known as the Federal Highway Administration (FHWA) and is part of the U.S. Department of Transportation, which was formed in 1967. (from FHWA) |
| http://www.fhwa.dot.gov/ctdiv/history.htm |
| Flexible pavement |
| Pavements that are surfaced with bituminous (or asphalt) materials in the surface course. These can be either in the form of pavement surfaces such as a bituminous surface course (BST) generally found on lower volume (or lower traffic) roads, or hot mix asphalt (HMA) surfaces generally used on higher volume roads. These types of pavements are called "flexible" since the total pavement structure "bends" or "deflects" due to traffic loads. |
| http://www.hawaiiasphalt.com/HAPI/modules/04_pavement_types/04_pavement_types.htm |
| Flushing |
| A film of asphalt binder on the pavement surface caused by the upward migration of asphalt binder in an HMA pavement resulting in the formation of asphalt film on the surface. Same as bleeding. |
| http://www.hawaiiasphalt.com/HAPI/modules/03_general_guidance/03_pavement_distress.htm#bleeding |
| Fog seal |
| A light application of a slow-setting asphalt emulsion to the surface of an aged (oxidized) pavement surface. |
| http://www.hawaiiasphalt.com/HAPI/modules/11_maint-rehab/11_maintenance.htm#fog_seal |
| FWD |
| Falling Weight Deflectometer. The FWD is an impact load device used to deliver a transient impulse load to the pavement surface and measure the resultant pavement response (it’s deflection) by a series of sensors. |
| http://www.hawaiiasphalt.com/HAPI/modules/10_pavement_evaluation/10_categories.htm#deflection |