absorption The process by which a liquid is drawn into and tends to fill permeable pores in a porous solid body, also, the increase in mass of a porous solid body resulting from penetration of a liquid into its permeable pores.

American Association of State Highway and Transportation Officials (AASHTO) American Association of State Highway and Transportation Officials

American Society of Civil Engineers (ASCE) American Society of Civil Engineers

ASTM International (ASTM) ASTM International

atmosphere for testing RECPs Atmosphere for testing rolled erosion control products: Air maintained at a relative humidity of 65±5% and temperature of 21±2 degrees C (70 ±4 degrees F).

bench-scale test methods Designed to establish guidelines, requirements, and procedures for evaluating the effect of RECPs on seed germination and vegetation enhancement, to protect soil (sand) from hydraulically induced shear stress, and to protect soils from simulated rainfall (rain splash) and minimal runoff induced erosion. Bench-scale test methods are not intended to replace full-scale simulation or field testing in acquisition of performance values that are required in the design of erosion control measures utilizing RECPs or any erosion control material.

Best Management Practice (BMP) Best Management Practice

Bonded Fiber Matrix (BFM) A hydraulically-applied matrix containing organic defibrated fibers and cross-linked insoluble hydro-colloidal tackifiers to provide erosion control and facilitate vegetation establishment on steep slopes and designed to be functional for a minimum of 6 months.

defibrated verb (used with object), to break (wood, paper, garbage, etc.) into fibrous components; reduce to fibers

Department of Transportation (DOT) Department of Transportation

Environmental Protection Agency (EPA) EPA: Environmental Protection Agency

Erosion Control Blanket (ECB) A temporary degradable rolled erosion control product composed of processed natural or polymer fibers mechanically, structurally or chemically bound together to form a continuous matrix to provide erosion control and facilitate vegetation establishment.

Erosion Control Net (ECN)

Erosion Control Technology Council (ECTC) Erosion Control Technology Council

extended-term products An RECP designed to provide erosion protection for longer than 12 months and up to 24 months. These products are used in areas where vegetation establishment may take up to two full growing seasons. These products are often used in semi-arid locations.

Federal Highway Administration (FHWA) Federal Highway Administration

Fiber Reinforced Matrix (FRM) A hydraulically-applied matrix containing organic defibrated fibers, cross-linked insoluble hydro-colloidal tackifiers, and reinforcing natural and / or synthetic fibers to provide erosion control and facilitate vegetation establishment on very steep slopes and designed to be functional for a minimum of 12 months.

geosynthetic A product manufactured from polymeric material used with soil, rock, earth, or other geotechnical engineering material as an integral part of a man-made project, structure, or system.

Geosynthetic Institute (GSI) Geosynthetic Institute

geotextile A permeable geosynthetic material comprised solely of textiles.

Highway Engineering Circular #15 (HEC 15) Highway Engineering Circular #15

Hydraulic Erosion Control Products (HECP)

Hydraulic Mulch (HM) A hydraulically-applied material(s) containing defibrated paper, wood and / or natural fibers that may or may not contain tackifiers used to facilitate vegetation establishment on mild slopes and designed to be functional for up to 3 months.

index test A test procedure that may contain a known bias but which may be used to establish an order for a set of specimens with respect to the property of interest.

International Erosion Control Association (IECA) International Erosion Control Association

International Organization for Standardization (ISO) International Organization for Standardization

long term non-degradable An RECP composed of non-degradable materials that furnishes erosion protection and extends the erosion control limits of vegetation for the design life of a project.

long-term products An RECP designed to provide erosion protection for longer than 24 months and up to 36 months.

lot A unit of production, or a group of other units or packages, taken for sampling or statistical examination, having one or more common properties and being readily separable from other similar units.

machine direction The direction in the plane of the fabric parallel to the direction of manufacture.

Mulch Control Netting (MCN) A planar woven natural fiber or extruded geosynthetic mesh used as a temporary degradable rolled erosion control product to anchor loose fiber mulches.

National Pollutant Discharge Elimination System (NPDES) National Pollutant Discharge Elimination System

National Transportation Product Evaluation Program (NTPEP) National Transportation Product Evaluation Program

natural A class name of various general fibers, of animal, mineral or vegetable origin.

Open WeaveTextile (OWT) A temporary degradable rolled erosion control product composed of processed natural or polymer yarns woven into a matrix, used to provide erosion control and facilitate vegetation establishment.

performance test A test that simulates as closely as practicable selected conditions experienced in the field and which can be used in design.

permanent rolled erosion control products For applications where natural vegetation alone will not sustain expected flow conditions and/or provide sufficient long-term erosion protection, furnish a permanent rolled erosion control product with the necessary performance properties to effectively control erosion and reinforce vegetation under the expected long-term site conditions.

polyolefin A family of polymeric materials that includes polypropylene and polyethylene.

porosity The ratio of the volume of air or void contained within the boundaries of a material to the total volume expressed as a percentage.

Product Approval List (PAL) Product Approval List

Rolled Erosion Control Product (RECP) or (RECPs) A temporary degradable or long-term non degradable material manufactured or fabricated into rolls designed to reduce soil erosion and assist in the growth, establishment and protection of vegetation.

sample A portion of material, which is taken for testing or for recorded purposes and used in the laboratory as a source of individual specimens.

Sediment Retention Fiber Roll (SRFR) A Sediment Retention Fiber Roll is a manufactured 3-dimensional device of a specified filler material encapsulated within a flexible containment material utilized in sediment and flow control applications.

short-term products An RECP designed to provide erosion protection for longer than three months and up to 12 months. This is basically one growing season for the establishment of vegetation.

specific gravity The ratio of the density of the substance in question to the density of a reference substance at specified conditions of temperature and pressure.

specimen A specific portion of a material or laboratory sample upon which a test is performed or which a measurement is taken for that purpose.

Stabilized Mulch Matrix (SMM) A hydraulically-applied matrix containing defibrated organic fibers with, at a minimum, one of the following additives: soil flocculants, crosslinked hydro-colloidal polymers, tackifiers. Utilized to provide erosion control and facilitate vegetation establishment on moderate slopes and designed to be functional for a minimum of 3 months.

stiffness A resistance to bending.

temporary degradable An RECP composed of biologically, photochemically or otherwise degradable materials that temporarily reduces soil erosion and enhances the establishment of vegetation.

temporary rolled erosion control products For applications where natural vegetation alone will provide sufficient permanent erosion protection, furnish a temporary rolled erosion control product with the necessary longevity and performance properties to effectively control erosion and assist in the establishment of vegetation under the anticipated immediate site conditions.

tensile strength The resistance to deformation developed for a specific material and subsequent modulus and elongation when subjected to tension by an external force.

transverse direction The direction in the plane of the fabric perpendicular to the direction of manufacture. Often referred to as the "cross-machine direction.”

Turf Reinforcement Mat (TRM) A rolled erosion control product composed of non-degradable synthetic fibers, filaments, nets, wire mesh and/or other elements, processed into a permanent, three-dimensional matrix of sufficient thickness. TRMs, which may be supplemented with degradable components, are designed to impart immediate erosion protection, enhance vegetation establishment and provide long-term functionality by permanently reinforcing vegetation during and after maturation. Note: TRMs are typically used in hydraulic applications, such as high flow ditches and channels, steep slopes, stream banks, and shorelines, where erosive forces may exceed the limits of natural, unreinforced vegetation or in areas where limited vegetation establishment is anticipated.

ultra-short term products An RECP designed to last three months or less. They are used in areas where vegetation can be quickly established and will be mowed soon after installation. The netting and bonding materials (e.g. stitching thread) on ultra-short term products degrade quickly to prevent entanglement with mowing equipment.

warp (1) The yarn running the length of the fabric in the machine direction. (2) The sheet of yarns wound together or a beam for the purpose of weaving or knitting. (3) Often referred to as the "machine direction.”

weft (1) The yarn running the length of the fabric perpendicular to the machine direction when manufacturing woven or knitted fabrics. (2) Often referred to as the "cross-machine direction.”

yarn A generic term for continuous strands of textile fibers or filaments used to form a textile fabric.