| Term |
Definition |
|
| AASHTO |
American Association of State Highway and Transportation Officials. |
| Abrasion |
Removal of material due to a frictional contact. |
| Abrasion And Scratch Resistance |
Ability of a material to resist the infliction of damage in the form of scratches, grooves and other minor imperfections. |
| ABS |
Acrylonitrile-Butadiene-Styrene; a form of thermoplastic. |
| AC |
Asbestos Cement; a composite material used in pipe construction. |
| Acceptance |
By the owner of the work as being fully complete in accordance with the contract documents. |
| Adapter Ring |
In microtunneling, a fabricated ring, usually made from steel, that serves to mate the microtunneling machine to the first pipe section. This ring is intended to create a waterproof seal between the machine and the spigot of the first joint. |
| Addenda |
Written or graphic instruments issued prior to the execution of the agreement, which modify or interpret the contract documents, drawings and specifications, by addition, deletions, clarifications or corrections. |
| Additive |
A substance added in a small amount, usually to a fluid, for a special purpose such as to reduce friction, corrosion, etc. |
| Admixture |
Ingredients added during mixing; often in construction to aid workability of concrete, mortar or grout. |
| Advance |
The motion of the machine in a direction toward the face wall of the entrance pit. |
| Advance rate |
Speed of advance of a pipe jack or other trenchless installation through the ground, generally expressed as either millimetres per minute or metres per day. |
| Aerial sewer |
An unburied sewer (generally sanitary type), supported on pedestals or bents to provide a suitable grade line. |
| Aerobic |
Presence of unreacted or free oxygen (02). |
| Aggressive |
A property of water which favors the corrosion of its conveying structure, |
| Aggressive Index (AI) |
Corrosion index established by the American Water Works Association (AWWA) Standard C-400; established as a criterion for determining the corrosive tendency of the water relative to asbestos-cement pipe; calculated from the pH, calcium hardness (H), |
| Agreement |
The written agreement between the owner and the contractor covering the work to be performed; the contract documents are attached to and made a part of the agreements. Also designated as the contract. |
| Alkalinity |
The capacity of a water to neutralize acids; a measure of the buffer capacity of a water. The major portion of alkalinity in natural waters is caused by (1) hydroxide, (2) carbonates, and (3) bicarbonates. |
| Alumina |
An oxide of aluminum present in clay. |
| AMP |
Asset Management Plan; a structured approach for utilities to achieve long term defined service standards – or – an external bearing used to isolate the final drive from the thrusting force of the machine. |
| Anaerobic |
Able to live and grow where there is no oxygen. |
| Angle of Repose |
The angle which the sloping face of a bank of loose earth, gravel, or other material, makes with the horizontal. |
| Annular filler |
Material for grouting the annular space between the existing pipeline and the lining system. |
| Annulus |
Free space between the existing pipe and any lining. |
| Anode |
(opposite of cathode) The electrode at which oxidation or corrosion occurs. |
| ANSI |
American National Standards Institute, Inc. |
| Apparent Tensile Strength |
A value of tensile strength used for comparative purpose that is determined by tensile testing pipe rings in accordance with ASTM D 2290. This differs from true tensile strength of the material due to a bending moment induced by the change in contour |
| Apparent Tensile Yield |
The apparent tensile strength calculated for the yield condition. |
| Application for Payments |
The form furnished by the engineer which is to be used by the contractor in requesting progress payments, and an affidavit of the contractor that progress payments theretofore received from the owner on account of the work been applied by the contrac |
| Approval |
Accept as satisfactory. |
| Aqueduct |
Large pipe or conduit to convey water from distant source. |
| Aqueous |
Pertaining to water; an aqueous solution is a water solution. |
| ArcInfo™ |
GIS program for sewer data collection and display. |
| Areaway |
A paved surface, serving as an entry area basement or subsurface portion of a building, which is provided with some form of drainage that may be connected to a sewer line. |
| Arterials |
Designation of a main road system with many connecting minor roads. |
| As-Built |
After a sewer has been constructed it is checked for conformance to plan specifications. The actual measurements (As-Built) are written on the plan near the original plan measurements. The As-Built measurements are often set-off in a box to different |
| ASCE |
American Society of Civil Engineers. |
| Asset |
A valuable resource. |
| ASTM |
American Society of Testing and Materials, technical organization formed for the development of standards on characteristics and performance of materials, products, systems and services, and the promotion of related knowledge. |
| Auger |
A flighted drive tube having hex couplings at each end, to transmit torque to the cutting head and transfer spoil back to the machine. |
| Auger boring |
A technique for forming a bore from a drive pit to a reception pit, by means of a rotating cutting head. Spoil is removed back to the drive shaft by helically wound auger flights rotating in a steel casing. The equipment may have limited steering cap |
| Auger machine |
A machine used to drill earth horizontally by means of a cutting head and auger or other functionally similar device. The machine may be either cradle or track type. |
| Auger MTBM |
A type of microtunnel boring machine, which uses auger flights to remove the spoil through a separate casing placed through the product pipeline. |
| Auger TBM |
Tunnel boring machine in which the excavated soil is removed to the drive shaft by auger flights passing through the product pipeline pushed in behind the TBM. |
| Automated Spoil |
An automated spoil transportation system that conveys |
| Available Water |
Water necessary for the performance of work, which may be taken from the fire hydrant nearest the worksite, given conditions of traffic and terrain which are compatible with the use of the hydrant for performance of work. |
| AWWA |
American Water Works Association. |
