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Revised June 2015
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nondestructive testing device commonly used to detect and locate embedded reinforcing steel; the device emits an electromagnetic field and detects disturbances in the field caused by embedded metals.
an expandable device inserted into a hole to be grouted that prevents the grout from flowing back around the injection pipe.
as related to mixing of concrete or mortar, an agitation blade or arrangement of blades used for mixing concrete repair materials.
a mixer consisting essentially of a trough within which mixing paddles revolve about the horizontal axis, or a pan within which mixing blades revolve about the vertical axis.
the controlling lineal dimension of individual particles.
one movement over an area; a layer of material placed in one movement over an area.
thin and tightly adhered oxide film on a metal surface that protects a metal against active corrosion; a dense layer of iron oxides and hydroxides with some mineral content, that is initially formed as bare steel is exposed to oxygen and water, but then protects the steel from further corrosion because it too dense to allow the water and oxygen to reach the steel and continue the oxidation process.
the process by which steel in concrete is protected from corrosion by the formation of a passive layer due to the highly alkaline environment created by the pore water.
state of the metal surface characterized by low corrosion rates in a potential region that is strongly oxidizing for the metal.
screened gravel, most of the particles of which pass a 3/8 in. sieve (9.5 mm) and are retained on a No. 4 sieve (4.75 mm).
a process in which thin flakes of mortar are broken away from a concrete surface, such as by deterioration or by adherence of surface mortar to forms as forms are removed.
a device for obtaining a measure of the resistance of concrete to penetration; customarily determined by the distance that a steel pin is driven into the concrete from a special gun by a precisely measured explosive charge.
material that has the ability to penetrate and seal the surface to which it is applied. (See also sealing compound.)
a drilling process in which a hole is advanced by using a series of impacts to the drill steel and attached bit; the bit is normally rotated during drilling. (See also rotary drilling.)
monitoring of the performance of a structure, typically through nondestructive methods and/or instrumentation with the objective of identifying or monitoring progressing distress or deterioration.
the mass rate of water vapor flow through one square foot of a material or construction of one grain per hour induced by a vapor pressure gradient between two surfaces of one inch of mercury or in units that equal that flow rate.
the property of porous material that permits a fluid (or gas) to pass through it; in construction, commonly refers to water vapor permeability of a sheet material or assembly and is defined as water vapor permeance per unit thickness. (See also water vapor transmission, perm, and permeance.)
permeability to water, coefficient of
the rate of discharge of water under laminar flow conditions through a unit cross-sectional area of a porous medium under a unit hydraulic gradient and standard temperature conditions, usually 68 °F (20 °C).
the ratio of the rate of water vapor transmission through a material or assembly between its two parallel surfaces to the vapor pressure differential between the surfaces. (See also water vapor transmission, permeability, and perm.)
methods of examining nonmetallic matter under suitable microscopes to determine structural relationships and to identify the phases or minerals present; with opaque materials, the color, hardness, reflectivity, shape, and etching behavior in polished sections serve as means of
a measure of the acidity or alkalinity of a solution, with neutrality represented by a value of 7, with increasing acidity represented by increasingly smaller values and with increasing alkalinity represented by increasingly larger values.
an insoluble fine powder mixed with water, oil, or other base that creates color.
a coating defect characterized by minute holes through a coating that expose an underlying coat or the substrate.
a surface cavity with depth equal to or greater than the minimum dimension at the opening.
development of relatively small surface cavities, such as popouts in concrete or certain forms of corrosion of steel; the localized corrosion of a metal surface that is confined to a small area and takes the form of cavities called pits.
the deposition, distribution, and consolidation of a freshly mixed concrete repair material in the place where it is to harden.
the plane along which a composite repair system tends to fracture.
1) a material that increases the plasticity of a fresh cementitious repair material; 2) a substance added to an adhesive to increase softness, flexibility, and extensibility; 3) a substance added to polymer or copolymer to reduce its minimum film forming temperature or its glass transition temperature.
equipment that uses compressed air to deliver shotcrete.
pneumatically applied mortar
1) abrasion of wearing course aggregates caused by traffic loads and the environment; 2) the use of abrasives to smooth a surface.
a thermoplastic high-molecular-weight organic compound used in formulating protective coatings or, in sheet form, as a protective cover for cementitious materials during the curing period.
a high-molecular-weight organic compound, natural or synthetic, containing repeating units.
a mortar or concrete whose properties benefit from the addition of polymer when cured per ASTM C1439, commonly known as polymer-modified materials.
the use of heat, radiation, or reaction with chemical additives to change in the properties of a polymeric system into a final, more stable, usable condition.
a liquid, with or without fillers or reinforcement, that is applied to a substrate and cured by heat or catalysts to form a thermo-set polymer that bonds to and protects the substrate and provides a barrier for containment of chemicals.
any combination of liquid-polymer products used as sealers, coatings, or mortars for application to concrete for repair, protection, or enhancement.
polymer mortar, conductive
see conductive-polymer mortar.
the chemical reaction in which two or more molecules of the same substance combine to form a compound containing the same elements and in the same proportions but of higher molecular weight.
highly chemically inert, long-chain synthetic polymer; fibrillated and monofilament fibers for concrete reinforcement. (See also fibers, polypropylene.)
a polymer prepared by the polymerization of styrene as the sole monomer.
synthetic polymers obtained by the reaction of sodium polysulfide with organic dichlorides.
reaction product of an isocyanate with any of a wide variety of other components containing an active hydrogen group; used to formulate tough, abrasion-resistant coatings and matrices.
colorless, permanently thermoplastic resin; usually supplied as an emulsion or water-dispersible powder characterized by flexibility, stability towards light, transparency to ultraviolet rays, high dielectric strength, toughness, and hardness.
the breaking away of small portions of a concrete surface due to localized internal pressure which leaves a shallow, typically conical, depression; small popouts leave holes up to 10 mm in diameter, medium popouts leave holes 10 to 50 mm in diameter, large popouts leave holes greater than 50 mm in diameter.
an inherent or induced cavity within a particle or within an object; a discontinuity, essentially circular in cross section, in a coating extending through to the underlying coating or the basis material.
the ratio, usually expressed as a percentage, of the volume of voids in a material to the total volume of the material including the voids.
device used to connect an injection hose to a crack or void; may be attached to the concrete surface along a crack or inserted in holes drilled into the concrete.
positive displacement pump
equipment that operates by using a piston or auger to displace a fluid material from a fixed volume chamber. Since positive displacement pumps are capable of pumping high viscosity fluids containing suspended solids at high pressures, they are frequently used in pumping concrete, mortar, or wet-mix shotcrete.
positive side waterproofing
applying waterproofing material to the side of a structural element subjected to hydrostatic pressure.
method of prestressing in which internal or external prestressing tendons are tensioned after concrete has hardened.
post-tensioned construction in which the annular spaces around the tendons are grouted after stressing, thereby bonding the tendon to the concrete section.
post-tensioned construction in which tensile forces are maintained through anchorages at each end of the exposed tendons.
post-tensioned construction where tendons are permanently prevented from bonding to the concrete after stressing.
water that is safe for drinking.
an instrument for automatically maintaining an electrode in an electrolyte at a constant potential or controlled potentials with respect to a suitable reference electrode.
time interval after preparation during which a liquid or plastic mixture is to be used.
pourbaix diagram (electrode potential-pH diagram)
a graphical representation showing regions of thermodynamic stability of species in metal-water electrolyte systems.
equipment for cutting concrete with intense heat generated by the reaction between oxygen and powdered metals.
power trowel (also known as a “power float,” “helicopter,” “trowel machine,” or “whirlybird”)
a piece of light construction equipment used to apply a smooth finish to concrete slabs; power trowels differ in the way they are controlled; ride-on power trowels are controlled by an operator seated on the machinery; walk-behind power trowels are controlled by an operator walking behind the machine.
a siliceous or siliceous and aluminous material, which in itself possesses little or no cementitious value but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties.
the spreading rate of a coating calculated at the recommended dry film thickness and assuming 15% material loss.
any preliminary exposure of a material to the influence of specified atmospheric conditions for the purpose of favorably approaching equilibrium with a prescribed atmosphere.
adding water to aggregate that will be used in dry-mix shotcrete to bring the moisture content of the aggregate to a specified amount, usually 3 to 6%.
dry ingredients of grout, mortar, and concrete mixtures in packages, requiring only the addition of water to produce grout, mortar, or concrete.
1) the process of maintaining a structure in its present condition and arresting further deterioration; 2) application of measures necessary to sustain the existing form, appearance, integrity, and materials of an historic property. (See also maintenance and protection).
a procedure in which hydraulic splitters, water pressure pulses, or expansive chemicals are used in bore holes drilled at points along a predetermined line to induce a crack plane for the removal of concrete.
a method of prestressing reinforced concrete in which the tendons are tensioned before the concrete is placed.
to place a hardened-concrete member or an assembly of units in a state of compression before application of service loads; the stress developed by prestressing, such as by pretensioning or post-tensioning. (See also concrete, prestressed; pretensioning; post-tensioning; and steel, prestressing.)
adding a portion of the mixing water to dry-mix shotcrete materials in the delivery hose at some distance from the nozzle.
the first coat of a material applied following surface preparation; serves to improve the bond of subsequent coats and may have corrosion inhibitive properties for use on metals.
that part of one manufacturer’s production made from the same nominal raw material under essentially the same conditions and designed to meet the same specifications.
measuring equipment used to determine a surface’s profile in order to quantify its roughness.
substance that activates catalysts and promotes polymerization.
selection of proportions of ingredients to make the most economical use of available materials to produce cementitious repair materials with the required properties. (See also mixture.)
made and marketed by one having the exclusive right to manufacture and distribute.
the process of maintaining a concrete structure in its present or restored condition by minimizing the potential for deterioration or damage in the future. (See also maintenance and preservation.)
a test that measures the force required to extract an embedded insert from a concrete mass; the measured ultimate pullout load is used to estimate the in-place compressive strength of the concrete.
a nondestructive testing method based on stress wave propagation; the presence and position of a reflector, such as a crack or void, are indicated by the echo amplitude and time.
the velocity at which compressional or other waves are propagated through a medium.
process by which a molten or curable resin and continuous fibers are pulled through a die of a desired structural shape of constant cross section, usually to form a rod or tendon.
a measure of the properties of a particular grout mix to be pumped as controlled by the equipment being used, the formation being injected, and the engineering objective limitations.
a field procedure used to determine in situ permeability or the ability of a formation to accept grout.
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