T & G — see tongue and groove.
table, flow — a flat, circular jigging device used in making flow tests for consistency of cement paste, mortar, or concrete. (See also flow [2]).
talc — a mineral with a greasy or soapy feel, very soft, having the composition Mg3Si4O10(OH)2. (See also cement, masonry and Mohs scale).
tamp process — see process, tamp.
(1) an implement used to consolidate concrete or mortar in molds or forms; and
(2) a hand-operated device for consolidating floor topping or other unformed concrete by impact from the dropped device in preparation for strikeoff and finishing; contact surface often consists of a screen or a grid of bars to force coarse aggregates below the surface to prevent interference with floating or troweling. (See also jitterbug.)
tamping — the operation of consolidating freshly placed concrete by repeated blows or penetrations with a tamper. (See also consolidation and rodding).
tamping rod — see rod, tamping.
tangent modulus — see modulus of elasticity.
T-beam — a beam composed of a stem and a flange in the form of a T.
telltale — any device designed to indicate movement of formwork or of a point on the longitudinal surface of a pile under load.
temperature, glass-transition — the midpoint of the temperature range over which an amorphous material (such as glass or a high polymer) changes from (or to) a brittle, vitreous state to (or from) a plastic state.
temperature, heat-deflection — the temperature at which a plastic material has an arbitrary deflection when subjected to an arbitrary load and test condition; this is an indication of the glass-transition temperature.
temperature, minimum film-forming — the minimum temperature at which a synthetic latex or emulsion will coalesce when laid on a substrate as a thin film. History
temperature, steel — see reinforcement, temperature.
temperature cracking — see cracking, temperature.
temperature reinforcement — see reinforcement, temperature.
temperature rise — the increase of temperature caused by either absorption of heat or internal generation of heat, for example, hydration of cement in concrete.
temperature-rise period — see period, temperature-rise.
temperature stress — see stress, temperature.
temper — to add water to a cementitious mixture as necessary to initially bring the mixture to the desired workability. (See also retemper.) History
template — a thin plate or board frame used as a guide in positioning or spacing form parts, reinforcement, or anchors; also a full-size mold, pattern, or frame, shaped to serve as a guide in forming or testing contour or shape.
temporary stress — see stress, temporary.
tendon — an assembly consisting of a tensioned element (such as a wire, bar, rod, strand, or a bundle of these elements) used to impart compressive stress in concrete, along with any associated components used to enclose and anchor the tensioned element. History
tendon, bonded — a prestressing tendon that is bonded to the concrete either directly or through grouting.
tendon, concordant — a tendon with a profile that does not produce secondary moments and support reactions due to the prestressing force. History
tendon, eccentric — a prestressing tendon that follows a trajectory not coincident with the gravity axis of the concrete member.
tendon, unbonded — a tendon that is permanently prevented from bonding to the concrete after stressing.
tendons, concentric — tendons following a line coincident with the gravity axis of the prestressed-concrete member.
tendons, deflected — tendons that have a trajectory that is curved or bent with respect to the gravity axis of the concrete member.
tendons, draped — see tendons, deflected.
tendons, harped — see tendons, deflected.
tendon profile — the path or trajectory of the prestressing tendon.
tensile strength — see strength, tensile.
tensile strength, splitting — tensile strength of concrete determined by a splitting tensile test.
tensile stress — see stress.
tension, diagonal — the principal tensile stress resulting from the combination of normal and shear stresses acting upon a structural element.
tension reinforcement — see reinforcement, tension.
ternary mixture — see mixture, ternary.
terrazzo concrete — see concrete, terrazzo.
tesserae — small pieces of glass or marble tile used in mosaics.
test — a trial, examination, observation, or evaluation used as a means of measuring either a physical or a chemical characteristic of a material, or a physical characteristic of either a structural element or a structure.
test, air-permeability — a procedure for measuring the fineness of powdered materials such as portland cement.
test, ball — a test to determine the consistency of freshly mixed concrete by measuring the depth of penetration of a cylindrical metal weight with a hemispherical bottom. (See also Kelly ball.)
test, Blaine — a method for determining the fineness of cement or other fine material on the basis of the permeability to air of a sample prepared under specified conditions.
test, compression — test made on a test specimen of mortar or concrete to determine the compressive strength; in the United States, unless otherwise specified, compression tests of mortars are made on 2 in. (50 mm) cubes and compression tests of concrete are made on cylinders 6 in. (152 mm) in diameter and 12 in. (305 mm) high.
test, hot-load — a test for determining the resistance to deformation or shear of a refractory material when subjected to a specified compressive load at a specified temperature for a specified time.
test, Los Angeles abrasion — test for abrasion resistance of concrete aggregates.
test, remolding — a test to measure remoldability.
test, slump — the procedure for measuring slump.
testing machine — a device for applying test conditions and accurately measuring results.
tetracalcium aluminoferrite — a compound in the calcium aluminoferrite series, having the composition 4CaO·Al2O3·Fe2O3 , abbreviated C4AF, that is usually assumed to be the aluminoferrite present when compound calculations are made from the results of chemical analysis of portland cement. (See also brownmillerite.)
texture — the pattern or configuration apparent in an exposed surface, as in concrete and mortar, including roughness, streaking, striation, or departure from flatness.
texturing — the process of producing a special texture on either unhardened or hardened concrete.
T-head — in precast framing, a segment of girder crossing the top of an interior column; also the top of a shore formed with a braced horizontal member projecting on two sides forming a T-shaped assembly.
thermal conductance — see conductance, thermal.
thermal conductivity — see conductivity, thermal.
thermal contraction — contraction caused by decrease in temperature.
thermal diffusivity — see diffusivity, thermal.
thermal expansion — expansion caused by increase in temperature.
thermal movement — change of dimension of concrete or masonry resulting from change of temperatures. (See also contraction and expansion.)
thermal resistance — see resistance, thermal.
thermal shock — see shock, thermal.
thermal stress — see stress, temperature.
thermal volume change — see volume change, thermal.
thermocouple — two conductors of different metals joined together at both ends, producing a loop in which an electric current will flow when there is a difference in temperature between the two junctions.
thermoplastic — becoming soft when heated and hard when cooled.
thermosetting — becoming rigid by chemical reaction and not remeltable.
thin-shell precast — precast concrete characterized by thin slabs and web sections.
thixotropy — a reversible, time-dependent decrease in viscosity when a fluid is subjected to increased shear stress or shear rate. (See also rheology.) History
threaded anchorage — see anchorage, threaded.
(1) loop of reinforcing bars encircling the longitudinal steel in columns;
(2) a tensile unit adapted to holding concrete forms secure against the lateral pressure of unhardened concrete; and
(3) a tension member in a strut-and-tie model. History
tie, form — a mechanical connection in tension used to prevent concrete forms from spreading due to the fluid pressure of fresh concrete.
tie bar — see bar, tie.
tie bar, deformed — see bar, tie.
tie rod — see tie, form and tieback.
tieback — a rod fastened to a deadman, a rigid foundation, or either a rock or soil anchor to prevent lateral movement of formwork, sheet pile walls, retaining walls, bulkheads, etc.
tied column — see column, tied.
tiers — see lifts (preferred term).
tilting mixer — see mixer, tilting.
tilt-up — a construction technique for casting concrete elements in a horizontal position at the jobsite and then tilting them to their final position in a structure.
time-dependent deformation — see deformation, time-dependent.
time, final setting — the time required for a freshly mixed cement paste, mortar, or concrete to achieve final set. (See also time, initial setting.)
time, initial setting — the time required for a freshly mixed cement paste, mortar, of concrete to achieve initial set. (See also time, final setting.)
time of haul — in production of ready mixed concrete, the period from first contact between mixing water and cement until completion of discharge of the freshly mixed concrete.
time of set — see time of setting.
(1) the time required for a freshly mixed cement paste, mortar, or concrete to achieve initial set (see set, initial); or
(2) the time required for a freshly mixed cement paste, mortar, or concrete to achieve final set (see set, final).
tobermorite — a mineral found in Northern Ireland and elsewhere, having the approximate formula Ca5(Si6O16(OH)2·4H2O identified approximately with the artificial product tobermorite (G) of Brunauer, a hydrated calcium silicate having CaO:SiO2 ratio in the range 1.39 to 1.75 and forming minute layered crystals that constitute the principal cementing medium in portland-cement concrete; a mineral with 5 mols of lime to 6 mols of silica, usually occurring in plate-like crystals, which is easily synthesized at steam pressures of about 100 psig and higher; the binder in several properly autoclaved products.
tobermorite gel — see gel, tobermorite.
tolerance — the permitted deviation from a specified dimension, location, or quantity. History
tom — see shore (preferred term).
tongue and groove — a joint in which a protruding rib on the edge of one side fits into a groove in the edge of the other side, abbreviated “T & G.” (See also keyway.)
tool, arrissing — a tool similar to a float, but having a form suitable for rounding an edge of freshly placed concrete.
tool, gutter — a tool used to give the desired shape and finish to concrete gutters.
tooling — the act of compacting and contouring a material in a joint.
top form — see form, top.
(1) a layer of concrete or mortar placed to form a floor surface on a concrete base;
(2) a structural, cast-in-place surface for precast floor and roof systems; and
(3) the mixture of marble chips and matrix that, when properly processed, produces a terrazzo surface.
topping, dry — see dry-shake (preferred term).
topping, monolithic — on flatwork: a higher quality, more serviceable topping course placed promptly after the base course has lost all slump and bleed water.
torque viscometer — see viscometer, torque.
torsional stress — see stress, torsional.
toughness — the property of matter that resists fracture by impact or shock.
trajectoryof prestressing force — see path of prestressing force.
transfer — to shift the tensioning force for a strand or strands from a jack or pretensioning bed to a concrete or masonry member. History
transfer bond — see bond, transfer.
transfer length — see length, transfer (preferred term).
transfer strength — see strength, transfer.
transformed section — see section, transformed.
transit-mixed concrete — see concrete, transit-mixed.
transit-mixer — see mixer, truck.
translucent concrete — see concrete, translucent.
transmission length — see length, transfer.
transverse crack — see crack, transverse.
transverse joint — see joint, transverse.
transverse prestress — see prestress, transverse.
transverse reinforcement — see reinforcement, transverse.
transverse strength — see strength, flexural and modulus of rupture.
traprock — any of various fine-grained, dense, dark colored igneous rocks, typically basalt or diabase; also called q-“trap.”
trass — a natural pozzolan of volcanic origin found in Germany, namely, trachytic tuffs that are intensely altered by geologic processes.
traveler — an inverted-U-shaped structure usually mounted on tracks that permit it to move from one location to another to facilitate the construction of an arch, bridge, or building.
travertine — dense to irregularly porous, commonly stratified or banded calcium carbonate, either aragonite or calcite, formed by deposition from hot spring waters.
tremie — a pipe or tube through which concrete is deposited under water, having at its upper end a hopper for filling and a bail for moving the assemblage.
tremie seal — the depth to which the discharge end of the tremie pipe is kept embedded in the fresh concrete that is being placed; a layer of tremie concrete placed in a cofferdam for the purpose of preventing the intrusion of water when the cofferdam is dewatered.
trench form — see form, trench.
trench form (for cast-in-place concrete pipe) — the vertical sides and semicircular bottom of the trench shaped to provide full, firm, and uniform support for the lower 210 degrees of the pipe.
trial batch — see batch, trial.
triaxial compression test — a test in which a specimen is subjected to a confining hydrostatic pressure and then loaded axially to failure.
triaxial test — a test in which a specimen is subjected simultaneously to lateral and axial loads.
tricalcium aluminate — a compound having the composition 3CaO·Al2O3 , abbreviated C3A.
tricalcium silicate — a compound having the composition 3CaO·SiO2, abbreviated C3S, an impure form of which (alite) is a main constituent of portland cement. (See also alite.)
trough, flow — a sloping trough used to convey concrete by gravity flow from either a truck mixer or a receiving hopper to the point of placement. (See also chute.)
trough mixer — see mixer, open-top.
1) a flat, broad-blade steel hand tool used in the final stages of finishing operations to impart a relatively smooth surface to concrete floors and other unformed concrete surfaces;
2) a flat, triangular-blade tool used for applying mortar; or
3) a flat, broad-blade steel hand tool used to place, spread, shape, finish, or otherwise apply materials. (See also fresno trowel. ) History
trowel finish — see finish, trowel.
troweling — smoothing and compacting the unformed surface of fresh concrete by strokes of a trowel.
troweling machine — a motor driven device that operates orbiting steel trowels on radial arms from a vertical shaft.
truck, agitating — a vehicle in which freshly mixed concrete can be conveyed from the site of mixing to the site of placement; while being agitated, the truck body can either be stationary and contain an agitator or it can be a drum rotated continuously so as to agitate the contents; designated “agitating lorry” in the United Kingdom.
truck-mixed concrete — see concrete, transit-mixed.
truck mixer — see mixer, truck.
T-shore — a shore with a T-head.
tub mixer — see mixer, open-top (preferred term).
tube-and-coupler shoring — a load-carrying assembly of tubing or pipe which serves as posts, braces, and ties, a base supporting the posts, and special couplers that connect the uprights and join the various members.
tunnel lining — a structural system of concrete, steel, or other materials to provide support for a tunnel for exterior loads, to reduce water seepage, or to increase flow capacity.
turbidimeter — a device for measuring the particle-size distribution of a finely divided material by taking successive measurements of the turbidity of a suspension in a fluid.
turbidimeter fineness — the fineness of a material such as portland cement, usually expressed as total surface area in square centimeters per gram, as determined with a turbidimeter. (See also Wagner fineness.)
turbine mixer — see mixer, open-top (preferred term).
twin-twisted bar reinforcement — see reinforcement, twin-twisted bar.
two-stage curing — see curing, two-stage.
two-way reinforced footing — a footing having reinforcement in two directions generally perpendicular to each other.
two-way reinforcement — see reinforcement, two-way.
two-way system — see system, two-way.
Type I cement — see cement, normal (preferred term).
Type II cement — see cement, modified (preferred term).
Type III cement — see cement, high-early strength (preferred term).
Type IV cement — see cement, low-heat (preferred term).
Type V cement — see cement, sulfate-resistant (preferred term).
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