Concrete Waterproofing Glossary
Talc
a mineral with a greasy or soapy feel, very soft, having the compositionMg 3 Si 4 O 10 (OH) 2 . (See also masonry cement and Mohs scale).
Tamp Process
a process for producing concrete products, such as pipe, that uses directmechanical action to consolidate the concrete by the action of tampersthat rise automatically as the form is rotated and filled with concrete from above. (See also centrifugal proces
Tamper
(1) an implement used to consolidate concrete or mortar in molds or forms;
(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
Tamping
the operation of consolidating freshly placed concrete by repeated blows or penetrations with a tamper. (See also consolidation and rodding.)
Tamping Rod
a straight steel rod of circular cross section and having one or both ends rounded to a hemispherical tip.
Temper
to add water to a cementitious mixture as necessary to initially bring the mixture to the desired workability. (See also retemper.)
Temperature Cracking
cracking due to tensile failure caused by temperature drop in members subjected to external restraints or by temperature differential in members subjected to internal restraints (also called thermal cracking).
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
the time interval during which the temperature of a concrete product rises at a controlled rate to the desired maximum in autoclave or atmospheric- pressure steam curing.
Temperature-time Factor
product of temperature multiplied by time for a specific interval. (See alsomaturity factor.)
Ternary Mixture
concrete containing three cementitious materials.
Terrazzo Concrete
marble-aggregate concrete that is cast-in-place or precast and groundsmooth for decorative surfacing purposes on floors and walls.
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.
Tetracalcium Aluminoferrite
a compound in the calcium aluminoferrite series, having the composition4CaO – Al 2 O 3 – Fe 2 O 3 , abbreviated C 4 AF, that is usually assumed to be the aluminoferrite present when compound calculations are made from the results of chemical analysis of p
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.
Thermal Conductance
(of a gas, liquid, or solid) a measure of the rate at which heat passes perpendicularly through a unit area of material of specified thickness for a temperature difference of one degree.
Thermal Conductivity
the ability of a homogeneous material to conduct heat, measured as the steady state heat flow per unit area through a body of unit thickness with one degree temperature difference between the surfaces.
Thermal Contraction
contraction caused by decrease in temperature.
Thermal Diffusivity
(1) thermal conductivity divided by the product of specific heat and density;
(2) an index of the ease which a material undergoes temperature change.
Thermal Expansion
expansion caused by increase in temperature.
Thermal Movement
change of dimension of concrete or masonry resulting from change of temperatures. (See also thermal contraction and thermal expansion.)
Thermal Resistance
the reciprocal of thermal conductance expressed by the symbol R.
Thermal Shock
the subjection of newly hardened concrete to a rapid change in temperature that may cause surface cracking.
Thixotropy
a property of a material to thin upon isothermal agitation and to thicken upon subsequent rest.
Tie Rod
see form tie and tieback.
Tilt-up
a construction technique for casting concrete elements in a horizontal position at the job site and then tilting them to their final position in a structure.
Tilting Mixer
a revolving-drum mixer that discharges by tilting the drum about a fixedor movable horizontal axis at right angles to the drum axis; the drum axis may be horizontal or inclined while charging and mixing.
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 Setting
(1) the time required for a freshly mixed cement paste, mortar, or concrete to achieve initial setting (see initial setting);
(2) the time required for a freshly mixed cement paste, mortar, or concrete to achieve final set. (See also final setting.)
Time-dependent Deformation
deformation resulting from effects such as autogenous volume change, thermal contraction or expansion, creep, shrinkage, and swelling, each of which is a function of time.
Tobermorite Gel
the binder of concrete cured moist or in atmospheric-pressure steam, alime-rich gel-like solid containing
1. 5 to 1.0 mols of lime per mol of silica.
Tolerance
the permitted deviation from a specified dimension, location, or quantity.
Tongue and Groove
a joint in which a protruding rib on the edge of one side fits into a groovein the edge of the other side, abbreviated T & G. (See also keyway.)
Tooling
the act of compacting and contouring a material in a joint.
Top Form
form required on the upper or outer surface of a sloping slab or thin shell.
Topping
(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 floorand roof systems;
(3) the mixture of marble chips and matrix that, when properly processed, produces a terrazzo
Torque Viscometer
an apparatus used for measuring the consistency of slurries in which the energy required to rotate a device suspended in a rotating cup is proportional to viscosity.
Torsional Stress
the shear stress on a transverse cross section resulting from a twisting action.
Transfer Strength
the concrete strength required before stress is transferred from the stressing mechanism to the concrete.
Transit-mixed Concrete
concrete that is mixed totally or mostly in a truck mixer.
Translucent Concrete
a combination of glass and concrete used together in precast and prestressed panels.
Transverse Crack
a crack that occurs across the longer dimension of the member.
Transverse Joint
a joint normal to the longitudinal dimension of a structural element, assembly of elements, slab, or structure.
Traprock
any of various fine-grained, dense, dark-colored igneous rocks, typicallybasalt or diabase (also called trap).
Tremie
a pipe or tube through which concrete is deposited under water, having atits upper end a hopper for filling and a bail for moving the assemblage.
Tremie Seal
(1) the depth to which the discharge end of the tremie pipe is kept embedded in the fresh concrete that is being placed;
(2) a layer of tremie concrete placed in a cofferdam for the purpose of preventing the intrusion of water when the cofferdam is dewat
Trench Form
the vertical sides and semicircular bottom of a trench excavated through compacted soil to provide the exterior form and base for a cast-in-place concrete pipe.
Trial Batch
a batch of concrete prepared to establish acceptable proportions of the constituents.
Triaxial Compression Test
a test in which a specimen is subjected to a confining hydrostatic pressureand then loaded axially to failure.
Triaxial Test
a test in which a specimen is subjected simultaneously to lateral and axial loads.
Trowel
(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;
(3) a fla
Trowel Finish
the smooth finish of an unformed concrete surface obtained by troweling.
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 Mixer
a concrete mixer suitable for mounting on a truck chassis and capable of mixing concrete in transit. (See also horizontal-shaft mixer, inclined- axis mixer, open-top mixer, and agitator.)
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.)
Two-way System
a system of reinforcement; bars, rods, or wires placed at right angles to each other in a slab and intended to resist stresses due to bending of the slab in two directions.