Concrete Waterproofing Glossary

Sack Rub

a finish for formed concrete surfaces, designed to produce even texture and fill pits and air holes. (See also surface air voids and rubbed finish.)

either a group of units or portion of material taken, respectively, from a larger collection of units or a larger quantity of material that serves toprovide information that can be used as a basis for action on the largercollection or quantity or on the p

Sampling Plan

(1) a procedure that specifies the number of units of product from a lot that is to be inspected to establish acceptability of the lot;
(2) a prearranged program stipulating locations and procedures for securing samples of a material for testing purposes

Sand

(1) granular material passing the 9.5 mm (3/8 in.) sieve and almost entirely passing the 4.75 mm (No. 4) sieve and predominantly retained on the75 m m (No. 200) sieve, and resulting either from natural disintegrationand abrasion of rock or processing of c

Sand Equivalent

a measure of the relative proportions of detrimental fine dust, clay-like material, or both in soils or fine aggregate.

Sand Pocket

a zone in concrete or mortar containing fine aggregate with little or nocement.

Sand Streak

a streak of exposed fine aggregate in the surface of formed concretecaused by bleeding.

Sand-coarse Aggregate Ratio

ratio of fine to coarse aggregate in a batch of concrete, by mass or byvolume.

Sand-lightweight Concrete

concrete made with a combination of expanded clay, shale, slag, or slate orsintered fly ash and natural sand, with a density generally between 105 and120 lb/ft 3 (1680 and 1920 kg/m 3 ).

Sandblast

a system of cutting or abrading a surface such as concrete by a stream of sand ejected from a nozzle at high speed by compressed air, often used for cleanup of horizontal construction joints or for exposure of aggregate in architectural concrete.

Sandstone

a cemented or otherwise indurated sedimentary rock composed predominantly of sand grains.

Sandwich Panel

a prefabricated panel that is a layered composite formed by attaching two thin facings to a thicker core, for example, a precast-concrete panel consisting of two layers of concrete separated by a nonstructural insulating core.

Saponification

the alkaline hydrolysis of fats forming a soap, more generally the hydrolysis of an ester by an alkali with the formation of an alcohol and a salt of the acid portion.

Saturated Surface-dry

condition of an aggregate particle or other porous solid when the permeable pores are filled with water and no water is on the exposed surfaces.

Saturated Surface-dry Particle Density

the mass of the saturated surface-dry aggregate divided by its displacement volume in water.

Saturation

the condition such that no more liquid can be held or placed within aggregate or hardened concrete.

Saw Cut

a cut in hardened concrete made using abrasive blades or discs.

Sawdust Concrete

concrete in which the aggregate consists mainly of sawdust from wood.

Sawed Joint

a joint cut in hardened concrete, generally not to the full depth of the member, by means of special equipment.

Scaffolding

a temporary structure for the support of deck forms, cartways, or workers, or a combination of these, such as an elevated platform for supporting workers, tools, and materials; adjustable metal scaffolding is frequently adapted for shoring in concrete wor

Scaling

local flaking or peeling away of the near-surface portion of hardenedconcrete or mortar.

Scalping Screen

a sieve for removing oversize particles.

Scarf Connection

a connection made by precasting, beveling, halving, or notching two pieces to fit together; after overlapping, the pieces are secured by bolts or other means.

Scoria

vesicular volcanic ejecta of larger size, usually of basic composition and characterized by dark color; the material is relatively heavy and partly glassy, partly crystalline; the vesicles do not generally interconnect. (See also lightweight aggregate.)

Scour

(1) erosion of soil around concrete members by water;
(2) erosion of a concrete surface, exposing the aggregate.

Scratch Coat

the first coat of plaster or stucco applied to a surface in three-coat work, usually cross-raked or scratched to form a mechanical key with the brown coat.

Screen

production equipment for separating granular material according to size using woven-wire cloth or other similar device with regularly spaced openings of uniform size.

Sealer

a liquid that is applied to the surface of hardened concrete, is colorless, is absorbed by the concrete, leaves little or nothing visible on the surface, and either prevents or decreased the penetration of liquid or gaseous media. (See also coating and cu

Secondary Crusher

a crusher used for the second stage in a process of size reduction of aggregate and the like. (See also primary crusher.)

Segmental Construction

method of construction whereby individual elements are prestressed together by post-tensioning so that the elements act as a monolithic unit in resisting applied loads.

Segregation

(1) nonuniform concentration of components in concrete or mortar;
(2) nonuniform distribution of size fractions in a mass of aggregate;
(3) the gravitational settlement of solids from a liquid (also called separation ).(See also bleeding.)

Self-consolidating Concrete

fresh concrete that can flow around reinforcement and consolidate withinformwork under its own weight without vibration.

Self-desiccation

the consumption of free water by chemical reaction so as to leave insufficient water to cover the solid surfaces and cause a decrease in the relative humidity of the system.

Self-stressing Concrete (mortar Or Grout)

expansive-cement concrete (mortar or grout) in which expansion, if restrained, induces compressive stresses in the concrete (mortar or grout).

Sensor

a device designed to respond to a physical stimulus (as temperature, illumination, and motion) and transmit a resulting signal for interpretation, measurement, or for operating a control.

Service Dead Load

unfactored dead loads.

Service Live Load

unfactored live loads.

Service Load

all loads, static or dynamic, imposed on a structure, or element thereof, during operation of a facility.

Setting

a chemical process that results in a gradual development of rigidity of a cementitious mixture, adhesive, or resin.

Setting Time

(1) time to achieve either initial setting or final setting (see also initial setting and final setting);
(2) the length of time required to set or harden resin or adhesive under heat or pressure.

Settlement

sinking of solid particles in a fresh cementitious mixture after placement and before initial setting. (See also bleeding.)

Settling

the lowering in elevation of sections of pavement or structures due to their mass, the loads imposed on them, or shrinkage or displacement of the support.

Severe Exposure Condition

an environment, normally in cold climate regions, in which concrete may be saturated or in almost continuous contact with moisture before freezing, and where deicing agents are used.

Shale

a laminated and fissile sedimentary rock, the constituent particles of which are principally in clay and silt sizes (the laminations are bedding planes of the rock).

Sharp Sand

coarse sand consisting of particles of angular shape.

Shear

an internal force tangential to the plane on which it acts.

Shear Reinforcement

reinforcement designed to resist shear or diagonal tension stresses. (See also dowel.)

Shear Strength

the maximum shearing stress a flexural member can support at a specific location as controlled by the combined effects of shear forces and bending moment.

Shear Stress

the stress component acting tangentially to a plane.

Shearhead

assembled unit in the top of the columns of flat slab or flat plateconstruction to transmit loads from slab to column.

Shearwall

a wall portion of a structural frame intended to resist lateral forces, such asearthquake, wind, and blast, acting in the plane of the wall.

Sheath

an enclosure in which post-tensioning tendons are encased to prevent bonding during concrete placement. (See also duct.)

Sheathing

(1) material encasing prestressing steel to prevent bonding of the prestressing steel with the surrounding concrete to provide corrosion protection and to contain the corrosion inhibiting coating (also called a sheath);
(2) the material forming the conta

Shielding Concrete

concrete employed as a biological shield to attenuate or absorb nuclear radiation, usually characterized by high density or high hydrogen (water) or boron content, having specific radiation attenuation effects. (See also biological shielding.)

Shooting

placing of shotcrete. (See also gunning.)

Shore

a temporary support for formwork and fresh concrete or for recently built structures that have not developed full design strength (also called prop, tom, post, and strut).

Shoring

(1) props or posts of timber or other material in compression used for the temporary support of excavations, formwork, or unsafe structures;
(2) the process of erecting shores.

Shoring Layout

a drawing prepared before erection showing arrangements of equipment for shoring.

Shorten

to decrease in length. (See also elongation and shrinkage.)

Shotcrete

concrete placed by a high velocity pneumatic projection from a nozzle.

Shoulder

an unintentional offset in a formed concrete surface usually caused by bulging or movement of formwork.

Shrink-mixed Concrete

ready-mixed concrete mixed partially in a stationary mixer and then mixed in a truck mixer.

Shrinkage

decrease in either length or volume of a material resulting from changes in moisture content or chemical changes.

Shrinkage Crack

crack due to restraint of shrinkage.

Shrinkage Cracking

cracking of a structure or member due to failure in tension caused by external or internal restraints as moisture content is reduced, carbonation occurs, or both.

Shrinkage Loss

reduction of stress in prestressing steel resulting from shrinkage of concrete.

Shrinkage Reinforcement

reinforcement designed to resist shrinkage stresses in concrete.

Shrinkage-compensating

a characteristic of grout, mortar, or concrete made using expansivecement in which volume increases after setting and, if properly elastically restrained, induces compressive stresses that are intended to approximately offset the tendency of drying shrink

Shrinkage-compensating Cement

see expansive cement.

Shrinkage-compensating Concrete

concrete containing expansive components usually based on formation of calcium sulfoaluminate (ettringite) in a mixture of calcium aluminate and gypsum. (See also expansive cement.)

SI (SystÃ¨me International)

the modern metric system (refer to ASTM E380).

Side-face Blowout Failure

concrete spalling on the side face around the embedded head with nomajor breakout at the top concrete surface.

Sieve

a metallic plate or sheet, woven-wire cloth, or other similar device with regularly spaced apertures of uniform size mounted in a suitable frame or holder for use in separating granular material according to size.

Sieve Analysis

the process of determining particle-size distribution of an aggregate. (See also grading.)

Sieve Fraction

that portion of a sample that passes through a standard sieve of specified size and is retained by some finer sieve of specified size.

Sieve Number

a number used to designate the size of a sieve. (See also sieve size[preferred term].)

Sieve Size

nominal size of openings between cross wires of a testing sieve.

Significant

values of a test statistic that lie outside of predetermined limits of test precision and so taken to indicate a difference between populations (also called statistically significant).

Silica

silicon dioxide (SiO 2 ).

Silica Flour

very finely divided silica, a siliceous binder component that reacts withlime under autoclave curing conditions, prepared by grinding silica, suchas quartz, to a fine powder (also called silica powder).

Silica Fume

very fine noncrystalline silica produced in electric arc furnaces as a byproduct of the production of elemental silicon or alloys containing silicon.

Silicate

salt of a silicic acid. (See also alite, belite, blast-furnace slag, bredigite, calcium-silicate brick, calcium-silicate hydrate, celite, clay, dicalcium silicate, fire clay, hydraulic hydrated lime, kaolinite, melilite, siliceous- aggregate concrete, sme

Siliceous-aggregate Concrete

concrete made with normal-density aggregates having constituents composed mainly of silica or silicates.

Silicone

a resin characterized by water-repellent properties in which the main polymer chain consists of alternating silicon and oxygen atoms with carbon-containing side groups.

Silt

a granular material resulting from the disintegration of rock with grains largely passing a 75 m m (No. 200) sieve; particles in the range from 2 to50 m m diameter.

Single-sized Aggregate

aggregate in which a major portion of the particles is in a narrow size range.

Skid Resistance

a measure of the frictional characteristics of a surface.

Slab

a molded layer of plain or reinforced concrete, flat, horizontal (or nearly so), usually of uniform but sometimes of variable thickness, and supported by beams, columns, walls, other framework, or on the ground. (See also flat slab and flat plate.)

Slab Bolster

continuous wire bar support used to support bars in the bottom of slabs where the top wire is corrugated at 1 in. (25 mm) centers to hold bars in position. (See also bar support.)

Slab-jacking

the process of either raising concrete pavement slabs or filling voids under them, or both, by injecting a material (cementitious, noncementitious, or asphaltic) under pressure.

Slab-on-ground

a slab cast directly on the ground (also called slab-on-grade).

Slag

see blast-furnace slag.

Slag Cement

granulated blast-furnace slag that has been finely ground and that ishydraulic cement.

Slag-activity Index

the ratio of the compressive strength of a mortar cube made with equal amounts of slag and portland cement to the compressive strength of a mortar cube made with the same portland cement.

Slate

a fine-grained metamorphic rock possessing a well-developed fissility(slaty cleavage), usually not parallel to the bedding planes of the rock.

Sleeve

(1) a pipe or tube passing through formwork for a wall or slab through which pipe, wires, or conduit can be passed after the forms have been stripped;
(2) a device used around an anchor to accommodate adjustment and preloading of the anchor after the con

Slick Line

end section of a pipe line used in placing concrete by pump that is immersed in the placed concrete and moved as the work progresses.

Slip

movement occurring between steel reinforcement and concrete in stressed reinforced concrete, indicating anchorage breakdown.

Slipform

a form that is pulled or raised as concrete is placed

Sloped Footing

a footing having sloping top or side faces.

Sloughing

subsidence of shotcrete, plaster, or the like, generally due to excessive water in the mixture (also called sagging).

Slugging

pulsating and intermittent flow of shotcrete material due to improper useof delivery equipment and materials.

Slump

a measure of consistency of freshly mixed concrete, mortar, or stucco equal to the subsidence measured to the nearest 1/4 in. (5 mm) of the molded specimen immediately after removal of the slump cone.

Slump Cone

a mold in the form of the lateral surface of the frustum of a cone with a base diameter of 8 in. (203 mm), top diameter 4 in. (102 mm), and height12 in. (305 mm), used to fabricate a specimen of freshly mixed concrete for the slump test.

Slump Loss

the amount by which the slump of freshly mixed concrete changes during a period of time after an initial slump test was made on a sample or samples thereof.

Slurry

a mixture of water and any finely divided insoluble material, such asportland cement, slag, or clay in suspension.

Snap Tie

a proprietary concrete wall-form tie, the end of which can be twisted or snapped off after the forms have been removed.

Soffit

the underside of a part or member of a structure, such as a beam, stairway, or arch.

Soil Cement

a mixture of soil and measured amounts of portland cement and water compacted to a high density.

Soil Stabilization

chemical or mechanical treatment designed to either increase or maintain the stability of a mass of soil or otherwise to improve its engineering properties.

Solid Masonry Unit

a unit whose net cross-sectional area in every plane parallel to the bearingsurface is 75 percent or more of its gross cross-sectional area measured in the same plane.

Solid Panel

a solid slab, usually of constant thickness.

Solubility

the amount of one material that will dissolve in another, generally expressed as mass percent, as volume percent, or parts per 100 parts of solvent by mass or volume at a specified temperature.

Solution

a liquid consisting of at least two substances, one of which is a liquid solvent in which the other or others, that may be either solid or liquid, are dissolved.

Soundness

the freedom of a solid from cracks, flaws, fissures, or variations from an accepted standard; in the case of a cement, freedom from excessive volume change after setting; in the case of aggregate, the ability to withstand the aggressive action to which co

Spacer

device that maintains reinforcement in proper position, also a device for keeping wall forms apart at a given distance before and during concreting. (See also spreader.)

Spacing Factor

an index related to the maximum distance of any point in a cement pasteor in the cement paste fraction of mortar or concrete from the periphery of an air void (also called Powers’ spacing factor). (See also Philleo factor.)

Spading

consolidation of mortar or concrete by repeated insertion and withdrawalof a flat, spade-like tool.

Spall

a fragment, usually in the shape of a flake, detached from a larger mass by a blow, the action of weather, pressure, or expansion within the larger mass.

Spalling

the development of spalls.

Span

distance between the support reactions of members carrying transverse loads.

Spatterdash

a rich mixture of portland cement and coarse sand thrown onto a background by a trowel, scoop, or other appliance so as to form a thin, coarse-textured, continuous coating; as a preliminary treatment before rendering, it assists bond of the undercoat to t

Specific Gravity Factor

the ratio of the mass of aggregates (including moisture), as introduced into the mixer, to the effective volume displaced by the aggregates.

Specific Heat

the amount of heat required per unit mass to cause a unit rise of temperature over a small range of temperature.

Specific Surface

the surface area of particles or of air voids contained in a unit mass or unit volume of a material.

Specification (in ASTM)

an explicit set of requirements to be satisfied by a material, product,system, or service.

Specified Compressive Strength

compressive strength of concrete used in design.

Specified Concrete Compressive Strength

the specified resistance of a concrete specimen to axial compressive loading used in design calculations and as the basis for acceptance of concrete used in the work.

Specified Concrete Equivalent Strength

in-place concrete compressive strength adjusted by correction factorsthat can be directly substituted into conventional strength equations with customary strength reduction factors.

Specimen

a piece or portion of a sample used to make a test.

Splitting Tensile Strength

tensile strength of concrete determined by a splitting tensile test (also called indirect tension strength).

Splitting Tensile Test

a test for tensile strength in which a cylindrical specimen is loaded to failure in diametral compression applied along the entire length (also called indirect tension test).

Spray Drying

a method of evaporating the liquid from a solution or dispersion by spraying it into a heated gas.

Spread Footing

a generally rectangular prism of concrete, larger in lateral dimensions than the column or wall it supports, to distribute the load of a column or wall to the subgrade.

Spreader

(1) a piece of lumber approximately 1 by 2 in. (25 by 50 mm) cut to the thickness of a wall or other formed element and inserted in the form to hold it temporarily at the correct dimension against tension of form ties;
(2) a device consisting of reciproc

Spud Vibrator

a vibrator with a vibrating casing or a vibrating head used to consolidate freshly placed concrete by insertion into the mass.

Standard Curing

exposure of test specimens to specified conditions of moisture andtemperature.

Standard Fire Test

the test prescribed by ASTM E119.

Standard Hook

a hook at the end of a reinforcing bar made in accordance with a standard.

Standard Hooked Bar

a reinforcing bar with the end bent into a hook of prescribed geometry to provide anchorage.

Standard Sand

silica sand, composed almost entirely of naturally rounded grains of nearly pure quartz, used for preparing mortars in the testing of hydraulic cements.

Standard Time-temperature Curve

the graphic time table for application of temperature to a material ormember for the ASTM E119 fire test.

Static Load

(1) the mass of a single stationary body or the combined masses of stationary bodies in a structure (such as the load of a stationary vehicle on a roadway);
(2) during construction, the combined mass of forms,stringers, joists, reinforcing bars, and the

Stationary Hopper

a container used to receive and temporarily store freshly mixed concrete.

Steam Curing

(1) curing of concrete, mortar, grout, or neat-cement paste in watervapor at atmospheric or higher pressures and at temperatures between approximately 100 and 420°F (40 and 215°C). (See also atmospheric- pressure steam curing, and autoclave curing.)

Stearic Acid

a white crystalline fatty acid, obtained by saponifying tallow or other hard fats containing stearin. (See also butyl stearate).

Stepped Footing

a step-like support consisting of prisms of concrete of progressively diminishing lateral dimensions superimposed on each other to distribute the load of a column or wall to the subgrade.

Sticky Cement

finished cement that develops low or zero flowability during or after storage in silos or after transportation in bulk containers or hopper-bottom cars; may be caused by interlocking of particles, mechanical compaction, or electrostatic attraction between

Stiffness

resistance to deformation.

Straight-line Theory

an assumption in reinforced-concrete analysis according to which the strains in a member under flexure are assumed to vary in linear proportion to the distance from the neutral axis.

Straightedge

(1) a rigid, straight piece of either wood or metal used to strikeoff or screed a concrete surface to proper grade or to check the planeness of a finished grade (see also rod, screed, and strikeoff);
(2) a highway tool for truing surfaces instead of a bu

Strain

the change in length per unit of length, in a linear dimension of a body.

Stratification

(1) the separation of overwet or overvibrated concrete into horizontal layers with increasingly lighter material toward the top; water, laitance, mortar, and coarse aggregate tend to occupy successively lower positions in that order;
(2) a layered struct

Stratling’s Compound

dicalcium aluminate monosilicate-8-hydrate, a compound that has been found in reacted lime-pozzolan and cement-pozzolan mixtures.

Strength

a generic term for the ability of a material to resist strain or rupture induced by external forces. (See also concrete compressive strength, fatigue strength, flexural strength, shear strength, splitting tensile strength, tensile strength, ultimate stren

Strength-design Method

a design method that requires service loads to be multiplied by load factors and computed nominal strengths to be multiplied by strength reduction factors.

Stress

force per unit area.

Stress Corrosion

corrosion of a metal either initiated or accelerated by stress.

Stress Relaxation

the time-dependent decrease in stress in a material held at constant strain. (See also creep.)

Stress-strain Diagram

a diagram in which corresponding values of stress and strain are plotted against each other.

Stressing End

in prestressed concrete, the end of the tendon at which the load is applied when tendons are stressed from one end only.

Strikeoff

to remove concrete in excess of that which is required to fill the form evenly or bring the surface to grade; performed with a straightedged piece of wood or metal by means of a forward sawing movement or by a power- operated tool appropriate for this pur

Strip

(1) to remove formwork or a mold;
(2) a long thin piece of wood, metal, or other material. (See also demold and stripping.)

Strip Foundation

a continuous foundation wherein the length considerably exceeds the breadth.

Stripper

a liquid compound formulated to remove coatings by either chemical action, solvent action, or both.

Stripping

the removal of formwork or a mold. (See also demold.)

Strongback

a frame attached to the back of a form or precast structural member to stiffen or reinforce the form or member during concrete placing operations or handling operations.

Structural Concrete

plain or reinforced concrete in a member that is part of a structural system required to transfer gravity loads, lateral loads, or both, along a load path to the ground.

Structural End-point

the acceptance criterion of ASTM E119, which states that the specimen shall sustain the applied load without collapse.

Structural Lightweight Concrete

structural concrete made with lightweight aggregate and having an air-dry density of not more than 115 lb/ft 3 (1850 kg/m 3 ).

Stucco

a portland cement-based plaster used for coating exterior walls and other exterior surfaces. (See also plaster.)

Stud

(1) member of appropriate size and spacing to support sheathing of concrete forms;
(2) a headed steel device used to anchor steel plates or shapes to concrete members.

Subbase

the layer in a pavement system between the subgrade and the base course, or between the subgrade and the pavement.

Subgrade

the soil prepared and compacted to support a structure or a pavement system.

Substrate

any material on the surface of which another material is applied.

Substructure

all of that part of a structure below grade.

Sulfate Attack

a chemical reaction, physical reaction, or both, between sulfates usually in soil or ground water and concrete or mortar.

Sulfate Resistance

ability of concrete or mortar to withstand sulfate attack. (See also sulfate attack.)

Sulfate-resistant Cement

portland cement that is low in tricalcium aluminate, to reduce susceptibility of concrete to attack by dissolved sulfates in water or soils, referred to as ASTM C150 Type V cement.

Superplasticizer

see high-range water-reducing admixture (preferred term).

Superstructure

all of that part of a structure above grade.

Supersulfated Cement

a hydraulic cement made by intimately intergrinding a mixture of granulated blast-furnace slag; calcium sulfate; and a small amount of lime, portland cement, or portland cement clinker; so named because the equivalent content of sulfate exceeds that for p