Concrete Waterproofing Glossary

Ramming

a form of heavy tamping of concrete, grout, or the like by means of a blunt tool forcibly applied. (See also dry pack and tamping.)

Raveling

the wearing away of the concrete surface caused by the dislodging of aggregates particles.

Raw Mix

blend of raw materials ground to desired fineness, correctly proportioned,and blended ready for burning, used in the manufacture of cement clinker.

Rayleigh Wave

a surface wave in which the particle motion is elliptical and effective penetration is less than one wavelength.

aggregate containing substances capable of reacting chemically with the products of solution or hydration of the portland cement in concrete or mortar under ordinary conditions of exposure, resulting in some cases in harmful expansion, cracking, or staini

Reactive Silica Material

several types of materials that react at high temperatures with portland cement or lime during autoclaving, includes pulverized silica, natural pozzolan, and fly ash.

Ready-mixed Concrete

concrete manufactured for delivery to a purchaser in a fresh state. (See also central-mixed concrete, shrink-mixed concrete, and transit-mixed concrete. )

Rebar

colloquial term for reinforcing bar. (See also reinforcement.)

Rebound

shotcrete materials or wet shotcrete that bounces away from the surface against which the shotcrete is being projected.

Rebound Hammer

an apparatus that provides a relative indication of the strength or hardness of concrete based on the rebound distance of a spring-driven mass after it impacts a rod in contact with the concrete surface.

Recycled Concrete

hardened concrete that has been processed for reuse, usually as aggregate.

Reference Standards

standardized mandatory language documents of a technical society, organization, or association, including the building codes of local or state authorities that are referenced in the contract documents or other standardized documents.

Refractories

materials, usually nonmetallic, used to withstand high temperatures.

Refractoriness

in refractories, the property of being resistant to softening or deformation at high temperatures.

Refractory

resistant to high temperatures.

Refractory Aggregate

aggregate that is resistant to high temperatures and suitable to produce refractory concrete.

Refractory Concrete

hardened hydraulic-cement concrete that that is suitable for use at temperatures between 600 and 2400°F (315 and 1315°C).

Refractory-insulating Concrete

refractory concrete having low thermal conductivity.

Regulated-set Cement

a hydraulic cement containing fluorine-substituted calcium aluminate,capable of very rapid setting.

Rehabilitation

the process of repairing or modifying a structure to a desired useful condition. (See also preservation, repair, and restoration.)

Reinforced Concrete

structural concrete reinforced with no less than the minimum amountof prestressing steel or nonprestressed reinforcement as specified in theapplicable building code.

Reinforcement

bars, wires, strands, fibers, or other slender elements that are embedded ina matrix such that they act together to resist forces.

Reinforcement Ratio

ratio of the area of the reinforcement to the area of the concrete at any section of a structural member. (See also percentage of reinforcement.)

Relative Humidity

the ratio of the quantity of water vapor actually present to the amountpresent in a saturated atmosphere at a given temperature expressed as a percentage.

Release Agent

material used to prevent bonding of concrete to a surface. (See also bond breaker and form oil.)

Remoldability

the readiness with which freshly mixed concrete responds to a remolding effort such as jigging or vibration, causing it to reshape its mass around reinforcement and to conform to the shape of the form. (See also remolding test.)

Render

to apply a coat of mortar by a trowel or float.

Repair

to replace or correct deteriorated, damaged, or faulty materials, components, or elements of a structure. (See also preservation, rehabilitation, and restoration.)

Repeatability

variability among replicate test results obtained on the same material within a single laboratory by one operator.

Reproducibility

variability among test results obtained on the same material in different laboratories.

Required Average Strength

the average strength of concrete used in mixture proportioning to ensurea high likelihood that the concrete will meet specified strength acceptance criteria.

Required Strength

strength of a member or cross section required to resist factored loads or related internal moments and forces in such combinations as are stipulated in the applicable code or specification.

Resetting (of Forms)

setting of forms separately for each successive lift of a wall to avoid offsets at construction joints.

Reshore

a temporary support placed against the bottom of a slab or other structural member immediately after the forms and original shores have been removed.

Resilience

the capability of a strained body to recover its size and shape after deformation.

Resin

(1) general term for a class of materials made by polymerization of organic liquid compounds called monomers;
(2) a plastic, viscous liquid, or monomer that is capable of hardening when mixed with appropriate catalysts or hardeners.

Restoration

the process of reestablishing the materials, form, and appearance of a structure to those of a particular era of the structure. (See also preservation, rehabilitation, and repair.)

Restraint (of Concrete)

restriction of free movement of fresh or hardened concrete following completion of placing in formwork or molds or within an otherwise confined space.

Retardation

(1) reduction in the rate of either setting, hardening, or both;
(2) an increase in the time required to reach time of initial and final setting or to develop early strength in a cementitious mixture. (See also retarder.)

Retarder

an admixture that delays the setting of a cementitious mixture. (See alsoretarding admixture.)

Retarding Admixture

an admixture that causes a decrease in the rate of hydration of the hydraulic cement and lengthens the time of setting.

Retemper

to add water and remix a cementitious mixture to restore workability to a condition in which the mixture is placeable or usable. (See also temper.)

Revibration

one or more applications of vibration to fresh concrete after completionof placing and initial consolidation but preceding initial setting of the concrete.

Ribbon Loading

method of batching concrete in which the solid ingredients, and sometimes also the water, enter the mixer simultaneously (also called ribbon feeding).

Rich Concrete

concrete of high cement content. (See also lean concrete.)

Rich Mixture

a concrete mixture containing a high proportion of cement.

Rigid Frame

a frame depending on moment in joints for stability.

Rigid Pavement

pavement that will provide high bending resistance and distribute loads to the foundation over a comparatively large area.

Rock Pocket

a porous, mortar-deficient portion of hardened concrete consisting ofcoarse aggregate and open voids. (See also honeycomb.)

Rod

(1) a tool that is used as a straightedge or screed to provide a uniform and even surface across a plaster coat usually by trimming to a ground or dot;
(2) a tool used as a guide for a scoring (combed) finish or similar repeating pattern finish;
(3) a s