ICRI CSRT Grade 1 flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Water/cementitious ratio

Ratio of water mass to total cementitious material mass in a concrete mix. Higher values increase capillary porosity and permeability, reducing strength and durability.

Carbonation

Reaction of atmospheric carbon dioxide with calcium hydroxide in concrete, forming calcium carbonate and lowering pore-solution pH below the level that protects reinforcing steel.

Chloride threshold

The chloride concentration at the steel surface above which the passive film breaks down and corrosion initiates. Commonly cited near 0.4 percent by mass of cement.

Alkali-silica reaction

Expansive reaction between reactive silica in aggregate and alkali hydroxides in pore solution. The resulting gel absorbs water and swells, cracking the concrete.

Sulfate attack

Chemical deterioration in which external sulfates react with cement hydrates to form ettringite and gypsum, causing expansion, cracking, and softening of the concrete.

Delayed ettringite formation

Internal sulfate attack caused by curing concrete above roughly 70 degrees Celsius early in life, followed by moisture exposure, producing later expansion and cracking.

Freeze-thaw damage

Deterioration from repeated freezing and thawing of water in saturated pores. Air entrainment creates relief voids that accommodate ice expansion and reduce damage.

Shrinkage-compensated repair mortar

Cementitious repair material formulated to expand slightly during curing, offsetting drying shrinkage. Used in large patches where restrained shrinkage would otherwise crack or debond.

Polymer-modified mortar

Repair mortar with latex or redispersible polymer added to improve bond, tensile strength, and impermeability. Polymer dosage is stated as a percentage of cement weight.

Epoxy repair material

High-strength, low-permeability, essentially non-shrinking material with a higher modulus and thermal coefficient than concrete. Unsuitable for damp substrates or vapor-transmitting applications.

Bonding agent

Material applied between substrate and repair to improve adhesion. Cementitious slurry requires a saturated-surface-dry substrate; epoxy systems require a dry, sound surface.

Saturated-surface-dry

Substrate condition in which pores are filled with water but no free water remains on the surface. Required for cementitious repair materials to prevent water loss or dilution.

Cathodic protection

Electrochemical technique that applies a small direct current to shift steel potential into the immune range, stopping corrosion. Requires electrical continuity of the reinforcement.

Hydrodemolition

High-pressure water jetting used to remove concrete. It avoids microcracking in the remaining substrate and can remove chloride-contaminated concrete to a controlled depth.

Feather edge

A thin, tapered edge of repair material that terminates at zero thickness. It is weak and prone to failure, so repair edges are cut square to a minimum depth.

SSPC-SP 10

Near-white abrasive blast cleaning standard for steel. Used for repair work where a high degree of cleanliness is required before applying protective coatings or repair material.

Acid-soluble chloride

Chloride content measured by acid extraction of a concrete sample, reported as a percentage of cement or concrete mass and compared against a specified corrosion threshold.

Sounding

Technique of tapping concrete with a hammer to detect delamination or voids. A hollow sound indicates a debonded layer that must be removed before repair.

Dry-pack mortar

Low-water-content cementitious mix tamped into small, deep patches. Its low water content minimizes shrinkage but requires a clean, rough, saturated-surface-dry substrate.

Shotcrete placement

Pneumatically applied concrete or mortar for large-volume repairs. Requires a competent nozzleman and typically uses a lower water/cementitious ratio than cast-in-place concrete.

Epoxy injection

Method of repairing structural cracks by injecting low-viscosity epoxy under pressure. Suitable for cracks roughly 0.2 to 0.3 millimeters and wider that are not actively moving.

Curing compound

Membrane-forming liquid applied to fresh concrete to retard moisture loss. Must be compatible with subsequent coatings and finishes, since some compounds interfere with adhesion.

Thixotropic repair material

Material that resists sagging when placed on vertical or overhead surfaces but flows when agitated. Used where standard mortars would slump out of the repair area.

Half-cell potential

ASTM C876 test that maps corrosion activity by measuring electrical potential of steel against a reference electrode. Values more negative than about -350 millivolts indicate high corrosion probability.

Cover meter survey

Non-destructive test using electromagnetic induction to locate reinforcement and measure concrete cover depth. Insufficient cover is a leading cause of chloride-induced corrosion.

Pull-off test

Method for measuring tensile bond strength of a repair by attaching a dolly and pulling it. Failure should occur in the substrate rather than at the bond line.

Slant shear test

ASTM C882 laboratory method that evaluates bond strength between a repair material and a concrete substrate by testing a slanted composite specimen in shear.

Chain dragging

Delamination survey technique in which a chain is dragged across a concrete surface. A dull or hollow sound indicates a debonded layer requiring removal.

Respirable crystalline silica

Fine silica dust generated by cutting, grinding, and blasting concrete. It causes silicosis; controls include wet methods, ventilation, and respiratory protection.

Confined space entry

Entry into a space with limited access and potential atmospheric hazards such as tanks or vaults. Requires atmospheric testing, ventilation, a permit, and a rescue plan.

Lead-safe work practices

Procedures for working on structures with lead-based paint, including containment, worker protection, and waste characterization, required under OSHA's lead standard.

Repair documentation package

Record of as-built drawings, material submittals, test reports, daily field reports, and photographs that documents the repair scope and verifies quality compliance.