Construction Chemical Glossary: A–Z

This construction chemical glossary defines the technical terms used across our data sheets, guides and safety documentation — a quick reference for anyone working with injection resins, waterproofing, ground stabilisation or structural repair systems.

Acrylate solution

A liquid resin system (such as Galaxie AC200/AC300) used for ultra-low viscosity injection into very fine cracks and honeycombed concrete. Non-toxic and non-flammable.

Admixture

A material added to concrete during mixing (other than cement, water and aggregate) to modify its properties, commonly used to improve waterproofing, workability, strength or set time.

Bonding agent

A material applied to an existing concrete surface to improve adhesion between it and a new layer of concrete, mortar or repair material.

Carbonation

A chemical reaction between atmospheric CO₂ and concrete that reduces its alkalinity over time, potentially leading to corrosion of embedded steel reinforcement. Relevant when assessing why a drilled hole or packer may be failing to seat properly in older, deteriorated concrete.

Catalyst

The component that triggers a resin's curing reaction. Catalyst dosage can be adjusted to speed up or slow down cure time depending on site temperature.

Compressive strength

A material's ability to withstand loads that reduce its size, typically measured in MPa. A key performance metric for structural repair grouts and epoxies.

Curtain grouting

A technique of injecting grout into a series of closely spaced boreholes to create a continuous, low-permeability barrier underground, commonly used in dam, tunnel and foundation construction to control groundwater movement.

Densifier

A chemical treatment (often silicate or siloxane-based) applied to concrete surfaces to react with free lime and harden the surface, improving abrasion resistance and reducing dusting.

Efflorescence

white, powdery deposit that forms on concrete or masonry surfaces when water carries soluble salts to the surface and evaporates, leaving the salts behind. Often an indicator of ongoing water penetration.

Elongation

A measure of how much a cured resin can stretch before breaking, expressed as a percentage. High-elongation products (like Galaxie PU SF) are suited to joints and cracks that continue to move after repair.

EST (Extended Set Time)

A slower-curing grade of resin, used in hot conditions or on longer injection runs where a standard-speed product would gel before the job is finished.

Exothermic reaction

A chemical reaction that releases heat as it occurs. Resin curing is exothermic. In mass applications or hot weather, excess heat generation can accelerate set time or affect performance.

Grout

A fluid or semi-fluid material used to fill gaps, voids or spaces, ranging from cementitious grouts for structural gap-filling to chemical resin grouts for waterproofing and ground stabilisation.

Honeycombing

Poorly compacted concrete with visible voids, resembling a sponge. Has no defined crack path, requiring tighter packer spacing and a low-viscosity resin to properly fill the matrix.

Hydrophilic

A resin that reacts with and is attracted to water. Hydrophilic resins actually need moisture present to cure and expand properly, making them well suited to wet or actively leaking cracks.

Hydrophobic

A resin that repels water. Hydrophobic foams expand on contact with water but can be washed away by very fine, high-flow leaks before they fully react.

Hydrostatic pressure

The pressure exerted by standing or groundwater against a structure, common in deep basements and water-retaining structures. High hydrostatic pressure requires relief drilling before injection to bring pressure down to a workable level.

Integral waterproofing

Waterproofing achieved by adding an admixture directly into the concrete mix, so the waterproofing property is built into the material itself rather than applied as a surface coating afterward.

Isocyanate

A reactive chemical group found in polyurethane resins (including TDI-based products like Galaxie PU SF). Isocyanates require supplied-air respiratory protection in enclosed spaces and are subject to health monitoring requirements under Australian WHS regulations.

Load transfer

The process of transferring structural load across a crack, joint or repaired section, restoring the element's original structural continuity. Rigid epoxy systems are used specifically where load transfer across a crack face is required.

MPa (Megapascal)

A unit of pressure used to describe injection pump working ranges and material strength. 1 MPa equals 10 bar.

Packer

A mechanical or adhesive-bonded fitting installed into a drilled hole (or bonded to the surface) that allows resin to be injected directly into a crack under controlled pressure.

Permeability

A measure of how easily water or vapour can pass through a material. Waterproofing admixtures and surface treatments work by reducing the permeability of concrete.

Pot life

The length of time a mixed, multi-component product (such as a two-component epoxy) remains workable before it begins to cure and can no longer be applied effectively.

Slab jacking

A technique for lifting and levelling a settled concrete slab by injecting expanding polyurethane foam beneath it, filling voids and raising the slab back to its original position without full replacement..

Soil consolidation

The process of compacting or stabilising loose or weak soil, often achieved by injecting expanding polyurethane resin into the ground to fill voids and increase load-bearing capacity.

Spalling

The breaking away of concrete from a structure's surface, often caused by corrosion of embedded steel reinforcement, freeze-thaw damage, or impact. A common indicator that structural repair is needed.

Static mixer

A device that mixes two-component resins (such as epoxy) in the correct ratio as they're dispensed, ensuring consistent, properly cured material without manual pre-mixing.

TDI (Toluene Diisocyanate)

A specific isocyanate compound used in some high-performance polyurethane foams, including Galaxie PU SF, valued for its exceptional elongation properties.

Thixotropic

Describes a material that is thick or gel-like at rest but flows more easily when agitated or under pressure, a useful property for grouts and resins applied to vertical or overhead surfaces, since it resists sagging.

Viscosity

A measure of a resin's thickness or resistance to flow. Low-viscosity resins (near-water viscosity) are needed to penetrate very fine cracks below 0.2 mm.

VOC (Volatile Organic Compound)

Chemical compounds that evaporate readily at room temperature. Low-VOC products are preferred in enclosed spaces and environmentally sensitive applications, including near potable water infrastructure.

Void filling

The process of injecting resin or grout into an empty space beneath a slab, behind a wall, or within a structure to restore support and prevent further settlement.

Waterstop

A strip or barrier (often PVC, rubber or bentonite-based) embedded within a construction or expansion joint to prevent water passing through the joint. Waterstop repair involves resealing this barrier where it has failed.

WES (Workplace Exposure Standard)

The maximum allowable airborne concentration of a substance a worker can be exposed to over a set period, set under Australian WHS regulations. Relevant to isocyanate-based PU products requiring ventilation and respiratory protection controls.

Workability

A measure of how easily a fresh concrete, grout or mortar mix can be placed, compacted and finished. Admixtures are often used to improve workability without adding excess water.

Looking for something more specific?

Contact our technical team →