What is anchoring?
What anchoring is, how an anchor holds in concrete and masonry, and why a fastening's capacity depends on more than the anchor itself.
Anchoring guides
Technical guides to post-installed anchors in concrete: how throughbolts (wedge anchors), chemical anchors, concrete screws and other anchor types transfer load, how they are installed, and how they are designed to EN 1992-4 using European Technical Assessments (ETAs).
29 guides
Types of concrete anchors
Cast-in and post-installed anchors for concrete, classified by how they transfer load, with the practical consequences of each system.
Tension, shear and combined loading explained
How loads on a fixture become tension and shear forces on each anchor, how moments and stand-off gaps arise, and how combined tension and shear are verified.
How anchors transfer loads into concrete
How friction, bearing and bond transfer anchor forces into concrete, why concrete tensile strength limits resistance, and how shear and the supporting member enter the load path.
Cracked vs uncracked concrete
Why concrete at an anchor must normally be assumed cracked, how uncracked concrete is verified to EN 1992-4, and how cracks reduce anchor resistance.
Anchor dimensions and notation explained
Read anchor dimensions correctly, including diameter, drill-hole size, effective embedment, hole depth and fixture thickness.
How concrete strength and geometry affect anchor resistance
How concrete strength, effective embedment, edge distance, spacing and member thickness change the resistance of an anchor and its governing failure mode.
Characteristic, design and recommended loads explained
The difference between action effects and anchor resistance, how partial factors convert characteristic values into design values, and what a manufacturer's recommended (safe working) load represents.
Mechanical vs chemical anchors: selection considerations
Compare mechanical and resin bonded anchors by loading time, embedment, edge distance, installation conditions and performance in service.
Throughbolt (wedge) anchors explained
How tightening sets a throughbolt (wedge anchor), how anchor length suits fixture thickness and embedment, which installation conditions control setting, and which failure modes limit its resistance.
Heavy-duty sleeve anchors explained
The roles of the bolt, shear sleeve, collapsible section and expansion assembly of a heavy-duty sleeve anchor, and how setting, dimensions and head version affect its use.
Drop-in anchors explained
How a setting tool expands a drop-in anchor, how the bolt or threaded rod is matched to it, and which installation and concrete conditions limit its use.
Undercut anchors explained
How an undercut anchor transfers tension by bearing in a recess, how the recess is formed, how complete setting is verified and which failure modes limit its resistance.
Concrete screw anchors explained
How a concrete screw transfers load through threads cut into the hole wall, what controls installation, and how embedment, adjustment and reuse affect its use.
Resin bonded (chemical) anchors explained
How a resin bonded (chemical) anchor transfers load by bond, how anchoring differs from post-installed rebar connections, and how hole preparation, curing, temperature and sustained load affect it.
What is an ETA for an anchor?
What a European Technical Assessment (ETA) records for an anchor, who issues it, how its data are used in design and how it relates to the declaration of performance and CE marking.
Installation arrangements for concrete anchors
How pre-positioned, through-fixing and stand-off installations determine the drilling sequence, fixture clearance hole, anchor length and shear transfer.
Drilling methods for post-installed anchors
How hammer drilling, hollow-bit drilling with dust extraction and diamond core drilling differ in cutting action, hole diameter, wall texture and cleaning, and which method the ETA permits.
Why drill-hole cleaning matters for bonded anchors
How drilling dust, moisture and slurry reduce the bond of resin anchors, and which cleaning steps and hole conditions the ETA specifies.
Anchor installation torque explained
What the installation torque does in expansion, bonded, screw and undercut anchors, how it relates to preload and clamping force, why preload falls after installation, and how clamping affects load transfer.
How an anchor design check works
The stages of an anchor design to EN 1992-4, from actions and connection geometry to anchor forces, resistance for each failure mode, displacement, the concrete member and the installation requirements passed to site.
Anchor failure modes under tension
The tension failure modes verified in EN 1992-4 (steel failure, pull-out, combined pull-out and concrete failure, concrete cone, splitting and blow-out), what limits each one and where its resistance comes from.
Anchor failure modes under shear
The shear failure modes verified in EN 1992-4 (steel failure with and without lever arm, pry-out and concrete edge failure), how shear is transferred into the concrete and what limits each mode.
How an anchor group shares load
How EN 1992-4 distributes tension, shear and torsion from a fixture to the anchors of a group, and how eccentricity, fixture stiffness and hole clearance change the load on each anchor.
Anchor displacement and connection stiffness
What makes up the displacement of an anchor and of a complete connection, how the European Technical Assessment (ETA) and EN 1992-4 treat it, and why ductile behaviour matters.
Corrosion and anchor materials explained
How exposure determines the steel and corrosion protection of an anchor, how zinc coatings and stainless steels resist corrosion, and the local corrosion mechanisms that can weaken a fastening without visible warning.
Sustained loading, creep and fatigue explained
How sustained loads cause creep of bonded anchors, how repeated loads cause fatigue, and how EN 1992-4 and the European Technical Assessment (ETA) account for both.
Fire resistance of anchors explained
How fire heats the anchor, fixture and concrete, which failure modes govern under fire exposure, and how EN 1992-4 and the European Technical Assessment (ETA) give fire resistances.
Anchors under seismic loading
How an earthquake loads anchored equipment and structural connections, how cracking and load reversal affect anchors, and how seismic performance categories C1 and C2 and the EN 1992-4 design options apply.