AnchorDesign360™

The temperature range describes the service temperatures the bonded anchor is assessed for in its ETA: the short-term value covers brief peaks (e.g. diurnal cycles), the long-term value the sustained base-material temperature. The characteristic bond resistance τ_Rk declared by the ETA depends on the selected range.

Pick the smallest range that envelopes both temperatures expected at the fastening over the working life — a member permanently warmer than the long-term cap needs the next range even if the short-term maximum is not exceeded. A higher range generally means lower declared bond values.

A stand-off exists when the base plate does not bear directly on the concrete — the gap e_b is the “Base plate stand-off” below. The installation type decides how the anchors carry SHEAR (EN 1992-4 6.2.2.3 / 7.2.2.3.2) and how the anchor forces are distributed:

The lever-arm steel check usually governs stand-off designs — an unfilled gap of even a few bolt diameters can cut the shear capacity by an order of magnitude.

Closely spaced surface reinforcement in the base member (spacing < 150 mm, or < 100 mm for Ø ≤ 10 mm) can split off a concrete shell between the bars and the surface. For shallow embedments (h_ef < 100 mm) the shell-spalling factor ψ_re,N = 0.5 + h_ef/200 ≤ 1.0 then reduces the concrete cone, combined pull-out, splitting and pry-out resistances (EN 1992-4 7.2.1.4(5)).

Leave unticked when there is no reinforcement, or its spacing is ≥ 150 mm (any diameter) or ≥ 100 mm (Ø ≤ 10 mm) in both directions. At h_ef ≥ 100 mm the factor is 1.0 either way.

Tick when the member's reinforcement is designed to resist the splitting forces and to limit the crack width to w_k ≤ 0.3 mm. The splitting failure verification may then be omitted.

The declaration acts only together with cracked concrete — the clause requires the concrete cone and pull-out checks to assume the cracked state.

Edge reinforcement (straight bars per Figure 7.10) combined with closely spaced stirrups or a wire mesh (spacing a ≤ 100 mm and a ≤ 2·c₁) raises the concrete edge resistance by ψ_re,V = 1.4 in cracked concrete (EN 1992-4 7.2.2.5(13)).

In uncracked concrete the benefit is already contained in the base value — the factor stays 1.0 and the tick has no effect.

EN 1992-4, Figure 7.10 a — surface reinforcement to take up shear forces

Stirrups or loops around each fastener, designed to carry the tension load across the concrete break-out cone. When active with a valid anchorage length l₁, the concrete cone verification is replaced by two checks: steel of the legs (Eq. 7.31) and their anchorage inside the assumed cone (Eq. 7.32).

Detailing per 7.2.1.2(2): ribbed bars ≤ 16 mm around every fastener, only legs within 0.75·h_ef effective, l₁ ≥ 4Ø for hooks/bends/loops or 10Ø for straight legs. Relying on supplementary reinforcement also reduces pry-out by the factor 0.75 (Eq. 7.39) and, when only one direction is reinforced, switches the concrete N–V interaction to Formula (7.57).

EN 1992-4, Figure 7.2 a — supplementary reinforcement (1: stirrups, 2: surface reinforcement) to take up tension loads

Surface reinforcement (Fig. 7.10 a) or stirrups/loops in contact with the fastener (Fig. 7.10 b, c) that carry the shear towards the edge. The concrete edge verification of the reinforced direction is then replaced: the reinforcement is designed for N_Ed,re = V_Ed·(1 + e_s/z), Formula (6.6).

The steel check (7.51) uses k₁₀ = 1.0 for surface reinforcement and 0.5 for loops; the surface form additionally needs the anchorage length l₁ inside the edge break-out body (7.52/7.53). Reliance reduces pry-out by 0.75 and, with reinforcement in one direction only, the interaction uses Formula (7.57) with k₁₁ = 2/3.

EN 1992-4, Figure 7.10 b, c — stirrups / loops in contact with the fastener

α_sus is the sustained fraction of the tension load: α_sus = N_Ed,sus/N_Ed, where N_Ed,sus includes permanent actions and the permanent part of variable actions (dead load, prestress, long-term settlement effects). Bonded anchors creep under sustained tension, so the bond resistance is reduced by ψ_sus = ψ⁰_sus + 1 − α_sus ≤ 1.0 (Formula 7.14b), applied inside the combined pull-out–cone check and its pry-out leg.

ψ⁰_sus comes from the product's ETA and depends on the temperature range and working life (typically 0.6–0.99). With α_sus ≤ 1 − ψ⁰_sus the factor stays 1.0 — a fully short-term load loses nothing; a fully sustained load (α_sus = 1) reduces the bond to ψ⁰_sus·τ_Rk. Steel and concrete-cone modes are not affected.

The joint between existing and new concrete is a cold joint: the longitudinal shear acting across it must be transferred by adhesion, friction and the reinforcement crossing the interface. “no” omits this verification — for joints verified elsewhere or not loaded in shear.

On the end-anchorage route a shear-loaded joint must declare its transfer path: pick a verification method here, or “transferred externally” when a shear key / dowels carry it (recorded in the result as your declaration). With shear present and “no” selected, the result is marked failed until the path is declared.

EN 1992-1-1 6.2.2/6.2.3 is the strut-and-tie route for members dominated by bending: the concrete shear resistance V_Rd,c (6.2a/b), reduced by the roughness knock-down c/0.5. EN 1992-1-1 6.2.5 checks v_Rdi = c·f_ctd + μ·σ_n + ρ·f_yd·(μ·sin α + cos α) directly at the interface — for shear/compression-dominated joints.

The joint roughness supplies the coefficient pair c / μ per 6.2.5(2): very smooth 0.025/0.5, smooth 0.20/0.6, rough (≥ 3 mm profile) 0.40/0.7, indented 0.50/0.9 — it is used only by this check.

Stress acting across the drilled bars in the existing member — bearing pressure from loads above the anchorage (compression, −) or restraint stresses pulling the zone apart (tension, +). Through Ω_p,tr (Eq. 4.11a) it scales the bond-splitting resistance: transverse tension opens the splitting cracks and cuts the bond by up to 30 % at p_tr = f_ctm; transverse compression clamps the bars and raises it.

0 (the default) means no effect. Only the bond-splitting verification is affected — steel and concrete cone are not. Enter a negative (clamping) value only for a pressure that is reliably permanent.

A bending moment presses the section's compression resultant onto the concrete beside the anchorage, clamping the potential break-out cone. The cone resistance grows by ψ_M,N = 2 − z/(1.5·l_b) ≥ 1.0 — the closer the compression sits to the bars (small z), the larger the benefit, up to ×2.

Blank fields (the default) derive the lever arm z and the ratio |C_Ed|/N_Ed from the interface cross-section analysis. Fill them only to impose values from your own frame analysis. The benefit applies only when |C_Ed|/N_Ed ≥ 0.8, z is known and no edge lies closer than 1.5·l_b — otherwise ψ_M,N = 1.0.

Pick the method by the load situation at the interface:

EOTA TR 069 is valid only in continuous joints: a beam-to-column frame corner (L-joint) must be designed with the EN 1992-1-1 strut-and-tie method.

Classifies the surface of the cold joint between the existing and the new concrete. It sets the adhesion coefficient c and the friction coefficient μ of the interface-shear verification; the 6.2.2/6.2.3 route applies the same c as its c/0.5 knock-down.

Roughening the joint (raking, high-pressure water jetting, exposed aggregate) is the cheapest way to raise the interface capacity — a very smooth formwork joint carries almost no adhesion.

EN 1992-1-1, Figure 6.9 — indented construction joint

For a beam or column joint checked with method 6.2.2, the shear resistance depends on whether the NEW member carries shear reinforcement (links / stirrups) across the joint region:

Select no when the new member has no links crossing the joint — assuming links that are not there overestimates the shear capacity by an order of magnitude.

Shear across the section shifts the tension line: the tension chord carries an additional longitudinal force ΔF_td = V_Ed·cot θ (cot θ = 1.0). For a discrete rebar connection the full shift applies — not the 0.5·V·cot θ of a distributed beam web.

The shift is split per reinforcement layer: each of the n layers carries ΔF/n shared over its bars, raising their steel stress σ_sd and with it the required lap or anchorage length. The transverse shear transfer across the joint still needs its own path — a roughened surface, dowels, or the interface-shear check.

A drilled bar cannot be guaranteed to sit directly beside the existing bar it laps onto. This option designs for the worst permitted position: a non-contact splice with a clear distance e = bar spacing / 2 (columns: max(s_x, s_y)/2).

Per EN 1992-1-1 8.7.2(3), a lap with e beyond 4Ø (max 50 mm) is lengthened by the excess: l_0,e = e − min(4Ø, 50 mm), added to the lap length l₀ and the installation length l_v. Untick only when the drill position is controlled on site and the actual spacing is entered.

Enter design values at the ultimate limit state (ULS) — actions already factored and combined to EN 1990. The verification compares them directly against the design resistances; no further partial factor is applied to what you type here.

The methods used here — EN 1992-4 (main body), EOTA TR 069 and EOTA TR 023 / EN 1992-1-1 — cover predominantly static actions, i.e. static and quasi-static loading: self-weight, imposed and wind loads, earth and water pressure, temperature and shrinkage effects, and slowly applied or rarely repeated variable actions.

Not covered by this calculation: seismic actions (EN 1992-4 Annex C, performance categories C1/C2), fatigue (Annex B), and impact or shock loading. Each of those needs the product to be assessed for that action in its ETA and a design check beyond the scope of this tool. Use these results for predominantly static design situations only.

Sign convention: N is positive in tension and negative in compression; shear and moment components are taken about the axes shown on the 3D model.

Stirrups along the lap confine the concrete and take up the transverse tension forces of the splice; the lap length may then be reduced by α₃ = 1 − K·λ ≥ 0.7, with λ = (ΣA_st − ΣA_st,min)/A_s counted over the stirrups within the lap zone and K set by the stirrup-leg position (Fig. 8.4).

“yes” opens the stirrup fields: Ø and spacing give the countable ΣA_st over the assumed lap length, the cover sets where the first stirrup sits in the 3D model. “no” takes no confinement credit — α₃ = 1.0 — which is always conservative.

EN 1992-1-1, Figure 8.4 — values of K for beams and slabs

K_tr = (n_t·A_st)/(n_b·Ø·s_b) ≤ 0.05 (Eq. 4.12, per fib Model Code 2010): n_t — number of legs of confining reinforcement crossing a potential splitting surface; A_st — cross-sectional area of one stirrup leg; n_b — number of anchored bars in that splitting surface; s_b — spacing of the confining reinforcement. The term k_m·K_tr is added inside the bond-splitting resistance, Eq. (4.11a), and stays capped by the ETA bond limit (4.11b/c).

Count only links of the EXISTING member around the anchorage — not new-member stirrups. “no” sets K_tr = 0 (always conservative). Independent of “Dense existing reinforcement”, which reduces the concrete cone (ψ_re,N) for shallow embedments.

EOTA TR 069, Figure 4.2 — reduced effectiveness of links (fib Bulletin 72)

The design bond strength f_bd = 2.25·η₁·η₂·f_ctd depends on the bond-condition coefficient η₁: 1.0 in “good” conditions, 0.7 otherwise — poor bond lengthens anchorages and laps by roughly 40 %.

Good conditions per EN 1992-1-1 Figure 8.2: all bars inclined 45–90° to the horizontal, and horizontal bars in members ≤ 250 mm deep, in the bottom 250 mm, or at least 300 mm below the top surface. Anything else — notably top bars of deep members — is “poor”. The selection feeds f_bd of both the drilled bar and the existing cast-in bar.

EN 1992-1-1, Figure 8.2 — description of bond conditions