Xponexus Engineering

RC Slab Design – Eurocode EN 1992

Extensive web-based reinforced concrete slab calculator covering one-way & two-way slabs, ULS/SLS reinforcement, punching shear, deflection control (simplified), crack width check (simplified), fire reduction factors, durability/cover, and detailing limits.

One-way Two-way (coeff.) Punching shear SLS cracks & deflection (simpl.)
Scope note (important):
This is a preliminary/design-assist calculator. It uses widely used EC2-style simplified models (rectangular stress block, lever-arm method, coefficient method for two-way slabs, simplified crack/deflection checks, simplified punching with optional shear reinforcement). Always verify with full EC2 clauses, National Annex, and project-specific detailing.

Materials & partial factors

Concrete/steel grades auto-fill strengths; adjust factors for National Annex.

Auto-fill
Concrete
Steel
Partial factors & stress block
Durability / cover

Slab system & geometry

Choose one-way or two-way. Define spans, supports, thickness, and openings (simplified).

System
Geometry
Spans
Openings (simplified)

If openings are significant, use FE/strut-and-tie or detailed EC2 methods. Here we apply an optional reduction factor.

Loads & combinations

Input characteristic loads and combination factors. Calculator forms ULS/SLS design actions.

ULS + SLS
Characteristic surface loads
Line loads (optional)

Line loads are converted to equivalent surface load on design strip for strip checks.

ULS factors (EN 1990 typical)
SLS combination factors
Combination model used: ULS: qd = γG·(gk_total) + γQ·qk (and optional line loads mapped to strip).
SLS: rare / frequent / quasi-permanent combinations are formed for service checks.

Analysis inputs (coefficients or manual actions)

For two-way slabs, use typical α-coefficients or override. Or enter MEd/VEd directly.

Coefficient method (two-way)

These are typical placeholders. Replace with your office standard / NA tables or validated coefficients.

Manual actions (if chosen)
Redistribution / moment pattern

Redistribution is simplified here (reduces MEd). Ensure ductility/rotation capacity requirements are met in EC2.

Punching shear (internal column)

Define column size, control perimeter, shear reinforcement options (simplified EC2 style).

Optional
Column / loaded area

Moment transfer effect is treated very simply as an amplification factor (β). For detailed design use EC2 method.

Control perimeter
Punching shear reinforcement
Concrete shear parameters

SLS: cracking & deflection (simplified)

Crack width via simplified steel stress; deflection via span/depth and effective stiffness proxy.

Crack control
Deflection control

Deflection check here is a pragmatic indicator (span/depth + stiffness proxy). For compliance, use EC2 7.4.3 full method.

Service moments (if needed)

Fire (EN 1992-1-2 – simplified reduction factors)

Apply simple capacity reductions to bending/shear; you can set kfi factors.

Optional
Fire inputs

This is a simplified approach (reduction factors). For real projects use tabulated data/500°C method/zone method as applicable.

Check summary

ULS + SLS + Punching
Bending (sagging)
Bending (hogging)
One-way shear
Min reinforcement
SLS (crack/defl.)
Punching
Fire (simpl.)

Utilisation ratios

Moments (ULS) – visual

Detailed engineering report

Assumptions and intermediate values are printed for transparency.