B01 · Intermediate · 1–2 hours
BS 8110 — one-way solid slab
Flexural design of a one-way slab strip with minimum/maximum steel, span/depth and bar spacing checks.
Tool: Education preview · Lesson: In preparation · Example: Built awaiting check · Workbook: Not applicable · Assessment: Not started
Outstanding before release: Engineering checker to verify clause mapping against a copy of BS 8110-1:1997 (+A3) and sign off v0.1.0. Cross-checked against TCC RCC11 v4.0 (see evidence).
Sources
| Role | Source | Note |
|---|---|---|
| Primary | BS 8110-1:1997 (+A1–A3): 3.4.4.4 (K, K′, z, As); 3.5.1/3.5.2 (slabs, analysis outside tool); Table 3.25 (minimum steel); 3.12.6.1 (maximum 4%); 3.4.6 / Tables 3.9–3.10, eq 7–8 (span/depth); 3.12.11.2.7 (maximum clear spacing 3d or 750 mm). | Withdrawn standard — education and legacy checks only (mapping awaiting checker verification) |
| Supporting | Cross-check reference: The Concrete Centre RCC11 Element Design v4.0 (external tool; not used in the implementation) | Comparison evidence only (mapping awaiting checker verification) |
"Primary" marks the governing clause for this exercise; "contextual" marks related clauses; "supporting" marks the design-method or data source outside the CDC. A CDC chapter mapping does not mean the CDC contains the equation used.
Prerequisites: none · Topics: Reinforced concrete
Lesson
Lesson in preparation. No content is published until it has been written and reviewed.
Calculator
Purpose: Flexural design of a one-way solid slab strip with deflection and bar-spacing checks.
Model: Singly reinforced rectangular section, b = 1000 mm.
Units: N, mm, kN, kNm; stresses in N/mm² Ranges: fcu 25–50 N/mm²; fy 250 / 460 / 500; βb 0.7–1.0
Equations: d = h − cover − Ø/2 ; K = M/(b d² fcu) ; K′ = 0.156 (βb ≥ 0.9) or 0.402(βb − 0.4) − 0.18(βb − 0.4)² ; z = d[0.5 + √(0.25 − K/0.9)] ≤ 0.95d ; As = M/(fy/γs · z) ; fs = 2fy As,req/(3 As,prov βb) ; MF = 0.55 + (477 − fs)/(120(0.9 + M/bd²)) ≤ 2.0
Clauses: 3.4.4.4 (K, K′, z, As); 3.5.1/3.5.2 (slabs, analysis outside tool); Table 3.25 (minimum steel); 3.12.6.1 (maximum 4%); 3.4.6 / Tables 3.9–3.10, eq 7–8 (span/depth); 3.12.11.2.7 (maximum clear spacing 3d or 750 mm).
© 2026 QP Academy. Original calculation software implementing BS 8110-1:1997 (+A1, A2, A3). BS 8110 is WITHDRAWN (superseded by BS EN 1992-1-1 and, in Singapore, SS EN 1992-1-1). For education and for checking legacy designs only — not for new design submissions.
Not covered: Slabs requiring compression steel (K > K′) — reported as FAIL, redesign; Two-way, flat, ribbed slabs; moment/shear analysis; shear and punching; crack-width calculation; distribution steel; fire; Cantilevers longer than 10 m
Version 0.1.0 Draft
EDUCATION PREVIEW — NOT YET INDEPENDENTLY CHECKED. Education preview: this calculator has not yet been independently checked by an engineer. Use for learning only — not for engineering use. Outputs are stamped and must not be used for engineering work.
Excel workbook
The workbook is available with the calculator once this version is released.
Exercises
Assessment in preparation.