Useful stuff · CIRIA C766 decision routes
Restrained deformation, creep and shrinkage: which check do I do?
Routes derived from CIRIA C766 Control of cracking caused by restrained deformation in concrete, to BS EN 1992 with the UK NA. Entry is by element; the element resolves the restraint type, and the restraint type resolves the check. Pick an element below to walk the ten stages, or jump to the printable matrix.
Step 1 — what are you designing?
The route — ten stages resolved for this element
Inputs to gather for this route
Designer owns
Allowable crack widths, restraint assumptions, pour sizes and casting sequence, reinforcement, and the design assumptions stated in the specification (C766 proforma Table 4.1).
Contractor owns
Mix design and cement type or content, placing temperature, formwork type, striking and curing times, and any additional measures such as cooling or insulation. C766 §1.6 makes this a joint responsibility — if measured values differ from the assumptions, the limits may be revised.
The six distinctions people trip on
CIRIA C766 · BS EN 1992 with UK NA
Printable matrix — all sixty nodes
Ten stages down, six elements across. Print (A3 landscape) for a pin-up sheet.
Kc1 = 0.65 early age · Kc2 = 0.50 long term
T2 = 20°C summer cast, 10°C winter cast
T2 = 20°C summer cast, 10°C winter cast