Structural Engineering & Statics
where the load goes
Concept

Tensile strength — where it appears

The stress at which a material parts in tension, which for concrete is a tenth of its compressive strength and the smallest number in any reinforced calculation. It is deliberately ignored in strength design and it decides cracking, splitting and durability, which are the limits that arrive first.

Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.

01020304050050100150200250mid-span deflection (mm)moment (kNm)uncrackedthe memberfully crackedM_cr = 47 kNm34.2 mm at service, span over 234

Stiffer than its cracked section says

At a crack the concrete below the neutral axis has gone and the steel carries the tension alone. Between the cracks it has not gone — bond drags it back into tension, the steel strain drops, and the curvature averaged over a length of beam is neither section's.

deflection · tension stiffening 204060800102030405060cover (mm)years to a split coverinitiation ∝ c²and propagation35 mm: 9.1 yr70 mm: 36.2 yrthe cover splits at a section loss of 0.21%

The load that comes from inside

Every action in this collection has been applied from outside — a weight, a pressure, a movement, a temperature. Corrosion is not applied at all, and the reason it belongs to statics rather than to durability is that what does the damage is a load: rust occupies three times the volume of the steel it came from, and the only place to make room is by pushing the cover apart.

materials · corrosion

Named alongside it

The objects these essays reach for when they reach for this one.

BondReinforcementAnchorageCorrosionCoverCrack widthCracked sectionCracking momentCreepCurvatureDeflectionDiffusion

All concepts