Structural Engineering & Statics
where the load goes
Concept

Splitting — where it appears

A tension acting across a compression that is spreading, which appears wherever a force is delivered to something wider than itself. It has no external load behind it, it is invisible to any equilibrium check on the member as a whole, and it is what cracks anchorage zones and concrete cover.

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

1200 kN214 kN of tiestruts at 20°0.5 huniform from here onGuyon: 0.25 P (1 − a/h) = 214 kN — the same number, from the same lever armbearing 20.0 N/mm² · once spread 5.7 N/mm²

The force that splits what it pushes on

A prestressing tendon delivers its whole force through a plate a fraction of the section deep. One depth further along the stress is uniform, and the spreading in between requires a transverse tension nobody applied — the force that splits end blocks, and the only number in the design that no equilibrium equation on the member can see.

internal-forces · anchorage zone 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.

PrestressReinforcementAnchorageAnchorage zoneBearing stressBondBurstingConcrete strengthCorrosionCoverCrack widthD region

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