Key

Definition

A key is a slot formed into a concrete surface to interlock with a subsequent pour of concrete; a slot at the edge of a precast member into which grout will be poured to lock it to an adjacent member.

Purpose

The purpose of a key is to create a mechanical interlock between concrete pours or precast members, enhancing the bond and structural integrity of the concrete elements. It prevents movement and ensures a cohesive connection between sections.

Examples of Use

1. Construction Joints: Keys are used in construction joints to connect new concrete pours to existing ones securely.
2. Precast Concrete: In precast construction, keys are formed at the edges of panels to be filled with grout, locking them together.
3. Retaining Walls: Keys are incorporated into retaining walls to prevent lateral movement and enhance stability.

Related Terms

• Tongue and Groove: A method of fitting similar objects together, edge to edge, used mainly with wood and plastic.
• Interlocking: A method of connecting materials together to prevent movement and increase strength.
• Grout: A fluid form of concrete used to fill gaps and provide structural reinforcement.

Notes

Properly designed and installed keys are crucial for the structural integrity of concrete constructions. They must be precisely formed and filled with suitable materials to function effectively.