User Guide

However, if the interpretation of on-site testing results is not done correctly,

this assessment could compromise the stability of the structure, put human life at risk

and/or lead to considerable economic consequences.

The statements above are explained and justified on the following pages.

GENERAL BACKGROUND

Hilti anchor and post-installed rebar systems carrying an approval, installed

according to the manufacturer’s installation instructions and in base materials within

the scope of the approval do not require on-site testing for performance verification.

Generally speaking, you will encounter just three situations when on-site testing

should be performed:

(a) To determine the design resistance in a similar but not identical material as

given in the related approval (destructive or non-destructive tests)

(b) To validate the quality of installation of anchors used on the job site (non-

destructive tests)

distances, rebar/rod diameter etc. different to those values reported in the

related approval

Non-destructive loading (proof loading) is done by applying tension loads. The

load level is selected sufficiently high to provide assurance of correct installation or to

determine targeted design resistance values but not so high as to result in damage

(e.g. in the form of yielding or permanent slip) to a correctly installed anchor. Proof

loads should be maintained long enough to enable a determination of no anchor or

rebar movement. Given this objective, it should be clear that proof loads are set as a

percentage of the tested tension capacity of the anchor or rebar, not the design

tension load.

Note that, depending on the embedment to diameter ratio and the steel grade, this

load might or might not subject the anchor to yield level stresses. Where lower yield

steels are used, it should be verified that the proof loads do not exceed 80% of the

nominal yield stress of the steel anchor components.

If proof load is used to verify proper installation, proof loading equipment may have

load reactions close to the anchor but with sufficient clearance so any movement

would be visible. If proof load is used to determine design resistance values, proof