Information on the installation of anchor fastening - DIBt · Information on installation of anchors 2010 Page 4 of 12 2 Planning specifications for the installation Anchor systems

Information on the installation of anchor fastening

October 2010

Information on installation of anchors 2010 Page 2 of 12

Table of Contents

Foreword 3 1 General 3 2 Planning specifications for the installation 4 3 Installation instructions 5

3.1 Installation instructions for anchors 5 3.2 Additional installation conditions 6

4 Competence requirements for installers of anchors 7 4.1 Basic knowledge (fundamental competence requirements for all types of anchors) 7 4.2 Anchor-specific technical knowledge 8

5 Anchor training courses and training provisions 12


Foreword

According to the general requirements of the Landesbauordnungen ('Building Regulations of the Land') construction works shall be erected and arranged such that they will not be a threat to public safety and order; for that purpose only construction products and types of construction may be used which fulfill the legal requirements and are fit for their intended use.

The verification of applicability for anchorages and fasteners (e.g. metal anchors and bonded anchors, plastic anchors, powder actuated fasteners) in concrete and masonry structures normally occurs via an allgemeine bauaufsichtliche Zulassung ('national technical approval') and/or a European technical approval (ETA).

The approvals show the characteristic values of the anchors which are determined on the basis of extensive uniform test requirements. Furthermore they contain assumptions concerning manufacture, design and installation of the product as precondition for the use of these characteristic values.

The load-bearing capacity and the reliability of anchorages are affected to a large extent by the way on how the anchorages are planned and installed. The installation instructions by the manufacturer as well as the construction drawings and their transposition on site are, therefore, of fundamental importance for the serviceability of an anchor for an intended use.

Compliance with and transposition of the installation instructions and the construction drawings can only be ensured on site by the appropriate competence of the installers. The competence shall be proven.

This document provides adequate explanations for designers and installers. It compiles the competence requirements for installers and provides an overview of training opportunities. A prerequisite is that selection, planning and design will be carried out solely by the designer.

1 General

In the allgemeinen bauaufsichtlichen Zulassungen ('national technical approvals') and the European technical approvals special conditions are defined for planning, design and installation of anchorages. In general these special conditions are to be adhered to and followed, as they are the basis for the safety concept set out for the planning and calculation of the anchorage.

The following paragraph 2 contains the specifications for the installation resulting from the planning and design of the anchorage which the installer needs on site and which have to be included in the construction drawings.

As to the installation of anchors the special conditions of the approvals include specifications for the base material, the installation conditions; they also give full particulars on the installation operations by means of precise instructions (see section 3).

The specific conditions require that the serviceability of the anchorage can only be assumed if the installation of the anchors is performed by trained personnel under the responsibility of the construction supervisor. The necessary competence of installers and possible training provisions are introduced in sections 4 and 5. If these boundary conditions are kept it can be presumed that trained personnel is involved.


2 Planning specifications for the installation

Anchor systems must be planned and designed. Selection, planning and design of an anchor system are not the task for installers. Deviations from the specifications of the construction drawings must not be carried out by the installer arbitrarily.

At least the following details shall be given in the construction drawings:

- Type of anchor, dimension, material variant, effective length, for anchors with variable anchorage depth also anchorage depth and depth of drilled hole,

- drilling method,

- base material, designation, e.g. C20/25,

- geometrical arrangement of the anchorage with distances to edges and further anchors as well as thickness of the member,

- if need be, installation conditions for certain anchors (e.g. special cleaning of the drilled hole in case of chemical anchor systems),

- geometric dimensions of the fixture including position and diameter of the clearance holes,

- thickness and type of the non-loadbearing layers considered in the planning,

- subsequent corrosion protection for plastic anchors, if required in the approval.

Example drawing:

Anchor "TYPE XXX M10x60/20 A4" made of stainless steel

Base material: cracked concrete, normal reinforcement, concrete strength class C20/25

Thickness of the anchor plate: 10 mm

- drilling diameter in the anchor plate: 10.5-12 mm

- Drilling method: hammer drilling

- Minimum anchorage depth: 60 mm

- Non-load-bearing layer: render ≤ 10 mm


3 Installation instructions

Installation instructions for anchorages differ from product to product. Therefore, their compliance for the correct installation of the respective product is mandatory. Besides, before and during the installation on site additional conditions going beyond the product-specific installation instructions shall be taken into account.

The installation of the anchors is explained in detail in the installation instructions which are included in each of the approvals and are normally made available by the manufacturers in a shorter form as installation instruction. The installation instruction for the anchorages shall be complied with. The installation instructions which shall be made available by the manufacturer shall be observed. They shall be given on the packaging and/or a instruction leaflet, graphically preferred, completely and understandingly.

3.1 Installation instructions for anchors

The installation instructions for anchors should normally include information on the following:

Fastening system, components

Environmental conditions

Base material, classification

Drilling method, drill hole diameter, drill hole depth

Cleaning of the drill hole, methods, auxiliaries required (e.g. brush, brush diameter, blow-off devices)

Placing the anchor into the drill hole

Installation tool, setting tool

Internal thread sleeve: minimum screwing depth required

Clearance hole in the fixture

Torque moment when anchoring

Reception for screw driving tool, e.g. torx, wrench size

Clamping width, i.e. thickness of the fixture

Additional installation instructions for mechanical metal anchors and plastic anchors

Additional installation instructions for chemical anchors

Processing temperature for plastic anchors Setting of the sieve sleeve, if masonry

Information on dangerous substances, precautionary measures to be taken

Expiry date, storage temperature of the mortar

Processing temperature of the mortar and the system

Setting tools (pressure grouting equipment, mixer included)

Mixing, inserting the mortar

Curing time


3.2 Additional installation conditions

In addition to the installation instructions the following additional conditions shall be observed on site by the installer:

- The base material is to be checked. It needs to comply with the information in the planning documents. In case of visible damages (e.g. cracks, spallings, voids in the area of the anchorage) the designer and/or the construction supervisor shall be called in.

Concrete: General condition, moisture, cracks, blowholes, joints, spallings, etc. are to be checked. The concrete compressive strength has to be within the concrete compressive strengths stated in the approval (normally task of the planner).

Reinforcing steel, mounting parts: Position of the drill hole with regard to the distance to untensioned and/or prestressed reinforcement as well as other mounting parts such as pipes, cable is to be checked.

Masonry: Joint mortar, bulk density, compressive strength, hole pattern, web thicknesses, spallings are to be checked. The execution of the anchorage is permitted only in the bricks specified by the designer.

- The general accessibility for the installation of anchors has to be ensured.

- The bore holes are to be drilled perpendicular to the surface of the base material. Deviations to the vertical of up to 5° at the most are permitted.

- Unless otherwise stated in the approvals, hard metal hammer-drills according to ISO standards or applicable national standards shall be used. Numerous drill bits exhibit marking showing that the requirements of the standard are fulfilled.

- All special drill bits required according to the installation instructions of the manufacturer (e.g. stop drills or diamond core drill bits) have to comply with the specifications of the manufacturer. This is to be confirmed by the factory production control of the drill bits.

- The drill holes shall always be cleaned from drilling dust. The special instructions for cleaning the drill hole for chemical anchors shall be respected. Contaminants or ingress of water into drill holes shall be excluded by appropriate measures.

- The anchors shall be installed such that the anchorage depth laid down in the planning documents will be adhered to. Edge distance and spacing shall be kept according to the values specified; minus tolerances are not permissible.

- When drilling holes care must be taken that reinforcing bars in the vicinity of the drill hole will not be damaged. In the absence of other regulations it is recommended that the clear distance between the side of the drill hole and the outside of prestressed reinforcement amounts to at least 50 mm; for determining the position of the reinforcement in the construction part appropriate devices (e.g. reinforcement detectors) are to be used.

- Normally aborted holes shall be sealed completely with a low-shrink, high-strength mortar. A aborted hole shall also be deemed to exist in case the anchor is removed. In case of a aborted hole with a depth of ≥ hef / 4 the anchor may be set in the center distance equal to three times the drill hole diameter of a aborted hole. In case of a aborted hole with a depth of < hef / 4 the anchor may be set in the center distance equal to the simple drill hole diameter of the aborted hole. Prestressing and/or a load of the anchor after sealing the aborted hole with high-strength mortar is permissible at the earliest if the strength of the mortar corresponds to at least the concrete strength. Should the strength development of mortar not be known, then the anchor may be prestressed and/or loaded after 24 hours at the earliest, or if using approved injection mortar after the curing time specified.


- For anchors which are to be exposed to temperatures below 0°C measures shall be taken in order to prevent an ingress of water into the drill hole and a subsequent local crack formation in the concrete due to freezing pressure.

4 Competence requirements for installers of anchors

The responsibility for the performance of the correct installation of anchors rests with the executing company. The executing company shall employ appropriately trained personnel for the installation of anchorages. The personnel has to be able to read and understand the installation instructions and transpose them when installing.

The personnel should at least have the following competences in order to be classified as trained personnel. In this connection, the technical backgrounds and the consequences of a deviant behaviour are to be understood for the fields of competences stated. The competences shall be gained and proven in theory and practice by corresponding courses of training or training measures. The possible courses of training stated in section 5 are intended to serve that purpose.

4.1 Basic knowledge (fundamental competence requirements for all types of anchors)

Basic understanding as to the modes of action and particularities of the anchorage systems utilized and effects or consequences of deviations with the installation on the load bearing behaviour.

Comprehension has to be passed on for the following points which could have an effect on the load bearing behaviour:

- Installation-relevant provisions in the approval shall be respected.

- Trade name of the anchor as well as type, size and quality of material have to comply with the information in the approval and structural analysis. The anchors concerning type, size and quality of material, specified by the planner are to be used. A deviation without consent of the planner is not authorized.

- Installation only as delivered by the manufacturer, without replacing the individual parts.

- Drills of suitable diameter and tolerances according to the PGM benchmark shall be used.

- If need be, stop drills or other special tools shall be utilized (more details are given in the installation instructions or the approval).

- Significance of the cleaning of the drill hole and its consequences for the load bearing behaviour of the anchorage systems.

- Function of the cleaning brush and its possibilities to exercise control (e.g. brush gauge).

- Aborted holes could have a negative effect on the load bearing behaviour. For more information on aborted holes see installation instructions or approval.

- Non-loadbearing intermediate layers could have a negative effect on the load bearing behaviour. Fixtures are to be fixed directly on the base material without intermediate layers. Consulting the planner is required, if the non-loadbearing layer is thicker than shown in the construction drawing for the installation.

- Minimum distance of the anchor to the edge of the member shall be observed. Anchors shall not be set in construction joints.

- Different types of installation shall be observed (e.g. pre-positioned installation, in-place installation, stand-off installation).

- Various drilling methods shall be observed.


- Requirements concerning fix and maximum torque moment shall be observed.

- Requirements concerning screwing depth on anchors with internal thread shall be adhered to.

- Difference between monolithically manufactured concrete elements and/or manufacture with semi-finished products (e.g. "Filigrandecken") shall be observed.

- In case of deviations and distinctive features when installing, the construction supervisor has to be informed.

4.2 Anchor-specific technical knowledge

Comprehension has to be passed on for the following anchor-specific points:

Bolt anchors / sleeve anchors (torque-controlled)

Mechanism

For installing torque wrench shall be used and torque moment shall be observed (for more detailed information see installation instructions or approval).

Undercut anchors

Mechanism

The mechanism of the undercut anchor will be ensured by the reliable and verifiable making of the undercut.

If necessary, a special drilling and setting tool shall be used (for more detailed information see installation instructions).

Concrete screws / Anchor screws

Mechanism

Concrete screws and drill holes can only be used repeatedly if this is explicitly permitted in the approval.

For the installation appropriate tools and machines according to the approval or installation instruction shall be used. If necessary, tangential impact screwdrivers with suitable power shall be used (for more detailed information see installation instruction).

No easy continued turning of the concrete screws after setting.

Drop-in anchor (deformation-controlled)

Mechanism

If necessary, a setting tool shall be used (for more detailed information see installation instructions).

The drop-in anchor shall be hammered down completely (countersink expansions parts, markings to be observed).

Installation criteria (e.g. displacement criteria) of the approval or installation instructions need to be respected.

The correct screw length for fixing the fixture shall be determined considering the screwing


depth required.


Bonded anchors in general

Fastening system, components, observance of the information on dangerous substances.

The storage conditions for mortar compound shall be observed.

The mortar's date of expiry shall be observed; mortar where the expiry date has elapsed shall be disposed of according to the installation instructions.

Moisture in the concrete member and/or water in the drill hole.

Steel elements according to approval and/or manufacturer's recommendation shall be used only. When using customary standard parts, a 3.1 test certificate according to the corresponding standard must be available without fail.

Anchor rod with planned anchorage depth shall be used (marking and/or information by the planner shall be observed). Note that there are systems with variable anchorage depth.

Anchor rod shall be inserted completely (marking shall be observed).

When mounting overhead the measures stated in the approval shall be observed for this application (for more detailed information see installation instructions).

After the installation of the anchor rod the mortar has to emerge on the surface and the annular gap has to be filled completely.

Processing temperatures and cure times shall be observed (for more detailed information see installation instructions).

Even smaller loads and/or aligning the anchor is not admissible within the cure time.

Cartridge systems Capsule systems

The pressure grouting tool belonging to the bonded anchor system as well as the static mixer including blending spirals belonging to the cartridge shall be used for the injection process according to the installation instructions.

Attention shall be paid to an even staining (thorough mixing) of the emerging injection adhesive.

The flow of the mortar shall be discarded in accordance with the information in the approval.

The injection starts at the toe of the drill hole and shall be carried out bubble-free.

In case of assembling in perforated bricks a perforated sleeve shall be applied according to plan and approval.

For setting the anchor rod, drill hammer/percussion drilling machine with lash adjustor shall be used in order to ensure complete destruction and thorough mixing of the capsule and/or the foil capsule.


Plastic anchors

Mechanism.

Processing temperature shall be observed.

Anchors are considered to be set according to the rules, if, after the complete turning in of the screw, neither a rotation of the anchor sleeve nor an easy continued rotation of the screw will be possible.

The anchor must not be set into the drill hole by force, buckling of the anchor or cracks are to be avoided.

The special screws of suitable length and diameter delivered together with the anchor sleeve shall be used (for more detailed information see installation instructions).

Anchors for external thermal insulation composite systems

All setting regulations by the manufacturers of the anchors and the systems have to be observed.

Plugging shall always be done through the adhesive.

When determining the anchor length and the drilling depth, thickness of the adhesive, old rendering and non-loadbearing substrates shall be taken into account.

Number of anchors per m2 shall be observed. At the same time peripheral zones and, where applicable, height of the building and wind loads shall be considered.

The scheme for setting anchors shall be observed.

Screw anchors must not be driven in.

The anchor shaft must not be damaged during setting.

Anchors which were not correctly set have to be removed.

The counterbore depth and/or the depth of engagement shall be selected according to manufacturer's data, taking the insulating material into account.


5 Anchor training courses and training provisions

The responsibility for the competence of the anchor installers rests with the executing companies. At the same time it is also the executing company's responsibility as to which way will be chosen to ensure the competence of its installers. Internal or external seminars, briefing as well as a personal training course of the installer are conceivable. The decisive factor is the competence achieved and not the way how it had been done. Competence does not depend on a brand.

If specific requirements have to be met by the company and the personnel then these regulations are decisive. This, for example, applies to post-installed rebar connections, where specific requirements have to be met by the certification of the installers and the executing company.

In all other cases the diverse training courses offered can be chosen from various organizations. Basis for the training course for anchor installers is the communication of the requirements of competence stated in section 4.

When selecting the training course for anchors efforts must be made to ensure that the main focus is also placed at least on the application for the later installation of anchors.

The examples compiled below are organizations and/or forms of organization in the field of training courses for anchor installers:

- Vocational schools (e.g. training to become façade installer, metalworker)

- Training by branch associations (e.g. chambers of crafts, guilds, master schools)

- Internal training (firms for installation of anchors)

- Training in competence centers

- Training in craftsman centers

- Training by external bodies (e.g. universities, academies, engineering offices)

- Training by the manufacturer

- Training by sales partners.

Documents

Information on the installation of anchor fastening - DIBt · Information on installation of anchors 2010 Page 4 of 12 2 Planning specifications for the installation Anchor systems