Resources

MASON Mechanical Anchors

All mechanical anchors for use in concrete works on the same basic principle:

1. Drill a specific sized hole

2. Clean the drilled hole

3. Insert the anchor into the pre-drilled hole

4. Expand the anchor via displacement or torque to be larger than the pre-drilled hole

5. The frictional force generated from the anchor and concrete will resist the pull-out force. As an anchor is loaded to its ultimate loading capacity, displacement of the mechanical anchor in relative to the base material will occur. The amount of displacement will be affected by the anchor pre-load, the design of the mechanical anchor and the base material. 

Installation

It is essential that all anchors are installed correctly as specified in the installation procedure to achieve the stated performance values.

1. Drilling

Appropriate tools & equipment must be used to meet the required drilling diameter and embedment depth.

2. Cleaning of the hole

The holes are required to be brushed and blown out to remove the maximum amount of dust and debris.

3. Installation of the anchor

The anchor must be installed in accordance to the technical specification.

4. Installation torque

Applying tightening torque in accordance to the technical specification sizes would ensure a clamping force that is greater than the stipulated working loads. The applied tightening torque must not exceed the installation torque as it will over stress both the anchor and the base material; which may result in the steel failure of the anchor.

Edge and Spacing distances

Mechanical expansion anchor transmit expansion forces by locally compressing the base material. The forces are exerted at the point of the expansion not over the total length of the fixing. The performance of the anchor is related to the projected area within the concrete cone. As the embedment depth increases, the concrete cone size will increase; thus, improving the performance of the anchor. There must be minimal influence between the based material edge distance and spacing distance with another anchor. Any reduction in the projected area will result in decrease in performance. Where there is a requirement to call for the reduction of spacing or edge distances, a reduction factor should be applied to the recommended load resistance of the anchor. 

Use of serrated or adequated washers for slotted holes

When fixing anchor bolts through slotted holes it is important to ensure that there is adequate surface contact between the washer and the fixture to guarantee positive clamping force. 

Base material

It is important to understand the difference in installing anchors into different base materials. The process and holding values will differ depending on the based material used. On-site testing should be arranged to verify and confirm the suitability and loading capacity of the selected anchor.

Load direction

During the selection of an appropriate anchor, all direction of loads applied must be taken into consideration.

Tensile pull-out loads, N: 

Pullout loads are applied along the axis of the fixing. Common examples are dead loads applied on ceiling applications or wind loads on anchor used to fix brackets on to vertical surfaces. Pullout resistance is influenced by the anchorage depth of drilled hole and tightening torque. 

Shear loads, V:

Shear loads are applied at right angles to the axis of a fixing and directly against the face of the load bearing structure. Shear resistance is influenced by the steel shear strength of the anchor material and the compressive strength of the load bearing structure.

Combined loads:

Combined loads are the combination of pullout and shear loads. If the angle of combined load is within 10 degrees of pure shear or pullout load, then the safe working load for the direction may be taken into consideration. Otherwise the applied combination loads should be resolved into its pullout and shear load.

Offset (stand-off) loads:

It is also known as ‘Lever Arm’ applications are applied at right angles on the fixing axis but are offset from the surface. There are two types as

(i) Clamped to the wall and

(ii) Filled with mortar layer (grouting layer) 

In all situation the deflection of the anchor bolt due to bending moment needs to be considered as well as the shear capacity of the bolt.

Mode of failure

The following mode of failure can occur when an anchor is loaded to its ultimate capacity:

a) Concrete cone failure

• Anchor is loaded to its ultimate tensile capacity
• Applied load is greater than the compessive strength of base material
• Anchors installed at a shallow embedment depth

b) Anchor pullout (Slippage) failure

• Incorrect installation or an anchor is loaded to its ultimate capacity

c) Disruption failure

• Incorrect base material dimensioning 
• Anchors installed close to an unsupported edge (free edge) 
• An anchor installed close to another anchor (less than recommended spacing)
• High expansion mechanism by the applied load

d) Splitting failure

• Insufficient base material dimensioning include the thickness and the width

e) Concrete pry-out failure

• Anchor is loaded to its ultimate shear capacity
• Applied load is greater than the compessive strength of base material
• Anchors installed at a shallow embedment depth

f)  Anchor material (steel) failure

• Insufficient anchor bolt material resistance
• Loads exceed steel yield strength

Corrosion resistance

MASON Mechanical Anchor comes with various types of plating, coating or materials so as to meet the required corrosion resistance. 

Quality assurance

MASON Mechanical Anchors are produced in accordance to the strict control of ISO 9001, ISO 9002 and the German TUV Certification. Our quality assurance processes require every product produced be inspected not only by the machinery operator but also by our quality assurance team.

Quick Selection Guide

i) Fastening Base Materials

Anchor Types	Fastening Base Materials
	*Solid Concrete	Lightweight Concrete	**AAC	**Hollow-Core Concrete	Solid Brick	Hollow Brick	**Gypsum Board
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ii) Coatings & Anchor Materials 

Anchor Types	Coatings & Anchor Materials
	Galvanised Carbon Steel	Yellow Zinc Chrome Carbon Steel	***Hot Dipped Galv. Carbon Steel	SUS 304 (A2)	SUS 316 (A4)
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	√ Zinc Alloy Body
	√			√ Nylon Plug	√ Nylon Plug
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* Non-cracked concrete compressive strength minimum C20/25 (Cylindrical test sample 20 N/mm²)  

** On site demo-installation and pullout testing may be required to verify the suitability of anchor and fastening base

*** Non-stock items. Please check for stock availability.