Expansion Anchor Mortar Composition for Thin Borehole Bonding
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Solution Overview
Problem
Existing expansion anchor systems require high installation forces and often result in reduced strength and performance due to large borehole diameters and inadequate mortar distribution, especially when the expansion anchor is installed before the mortar.
Innovation Solution
A method involving a bolt with a tapered expansion region and an expansion sleeve, using a mortar with ≤72.5 wt.% inorganic filler, which is inserted into the borehole and then expanded radially to create a strong mechanical bond, allowing for convenient and uniform installation with reduced mechanical forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the borehole diameter is increased to facilitate anchor and mortar installation, then the ease of operation improves, but the strength and performance of the system is reduced
Solution Approach 1:
The patent changes the chemical composition parameters of the mortar by limiting inorganic filler to ≤72.5 wt.% and requiring ≥20 wt.% elastic polymer adhesive, creating a more flexible mortar that can effectively fill and bond in smaller boreholes while maintaining installation ease
Solution Approach 2:
The patent uses a composite mortar material combining organic polymer adhesive (≥20 wt.%) with inorganic filler (≤72.5 wt.%), creating a material that balances flexibility for installation with bonding strength for performance, eliminating the need for large boreholes
2Ease of operation
If the expansion anchor is installed before the mortar, then the ease of operation improves, but the uniformity of mortar distribution deteriorates
Solution Approach 1:
The patent applies preliminary action by filling the borehole with the flexible mortar composition before inserting the expansion anchor, allowing the mortar to be properly distributed and positioned ahead of time, ensuring uniform coverage when the anchor is subsequently installed
Solution Approach 2:
The patent modifies the mortar's rheological parameters through polymer content (≥20 wt.%) and filler content (≤72.5 wt.%), creating a composition that remains workable and distributable during anchor installation while ensuring uniform coverage and bonding
3Productivity
If the amount of mortar used is reduced, then the productivity improves, but the bonding strength deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the mortar by requiring ≥20 wt.% elastic polymer adhesive and limiting inorganic filler to ≤72.5 wt.%, creating a highly effective bonding material that achieves strong adhesion with minimal quantity, thus maintaining productivity while ensuring bonding strength
Solution Approach 2:
The patent applies local quality by concentrating the bonding function in the polymer-rich mortar composition, where the high polymer content (≥20 wt.%) provides enhanced adhesive properties that maximize bonding efficiency per unit volume, allowing reduced mortar quantities to achieve sufficient bonding strength
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method significantly reduces the effort required for installation, achieves a strong mechanical bond, and maintains high bonding strength, enabling efficient and uniform installation of expansion anchors, even with a thin borehole or anchor, thus improving the overall performance of the anchor system.
Implementation Method 1
The mortar is a chemical mortar which is cured by chemical reaction. Upon curing, the organic polymers are crosslinked and form a polymer matrix.
Implementation Method 2
The mortar comprises an inorganic filler which is dispersed in the polymer matrix after curing.
Implementation Method 3
applying a torque to withdraw the expansion anchor (1) a short distance out of the borehole, such that the expansion sleeve (6) is radially expanded
Data Source
Figure 1
AI summary
The invention relates to a method for installing an expansion anchor (1) in a borehole, wherein the expansion anchor (1) comprises a bolt (2) with an expansion region (3) at the frontal end (4) and a neck region (5), wherein the expansion region (3) adjoins the neck region (5) and tapers to the neck region (5), an expansion sleeve (6) at least partially surrounding the neck region (6), and a thread (7) for a nut (8) at the rear end (9), the method comprising the steps of a) filling into the borehole a mortar, which comprises an organic polymer adhesive and inorganic filler, b) inserting the expansion anchor (1) into the borehole with the frontal end (4) first, c) applying a torque to withdraw the expansion anchor (1) a short distance out of the borehole, such that the expansion sleeve (6) is radially expanded, and d) hardening and/or curing the mortar to obtain the installed expansion anchor (1), wherein the mortar comprises ≤ 72.5 wt.% inorganic filler, based on the total weight of the mortar. The invention also relates to a mounting system comprising a substrate having a borehole and an expansion anchor (1) installed in the borehole,