Two-Component Aluminous Cement Mortar for Stable Chemical Anchoring

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Solution Overview

Problem

Existing two-component mortar systems based on aluminous cement suffer from instability during storage, toxicity, and inadequate mechanical performance under elevated temperatures, particularly when used for chemical fastening of anchoring means in mineral surfaces.

Innovation Solution

A two-component mortar system comprising a curable aqueous-phase aluminous cement component A with a blocking agent (phosphoric acid) and an initiator component B with a retarder (citric and tartaric acid) and mineral fillers, ensuring stable storage and rapid curing with controlled set-time, even under elevated temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If boric acid or salts thereof are used as retarder in aluminous cement aqueous suspensions, then the setting time can be controlled, but the system becomes unstable during storage and the retarder is toxic and ecotoxic

Engineering Contradiction:
Improvesetting time controlVSAvoidstorage stability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent extracts boric acid from the system and replaces it with non-toxic organic acids (citric acid, tartaric acid, lactic acid, salicylic acid, or gluconic acid) that perform the same retardation function without the toxicity and storage instability problems. This substitution resolves the contradiction by removing the harmful substance while maintaining the desired setting time control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical parameter of the retarder from inorganic boric acid to organic acids with different molecular structures and properties. This parameter change maintains the retardation mechanism (inhibiting calcium aluminate hydration) while eliminating the toxicity and storage stability issues associated with boric acid.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If organic systems based on free-radically polymerizable resins are used for fast curing, then the curing speed is improved, but the system becomes polluting, expensive, potentially hazardous and toxic

Engineering Contradiction:
Improvecuring speedVSAvoidtoxicity and pollution
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the traditionally harmful organic resin-based fast-curing systems into beneficial inorganic aluminous cement systems. By using inorganic chemistry (calcium aluminate hydration) instead of organic polymerization, the system achieves rapid curing without the associated toxicity, pollution, and safety hazards, while also providing superior thermal and chemical resistance.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent replaces expensive organic resins with more economical inorganic aluminous cement materials. The inorganic system provides comparable or superior performance at lower cost without the environmental and health burdens of organic alternatives.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Strength

If aluminous cement systems are used for chemical anchoring, then the mechanical performance and resistance to bases and sulfates is improved, but the stability during storage is insufficient

Engineering Contradiction:
Improvemechanical performanceVSAvoidstorage stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent introduces organic acid retarders as intermediary substances that mediate between the aluminous cement and water, controlling the hydration reaction rate. These intermediaries prevent premature setting during storage by blocking the activation of calcium aluminate, yet allow controlled curing when needed, thereby resolving the storage stability issue while maintaining mechanical performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 system provides a ready-for-use, eco-friendly solution with excellent mechanical performance and extended shelf life, maintaining bond strength at elevated temperatures, suitable for anchoring metal elements in mineral surfaces.

Implementation Method 1

component A further comprising at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid and phosphonic acids

Methodology Applied
Scientific EffectChemical inhibition:

Implementation Method 2

an initiator component B in aqueous-phase for initiating the curing process

Methodology Applied
Scientific EffectChemical reaction:

Implementation Method 3

component B comprising an initiator, at least one retarder, at least one mineral filler and water, wherein the at least one retarder is selected from the group consisting of citric acid, tartaric acid, lactic acid, salicylic acid, gluconic acid and mixtures thereof

Methodology Applied
Scientific EffectChemical retardation:

Implementation Method 4

A two-component mortar system for chemical fastening of anchoring means in mineral surfaces

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 5

excellent mechanical performance and extended shelf life, maintaining bond strength at elevated temperatures

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 6

component A further comprising at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid and phosphonic acids, at least one plasticizer and water

Methodology Applied
Scientific EffectViscosity reduction:

Data Source

PatentUS20250243117A1Two-component mortar system based on aluminous cement and use thereof
Publication Date: 2025.07.31 HILTI AG

AI summary

A multi-component mortar system contains a curable aqueous-phase aluminous cement component A and an initiator component B in aqueous-phase for initiating the curing process. Component A further contains at least one plasticizer, water, and at least one blocking agent selected from phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acids. Component B contains an initiator, at least one retarder, at least one mineral filler, and water. A multi-component system is useful, which is ready-for-use, for chemical fastening of anchoring means, preferably of metal elements, in mineral surfaces, such as structures made of brickwork, concrete, pervious concrete or natural stone as well as its use for chemical fastening of anchoring means.