Calcium Nitrate Setting Accelerator for Dry Mortar

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Solution Overview

Problem

Existing dry mortar blends face issues with clogging and odor emissions when using calcium nitrate as a setting accelerator, due to its high water content and particle size, which affects the mortar's setting time and durability, especially in blended cements and reinforced structures.

Innovation Solution

A dry mortar blend with a setting accelerator comprising anhydrous calcium nitrate powder or a salt complex of calcium and potassium nitrate, processed to have a water content between 0.1% and 20% and a particle size of 0.1mm to 1mm, preventing caking and odor release, and enhancing setting acceleration through exothermic dissolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If calcium nitrate is used as a setting accelerator in dry mortar blend, then setting acceleration is achieved, but clogging and odor emissions occur due to high water content and particle size

Engineering Contradiction:

Improvesetting accelerationVSAvoidclogging and odor emissions

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical parameters of calcium nitrate by reducing particle size to 0.63 mm or less and controlling water content to 0.1-20%, which eliminates clogging and odor issues while maintaining setting acceleration effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material formulations by combining calcium nitrate with specific cement types (CEM II/A-V, CEM III/A, CEM III/B, CEM III/C) and admixtures to achieve optimal setting acceleration while preventing harmful effects through the composite interaction of components

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If calcium chloride is used as a setting accelerator, then cost efficiency is improved, but metal corrosion occurs leading to expansion and cracking

Engineering Contradiction:

Improvecost efficiencyVSAvoidmetal corrosion

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces expensive calcium formate with more economical calcium nitrate, achieving cost efficiency similar to calcium chloride while avoiding the metal corrosion problem through the use of nitrate instead of chloride ions

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent introduces calcium nitrate as an intermediary substance that provides the desired setting acceleration effect without the harmful corrosion properties of calcium chloride, mediating between cost efficiency and structural integrity requirements

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of time

If carbonate is used as a setting accelerator, then setting time is reduced, but pH value decreases causing harm to embedded reinforcement

Engineering Contradiction:

Improvesetting timeVSAvoidpH reduction

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical parameter by using calcium nitrate instead of carbonate, achieving setting time reduction while maintaining appropriate pH levels through the nitrate ion's neutral chemical properties

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of rapid setting into a benefit by using calcium nitrate which provides both setting acceleration and pH stability, turning what could be a harmful rapid reaction into a controlled beneficial process

Inventive Principle:

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

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 solution ensures effective setting acceleration without clogging or odor issues, maintaining mortar paste performance comparable to conventional mortars, while being suitable for various cement types and reinforced structures.

Implementation Method 1

setting acceleration of the mortar paste being the mixture of the dry mortar blend with water occurs even better due to the exothermic effect of the dissolution of this anhydrous calcium nitrate powder in the remaining water

Methodology Applied

Scientific EffectExothermic dissolution: Exothermic Reaction

Data Source

PatentEP3066059B1Use of a setting accelerator for a dry mortar blend, process for producing such a setting accelerator and a dry mortar blend

Publication Date: 2017.08.23 YARA INTERNATIONAL ASA

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AI summary

The invention relates to a setting accelerator for a dry mortar blend, the setting accelerator being in the form of a powder comprising calcium nitrate and having a water content between 0.1% and 20%. The invention furthermore relates to a process for producing such a setting accelerator, wherein either prills and/or granules comprising calcium nitrate and a different nitrate salt are processed forming a powder comprising calcium nitrate and the different nitrate salt and having a water content of higher than 5% and lower than 20%, either an aqueous solution at least comprising dissolved calcium nitrate is spray dried at a temperature between 150°C and 250°C, forming a powder comprising at least calcium nitrate and having a water content between 0.1% and 20%, the powder serving as the setting accelerator. The invention also relates to a dry mortar blend comprising at least a cement, sand and a setting accelerator according to the invention and to a mortar paste comprising the dry mortar blend according to the invention which is mixed with water.