Ultralight Mineral Foam Stabilization via Calcium Silicate Control
Solution Overview
Problem
Existing methods for producing ultralight mineral foams face challenges in achieving stability and cost-effectiveness, as they often require complex mixtures of additives and result in foams that sag due to coalescence, Ostwald ripening, and hydrostatic pressure, limiting their density to around 100 kg/m³.
Innovation Solution
A process involving the preparation of an aqueous foam and a cement grout with specific ratios of water, cement, water-reducing agents, calcium salts, and silicate salts, which are then combined and shaped to set, allowing for the production of stable ultralight mineral foams with densities between 30 to 80 kg/m³ without the need for expensive or reactive cements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If conventional methods are used to produce ultralight mineral foams, then foam density is reduced, but foam stability deteriorates due to coalescence, Ostwald ripening, and hydrostatic pressure causing sagging
Solution Approach 1:
The invention changes the chemical parameters of the cement grout by controlling the water-to-cement ratio (W/C between 0.25 and 0.40) and the concentrations of calcium ions (0.03-0.97% by mass relative to cement) and silicate ions (0.04-1.67% by mass relative to cement). These parameter changes create a chemical environment that stabilizes the foam structure while maintaining ultralight density between 30-80 kg/m³, overcoming the conventional trade-off between density and stability.
Solution Approach 2:
The invention creates a composite system combining cement grout with specific chemical additives (calcium salts and silicate salts) and aqueous foam. This composite formulation achieves both ultralight density and high stability by synergistically combining the foam's lightness with the cement matrix's structural integrity and the chemical additives' stabilizing effects, eliminating the need for complex commercial foam stabilizers.
2Stability of the object's composition
If complex mixtures of additives are used to achieve foam stability, then foam stability improves, but manufacturing complexity and cost increase
Solution Approach 1:
The invention extracts and eliminates the need for complex commercial foam stabilizers and numerous additives from the conventional formulation. By using only cement, water, calcium salts, and silicate salts, the invention simplifies the material composition while maintaining foam stability, directly addressing the contradiction between stability and manufacturing complexity.
Solution Approach 2:
The invention replaces expensive, complex foam stabilizers with inexpensive, readily available materials (cement, water, calcium salts, silicate salts). These simple materials provide sufficient stability for the application without requiring costly additives or complex formulations, reducing both material cost and manufacturing complexity.
3Stability of the object's composition
If high reactivity cements are used to form stable foams, then foam stability improves, but production cost and difficulty increase
Solution Approach 1:
The invention changes the reactivity parameters by using ordinary Portland cement with controlled W/C ratio and specific calcium/silicate ion concentrations. This parameter optimization allows the cement to provide sufficient stability for ultralight foams without requiring high-reactivity cements, making the material easier to handle and more compatible with standard construction practices while maintaining foam stability.
Solution Approach 2:
The invention introduces calcium salts and silicate salts as intermediary substances that mediate between the cement and foam components. These intermediaries facilitate stable foam formation with ordinary cement by controlling the chemical environment, eliminating the need for high-reactivity cements and simplifying the manufacturing process.
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
This method produces stable, cost-effective ultralight mineral foams that do not sag when poured vertically, achieving densities between 30 to 80 kg/m³ and offering improved thermal insulation and fire resistance without the need for autoclave or heat treatment steps.
Implementation Method 1
These foam sagging problems can be due to coalescence phenomena, Ostwald ripening, hydrostatic pressure or drainage
Implementation Method 2
These foam sagging problems can be due to coalescence phenomena, Ostwald ripening, hydrostatic pressure or drainage
Implementation Method 3
Mineral foam refers to a material in the form of a foam. This material is lighter than traditional concrete because of the pores or empty spaces it contains. These pores or empty spaces are due to the presence of air in the mineral foam and can appear in the form of bubbles.
Implementation Method 4
The presence of air in the mineral foam and can appear in the form of bubbles
Implementation Method 5
A cement C is a hydraulic binder comprising a proportion at least equal to 50% by mass of calcium oxide (CaO) and silicon dioxide (SiO 2)
Data Source
AI summary
The invention relates to an inorganic foam manufacture method including the following steps: (i) separately preparing an aqueous foam and a cement slurry, the cement slurry containing water E, a cement C, a water-reducing agent, a water-soluble calcium salt, and a water-soluble silicate salt, the calcium/silicon molar ratio being of from 0.7 to 1.7 and the weight ratio E/C being of from 0.25 to 0.40, it being understood that the calcium ion concentration is of from 0.03 to 0.97%, the percentage being expressed as wt.% relative to the cement weight, and that the silicate ion concentration is of from 0.04 to 1.67%, the percentage being expressed as wt.% relative to the cement weight; (ii) placing the obtained cement slurry in contact with the aqueous foam so as to obtain a foamed cement slurry; and (iii) shaping the foamed cement slurry obtained in step (ii) and letting said foamed cement slurry set.