Cellular Cement Composition Using Clay-Rich Aggregates

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Solution Overview

Problem

Conventional self-levelling screeds containing high percentages of clay and flint are unsuitable for construction due to low compressive strength, tendency to lift, and alkali-silica reactions, requiring costly and time-consuming purification processes, and existing cellular cement compositions do not effectively utilize these aggregates.

Innovation Solution

A cellular cement composition incorporating naturally occurring stone aggregates with high clay and flint content, treated with grinding and additives like aerating foaming agents, gel forming agents, and water-reducing agents, which are mixed with hydraulic binders and polymeric inerts to create a self-levelling screed with enhanced mechanical strength, acoustic insulation, and thermal conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If natural stone aggregates with high clay and flint content are used in cement composition, then material availability and cost are improved, but compressive strength deteriorates and surface stability worsens

Engineering Contradiction:
Improveavailability of aggregatesVSAvoidcompressive strength
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The patent converts the harmful effects of clay (low compressive strength, surface lifting) and flint (alkali-silica reactions) into beneficial properties by incorporating them into a cellular cement composition where their negative effects are neutralized by the cellular structure and chemical composition, while their availability and cost advantages are preserved

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

Solution Approach 2:

The patent changes the parameters of the cement composition by incorporating specific percentages of clay (5-20%) and flint (5-15%) along with cellular components and chemical additives that modify the chemical and physical properties to achieve adequate strength despite the presence of weak materials

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If natural stone aggregates with high clay content are used in cement composition, then material availability is improved, but surface stability deteriorates due to clay lifting

Engineering Contradiction:
Improveavailability of aggregatesVSAvoidsurface stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent converts the harmful surface-lifting property of clay into a stable cellular structure where clay particles are distributed within the cellular matrix, preventing surface accumulation and lifting while maintaining surface stability

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

3Quantity of substance

If flint is present in cement composition, then material availability is improved, but durability deteriorates due to alkali-silica reactions

Engineering Contradiction:
Improveavailability of aggregatesVSAvoiddurability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent converts the harmful alkali-silica reaction potential of flint into a controlled chemical environment where the reaction is suppressed by the cellular structure and chemical composition, allowing flint to be used without compromising durability

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

4Quantity of substance

If clay content in cement composition is increased, then material availability is improved, but pumpability deteriorates

Engineering Contradiction:
Improveavailability of aggregatesVSAvoidpumpability
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The patent changes the rheological parameters of the cement composition by incorporating cellular components and chemical additives that modify viscosity and flow characteristics, enabling pumpability despite high clay content

Inventive Principle:
Principle #35Parameter changes

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 enables the use of previously discarded aggregates, reducing costs and environmental impact, while providing a self-levelling screed with improved mechanical strength, acoustic insulation, thermal conductivity, and anti-seismic characteristics, eliminating the need for extensive purification and preventing surface crumbling and alkali-silica reactions.

Implementation Method 1

a cellular cement composition... with excellent quality of acoustic insulation and thermal conductivity

Methodology Applied
Scientific EffectFoam: Foam

Implementation Method 2

at least a gel forming agent

Methodology Applied
Scientific EffectGel: Gel

Implementation Method 3

at least a water reducing agent... conferring in this way the self-levelling nature of the cement composition

Methodology Applied
Scientific EffectViscosity reduction:

Implementation Method 4

Hydraulic binder; Stone aggregate... mixed to each other with mixing water

Methodology Applied
Scientific EffectHydration: Mineral Hydration

Data Source

PatentEP3922618B1Cellular cement composition, method for obtaining it, its use for realizing a self-levelling screed, and self-levelling screed realized
Publication Date: 2023.09.13 PELUSI CLAUDIO

AI summary

Cellular cement composition applicable in the in the building field with the function of self-levelling screed, comprising a dry, or naturally wet, mixture constituted by at least a stone aggregate, by at least a hydraulic binder, by possible polymeric inerts and mixing water, wherein said stone aggregate is constituted by sedimentary rock comprising the following component elements, calcarenite, argillite, calcite, flint, artificial conglomerate and opaque minerals, furthermore, such a stone aggregate, with respect to the total volume thereof, having a portion comprised between 35 - 40 % in volume of granules with size smaller than 0,063 mm, said stone aggregate being in a quantity comprised between 325 and 1430 % in weight with respect to the weight of the hydraulic binder, said cellular cement composition comprising also in addition a water-reducing agent, an aerating foaming agent, at least a least a gel forming agent. It is also provided a method for obtaining such a cement composition, its use for realizing a self-levelling screed, and the self-levelling screed realized.