Use of carrageenan as a viscosity-modifying admixture in a flowable cementitious suspensions
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Solution Overview
Problem
Flowable concretes are sensitive to bleeding and segregation, and existing viscosity-modifying admixtures (VMAs) can increase yield stress, inhibit self-consolidating nature, or trap air bubbles, while being expensive and requiring complex fermentation processes.
Innovation Solution
Incorporating carrageenan as a viscosity-modifying admixture in flowable cementitious suspensions to enhance stability and reduce segregation, using algae-derived polysaccharides that offer effective rheological properties without increasing yield stress and at a lower cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional viscosity-modifying admixtures are used to improve stability and reduce segregation, then bleeding and segregation are reduced, but yield stress increases and self-consolidating properties are inhibited
Solution Approach 1:
The patent changes the chemical composition parameters by using carrageenan (a natural polysaccharide) instead of conventional synthetic VMAs, and by optimizing the dosage to 0.01-0.5% by weight. This parameter change allows achieving stability improvement without excessive yield stress increase, as carrageenan provides viscosity modification through different mechanisms that preserve flowability.
Solution Approach 2:
The patent creates a composite admixture system by combining carrageenan with other concrete components in specific proportions. The carrageenan integrates with the cement matrix and aggregates to provide enhanced stability while maintaining the self-consolidating characteristics through its unique rheological properties.
2Stability of the object's composition
If conventional viscosity-modifying admixtures are used to reduce segregation, then homogeneity is improved, but air bubbles are trapped and manufacturing complexity increases
Solution Approach 1:
The patent uses carrageenan, a natural polysaccharide derived from red algae, which decomposes easily in the concrete matrix without forming persistent harmful structures. This biodegradable approach eliminates the need for complex removal processes and avoids long-term issues with air bubble entrapment, while providing sufficient homogeneity improvement during the concrete's service life.
3Stability of the object's composition
If expensive viscosity-modifying admixtures are used to enhance stability, then segregation is reduced, but cost increases and production complexity increases
Solution Approach 1:
The patent replaces expensive synthetic viscosity-modifying admixtures with carrageenan, a natural polysaccharide that can be produced at lower cost through agricultural byproducts from red algae harvesting. The carrageenan is introduced at optimized dosages (0.01-0.5% by weight) that provide effective stability enhancement without requiring costly formulation processes or specialized production equipment.
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
Carrageenan improves the stability and homogeneity of flowable cementitious materials by reducing segregation and bleeding, maintaining self-consolidating properties, and providing cost-effective rheological enhancement.
Implementation Method 1
carrageenan as a viscosity-modifying admixture in flowable cementitious suspensions
Implementation Method 2
crosslinking between chains due to the presence of potassium ions (K+)
Implementation Method 3
The mode of action of carrageenan is based on the absorption of free water in the matrix
Implementation Method 4
Carrageenan acts with the K+ ions, present in cementitious materials, to stabilize the junction areas in the brittle gel
Data Source
AI summary
There is provided the use of carrageenan as a viscosity-modifying admixture in a flowable cementitious suspension; a viscosity-modifying admixture for a flowable cementitious suspension, the viscosity-modifying admixture comprising carrageenan; a method of modifying the viscosity of a flowable cementitious suspension, the method comprising adding carrageenan as a viscosity-modifying admixture to the flowable cementitious suspension. There is also provided a dry cementitious composition comprising carrageenan as a viscosity-modifying admixture and a flowable cementitious suspension comprising carrageenan as a viscosity-modifying admixture. The flowable cementitious suspension typically comprises the dry cementitious composition as well as water. The flowable cementitious suspension can be a self-leveling flowable cementitious suspension, such as grout or mortar for self-leveling flooring, crack injection, or and anchorage sealing, or a self-consolidating flowable cementitious suspension, such as a flowable concrete.