Concrete Admixture Defoamer Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing concrete admixtures often introduce unwanted air, leading to reduced strength and durability, and are unpredictable when combined with air entraining agents, causing fluctuations in air content during transport and placement.
Innovation Solution
An aqueous composition comprising an anionic polymer, a water-insoluble defoamer, and a polysaccharide, which stabilizes the defoamer and ensures compatibility with air entraining agents, maintaining a consistent air content in construction materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If water-insoluble defoamers are added to admixtures to reduce air content, then air content is reduced, but the defoamer separates from the aqueous solution and forms a layer on top
Solution Approach 1:
The patent introduces water-soluble polymers (such as polyacrylic acid, polyacrylamide, or their copolymers) as intermediary substances that act as solubilizing agents. These polymers form soluble complexes with the water-insoluble defoamer, enabling the defoamer to remain dissolved in the aqueous admixture solution without separating or forming layers, thus maintaining solution stability while preserving defoaming functionality.
Solution Approach 2:
The patent creates a composite admixture system combining water-insoluble defoamers with water-soluble polymers. This composite formulation allows the defoamer to maintain solubility through polymer association, achieving both effective air reduction and solution stability. The composite structure prevents phase separation while maintaining the defoaming active components in the aqueous phase.
2Object-generated harmful factors
If defoamers are added to admixtures to reduce air content, then air content is reduced, but the combination with air entraining agents results in unpredictable air content fluctuations
Solution Approach 1:
The water-soluble polymer acts as a mediating substance that creates a stable molecular environment for both defoamers and air entraining agents. By forming soluble complexes with defoamers, the polymer prevents harmful interactions between defoamers and air entraining agents, allowing both components to function predictably together and maintain consistent air content throughout the concrete mixture.
Solution Approach 2:
The patent modifies the chemical and physical parameters of the admixture system by introducing water-soluble polymers that change the solubility and interaction characteristics of defoamers. This parameter change enables predictable behavior when defoamers are combined with air entraining agents, as the polymer creates a stable molecular environment that prevents unpredictable fluctuations in air content.
3Object-generated harmful factors
If the amount of defoamer is increased to prevent high air content, then air content is reduced, but the defoamer separates more readily from the aqueous solution
Solution Approach 1:
The water-soluble polymer serves as a mediating agent that enables higher concentrations of water-insoluble defoamers to remain dissolved in the aqueous solution. The polymer forms soluble complexes with the defoamer, allowing increased defoamer loading without causing phase separation or layer formation, thus maintaining solution stability even at higher defoamer concentrations.
Solution Approach 2:
The patent develops a composite admixture system where water-soluble polymers are combined with water-insoluble defoamers in optimized ratios. This composite formulation allows increased defoamer content while maintaining solution stability through the stabilizing effect of the polymer, preventing separation even when defoamer concentration is elevated.
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 composition prevents undesired air entrainment, providing a stable and predictable air content for up to 60 minutes, ensuring high-quality concrete or mortar that maintains quality during transport and placement.
Implementation Method 1
The addition of a polysaccharide to the aqueous composition comprising an anionic polymer and a water insoluble liquid defoamer, surprisingly gives storage stable compositions
Implementation Method 2
Defoamers are mostly hydrophobic substances based on silicon or mineral oils, phosphate esters or polypropylene glycol-derivatives
Implementation Method 3
EP 1 242 330 describes the use of solubilizing agents admixed with water insoluble defoamers and dispersants as admixture for cementitious compositions
Data Source
AI summary
A defoamed aqueous composition including 5 to 75 weight-% of at least one anionic polymer, 0.05 to 5 weight-% of at least one water insoluble liquid defoamer and 0.005 to 3 weight-% of at least one polysaccharide, based on 100 weight-% of the composition. The composition gives predictable air content in non-air entrained and air-entrained mortar and concrete.