Hydrous Graphene Oxide Admixture for Stronger, Lower-Permeability Concrete
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern high-strength concrete faces challenges with cracking and spalling due to porosity, and existing additives like nanocarbon and micronized biochar are costly and difficult to disperse effectively, while supplementary cementitious materials and advanced admixtures face supply uncertainties and high costs.
Innovation Solution
A low-cost, scalable process using high-shear liquid phase exfoliation with a dispersant to produce hydrous bio-graphene oxide (hBGO) for concrete, which enhances hydration and micro-reinforcement, improving strength and durability without significant cost increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If nanocarbon additives are used to improve concrete strength, then compressive and flexural strength are enhanced, but the cost becomes prohibitive and the van der Waals forces cause agglomeration that inhibits effective dispersion
Solution Approach 1:
The patent uses a dispersant as an intermediary substance to overcome the strong van der Waals forces between nanocarbon particles. The dispersant mediates the interaction between nanocarbon additives and concrete matrix, preventing agglomeration and enabling effective dispersion while maintaining the strength-enhancing benefits of nanocarbon at low costs
Solution Approach 2:
The patent changes the physical and chemical parameters of the nanocarbon additives through controlled oxidation to create graphene oxide with modified surface properties. This parameter change reduces the strong van der Waals forces and improves dispersibility in the concrete matrix while maintaining the reinforcement benefits
2Strength
If particle size of biochar is reduced to improve dispersion and strength, then concrete performance is enhanced, but the cost of comminution becomes prohibitively expensive
Solution Approach 1:
The patent replaces expensive mechanical comminution systems with a chemical oxidation approach. Instead of using ball mills, attritors, or sonicators to reduce particle size, the process uses chemical oxidation to transform biochar into graphene oxide, achieving the desired particle size reduction and dispersion improvement at lower cost
Solution Approach 2:
The patent changes the material form from solid biochar particles to oxidized graphene oxide through chemical transformation. This parameter change achieves effective dispersion and strength enhancement without requiring expensive mechanical comminution equipment
3Reliability
If supplementary cementitious materials like fly ash and slag are used to reduce porosity, then cracking and spalling are mitigated, but the cost increases and supply uncertainties arise
Solution Approach 1:
The patent uses graphene oxide, which can be produced at low cost from biomass waste, as a replacement for expensive supplementary cementitious materials like fly ash and slag. The graphene oxide provides similar or superior performance in reducing porosity and preventing cracking at lower cost with more stable supply
Solution Approach 2:
The patent creates a composite material system where graphene oxide is integrated into the concrete matrix to provide reinforcement and porosity control. This composite approach achieves the desired reliability improvements while avoiding dependence on costly and supply-unstable traditional SCMs
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
hBGO provides enhanced compressive and flexural strength, reduced permeability, and improved freeze-thaw resistance in concrete, while maintaining workability and reducing the need for other admixtures, with potential for on-site production.
Implementation Method 1
subjecting graphitic carbon in water or an aqueous solution to a high-shear environment in the presence of a dispersing agent to exfoliate graphene oxide
Implementation Method 2
subjecting graphitic carbon in water or an aqueous solution to a high-shear environment in the presence of a dispersing agent
Data Source
AI summary
An aqueous dispersion of graphene oxide is prepared in an additive process by subjecting graphitic carbon, such as biochar, in water or an aqueous solution to a high-shear environment in the presence of a dispersing agent to exfoliate graphene oxide. An intercalating agent may be added to facilitate exfoliation, and optionally neutralized. The graphitic carbon may be pre-processed by wet milling prior to exfoliation. The aqueous dispersion of graphene oxide may be used as a concrete admixture in a concrete composition.