Microbial Activation of CFB Fly Ash for Lower Water Demand
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Solution Overview
Problem
CFB fly ash exhibits high water demand, low early strength, and high late expansion rate due to its loose and porous surface, high calcium-sulfur content, and great loss on ignition, limiting its comprehensive utilization in building materials.
Innovation Solution
Utilization of Paenibacillus mucilaginosus LT1906 to activate CFB fly ash by dissolving silicate minerals, reducing II-CaSO4 crystals, and secreting extracellular mucopolysaccharides to reduce water demand and enhance early strength through hydration reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CFB fly ash is used as auxiliary cementitious material, then pozzolanic activity and self-hardening are utilized, but water demand increases and early strength decreases
Solution Approach 1:
The patent applies preliminary action by pre-treating the CFB fly ash with microbial agents and chemical solutions before use in cementitious materials. The fly ash is subjected to activation treatments including microbial fermentation and chemical modification to improve its reactivity and reduce water demand before it is incorporated into concrete or cement formulations.
Solution Approach 2:
The patent employs parameter changes by modifying the physical and chemical properties of CFB fly ash through controlled activation processes. Parameters such as surface area, porosity, calcium-sulfur content, and loss on ignition are adjusted through thermal treatment, microbial action, and chemical modification to optimize performance while reducing water demand.
2Reliability
If CFB fly ash is used as auxiliary cementitious material, then pozzolanic activity and self-hardening are utilized, but early strength decreases
Solution Approach 1:
The patent applies preliminary action by pre-treating the CFB fly ash with microbial agents and chemical solutions before use in cementitious materials. The fly ash is subjected to activation treatments including microbial fermentation and chemical modification to improve its reactivity and reduce water demand before it is incorporated into concrete or cement formulations.
Solution Approach 2:
The patent uses composite materials by combining CFB fly ash with microbial agents, chemical additives, and other cementitious components to create an activated composite material. This composite approach enhances early strength development while maintaining the pozzolanic properties of the fly ash through synergistic interactions between different materials.
3Reliability
If CFB fly ash is used as auxiliary cementitious material, then pozzolanic activity and self-hardening are utilized, but late expansion rate increases
Solution Approach 1:
The patent applies preliminary anti-action by implementing pre-treatment processes that counteract the harmful effects of high calcium-sulfur content and loss on ignition before they can cause excessive late expansion. The activation treatments modify the fly ash composition in advance to prevent harmful expansion reactions during the curing and service periods of the cementitious material.
Solution Approach 2:
The patent employs parameter changes by modifying the physical and chemical properties of CFB fly ash through controlled activation processes. Parameters such as surface area, porosity, calcium-sulfur content, and loss on ignition are adjusted through thermal treatment, microbial action, and chemical modification to optimize performance while reducing water demand.
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 activation process improves the water demand and early strength of CFB fly ash, enhancing its utilization in building materials by increasing active SiO2 content, reducing gypsum expansion, and improving rheological properties.
Implementation Method 1
The Paenibacillus mucilaginosus is used to activate an activity of the CFB fly ash, which effectively ameliorates a large water demand and a low early strength of the CFB fly ash as a cementitious material
Implementation Method 2
The Paenibacillus mucilaginosus can also secrete a large amount of extracellular mucopolysaccharide, which is combined with free water failed to react effectively through hydrogen bonds
Implementation Method 3
accelerate the formation of hydrated calcium silicate gel (C—S—H), thereby improving a gelation strength
Data Source
AI summary
The present disclosure provides a Paenibacillus mucilaginosus LT1906 and use thereof, and a microorganism-activated circulating fluidized bed (CFB) fly ash-based cementitious material and a preparation method and use thereof, belonging to the technical field of cementitious materials. The Paenibacillus mucilaginosus LT1906 has a deposit number of CGMCC No. 21337. The strain is capable of dissolving silicate minerals and aluminosilicate minerals in the CFB fly ash to increase dissolution of active SiO2. The strain is used for activating the CFB fly ash-based cementitious material, to ameliorate a large water demand and a low early strength of the cementitious material, thereby improving comprehensive utilization of the CFB fly ash in the field of building materials.