AAC Building Block Composite Rebar for Alkali and Heat Resistance
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Solution Overview
Problem
Reinforced building blocks made of autoclaved aerated concrete are not resistant to alkali and high operating temperatures due to the chemical nature of anhydride-based epoxy binders, which affects their physical-mechanical properties and durability.
Innovation Solution
The use of composite rebars formed from fibrous carriers and a hardened composition of epoxy compounds and diamines/polyamines in a specific stoichiometric ratio, providing improved chemical resistance and heat resistance, is employed to enhance the stability and mechanical properties of autoclaved aerated concrete building blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If anhydride-based epoxy binders are used in composite rebars, then the rebars can be manufactured with standard epoxy resin processes, but the rebars lose resistance to alkali and high operating temperatures, deteriorating their durability and physical-mechanical properties
Solution Approach 1:
The patent changes the chemical parameters of the epoxy binder by replacing anhydride-based epoxy resin with amine-based epoxy resin. This parameter change fundamentally alters the chemical composition and properties of the binder, enabling it to resist alkali and high temperatures while maintaining manufacturability through standard impregnation processes.
Solution Approach 2:
The patent creates a composite material system combining fibrous carrier (glass, carbon, or basalt fibers) with amine-based epoxy resin. This composite structure provides both the mechanical strength of the fibers and the chemical resistance of the amine-based matrix, achieving durability in alkaline and high-temperature environments while retaining ease of manufacture.
2Device complexity
If conventional epoxy binders are used in composite rebars, then the production process remains simple and cost-effective, but the physical-mechanical properties deteriorate under alkaline curing conditions and high operating temperatures
Solution Approach 1:
The patent modifies the chemical parameters of the epoxy system by substituting anhydride-based resin with amine-based resin. This change maintains the simplicity of the production process while dramatically improving the physical-mechanical properties, particularly strength and stability under alkaline curing conditions and elevated temperatures.
3Ease of manufacture
If standard epoxy resin impregnation is used for fibrous carriers, then the manufacturing process is straightforward and economical, but the composite rebars cannot withstand high operating temperatures and alkaline environments
Solution Approach 1:
The patent changes the chemical composition parameter of the epoxy resin from anhydride-based to amine-based. This parameter change maintains the straightforward and economical impregnation process while providing resistance to alkaline environments and high operating temperatures, eliminating susceptibility to these harmful factors.
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 composite rebars exhibit superior physical and mechanical properties, offering enhanced resistance to alkaline environments and higher operating temperatures, making them suitable for improved heat resistance and durability in building applications.
Implementation Method 1
a hardened composition formed from B1) at least one epoxy compound and B2) at least one diamine and/or polyamine in a stoichiometric ratio of the epoxy compound B1) to the diamine and/or polyamine component B2) of 0.8:1 to 2:1
Implementation Method 2
rebars formed essentially from A) at least one fibrous carrier and B) and a hardened composition
Implementation Method 3
Concrete curing during the first 28 days is performed in a highly alkaline reaction medium with exothermic effect (up to 60° C.)
Data Source
AI summary
The present invention is directed to a reinforced building block made of autoclaved aerated concrete (AAC) comprising rebars formed essentially from A) at least one fibrous carrier and B) and a hardened composition formed from B1) at least one epoxy compound and B2) at least one diamine and/or polyamine in a stoichiometric ratio of the epoxy compound B1) to the diamine and/or polyamine component B2) of 0.8:1 to 2:1, as matrix material, and C) optionally further auxiliaries and additives and to methods of production thereof.