Calcium Sulfate Construction Formulation for Rapid Low-Stress Setting
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Solution Overview
Problem
Cementitious smoothing compounds harden under tension, leading to brittleness and cracking, while calcium sulfate-based systems dry too slowly, hindering rapid construction progress and timely readiness for covering.
Innovation Solution
A construction chemical formulation comprising 20-80% calcium sulfate binder, 1-15% ettringite former, 0.01-5% activator, 8-60% filler, and 0.1-10% redispersible dispersion powder, which controls ettringite formation to quickly bind water and reduce drying time to less than six hours.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cementitious binder systems are used to achieve fast hardening and construction progress, then productivity is improved, but the hardened compound becomes brittle and cracks form, reducing reliability
Solution Approach 1:
The patent uses a composite binder system combining calcium sulfate hemihydrate (60-80 wt%) with Portland cement (10-30 wt%) and calcium aluminate cement (5-20 wt%). This composite approach leverages the fast setting of calcium sulfate while the cement components provide tensile strength and crack resistance, resolving the contradiction between productivity and reliability.
Solution Approach 2:
The patent modifies the chemical composition parameters of the binder system by incorporating specific ratios of calcium sulfate, Portland cement, and calcium aluminate cement. Additionally, superplasticizers and admixtures are used to control hydration rates and microstructure development, enabling fast hardening without brittleness.
2Reliability
If calcium sulfate-based binder systems are used to reduce brittleness and cracking, then reliability is improved, but drying time increases excessively, reducing productivity
Solution Approach 1:
The patent controls the drying time by adjusting the calcium sulfate content to 60-80 wt% (optimizing the balance between low brittleness and acceptable drying time), using Portland cement and calcium aluminate cement to accelerate hardening, and incorporating superplasticizers and admixtures to control hydration kinetics and reduce excess water, thereby maintaining reliability while improving productivity.
Solution Approach 2:
The patent replicates the beneficial properties of natural ettringite formation by adding calcium sulfate and aluminate sources, which crystallize during hardening to bind water chemically. This controlled crystallization process mimics natural gypsum setting while preventing excessive drying time through optimized composition ratios.
3Productivity
If high cement content is used to achieve fast hardening, then productivity is improved, but the system hardens under high tension, increasing brittleness and reducing reliability
Solution Approach 1:
The patent distributes the binding function across three materials: calcium sulfate hemihydrate (60-80 wt%) for initial set, Portland cement (10-30 wt%) for strength development, and calcium aluminate cement (5-20 wt%) for rapid early strength. This distribution reduces internal tension compared to high-cement formulations while maintaining fast hardening and high reliability.
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 formulation achieves rapid drying and low-tension hardening, ensuring timely readiness for covering and durable adhesive bonding with increased peel values, reducing the risk of cracking and enabling fast construction progress.
Implementation Method 1
controls ettringite formation to quickly bind water and reduce drying time to less than six hours
Implementation Method 2
Since cement hydration is accompanied by a change in volume, systems of this kind harden under high tension
Implementation Method 3
c) from 0.01 to 5 wt. % of at least one activator
Implementation Method 4
e) from 0.1 to 10 wt. % of at least one redispersible dispersion powder
Implementation Method 5
The formulation achieves rapid drying and low-tension hardening, ensuring timely readiness for covering and durable adhesive bonding with increased peel values
Data Source
AI summary
The present invention relates to a quick and low-stress setting chemical formulation for construction, containing at least one binding agent on the basis of calcium sulfate, at least an ettringite-forming agent, at least one activator, at least one filler, at least one redispersable dispersion powder and optionally additives and to the use of the chemical formulation for construction for producing thin-layered balancing masses, self running and solid fillers, screed binding agents or screed mortars, tile adhesive mortars, jointing mortars and sealing sludges.