Cementitious Compositions With Redox-Activated Non-Hydration Strength
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Solution Overview
Problem
Existing concrete technologies face challenges with premature strength gain during transport and placement, leading to limited finishing windows and integration issues in multi-layer applications, as well as rebound and bonding problems in shotcrete applications, due to the use of conventional accelerators.
Innovation Solution
Incorporating a polymerizable component system within the cementitious matrix, activated by a redox pair, to form a gel-like structure that increases non-hydration strength and extends the workability window without relying on hydration dynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional accelerators are used to increase early strength gain in concrete, then strength development is improved, but the finishing window closes rapidly and workability is reduced
Solution Approach 1:
The patent segments the strength development mechanism into two independent systems: (1) conventional cement hydration for long-term strength, and (2) polymerization of vinyl monomers for early-age strength. This segmentation allows each system to operate independently, with the polymerization system providing early strength without interfering with the hydration timeline and finishing window.
Solution Approach 2:
The patent introduces polymerization as an intermediary mechanism that bridges the gap between immediate strength requirements and the natural hydration timeline. The polymer network forms an intermediate structure that provides early strength support without accelerating the hydration process, thereby maintaining the finishing window.
2Reliability
If accelerators are added to concrete just before pouring to avoid premature setting, then setting control is improved, but strength gain becomes excessively rapid causing finishing difficulties
Solution Approach 1:
The patent extracts the strength-generating function from the setting mechanism. By using polymerization separately from cement hydration, the invention removes the coupling between setting control and strength gain rate that exists in conventional accelerator systems. This allows setting to be controlled by hydration while strength is provided by the independent polymerization process.
Solution Approach 2:
The polymerization process is initiated in advance of the finishing operation, creating a preliminary strength structure that supports the concrete during finishing. This preliminary action occurs through monomer addition and polymerization before the concrete is finished, providing head start on strength development without affecting the finishing window.
3Strength
If quick strength gain is achieved to support subsequent concrete layers, then structural support is improved, but layer integration deteriorates due to premature stiffening
Solution Approach 1:
The patent applies local quality by creating a dual-structure concrete where the polymer network provides localized early strength in the matrix without affecting the overall plasticity and bonding capability of the concrete. The polymerized regions provide support while the unhydrated and hydrating cementitious material maintains workability for integration with subsequent layers.
4Strength
If high elastic modulus is achieved through accelerators in shotcrete, then structural rigidity is improved, but rebound increases due to material bouncing off the substrate
Solution Approach 1:
The patent changes the parameters of early-age concrete by introducing polymerization, which modifies the stress-strain characteristics and energy absorption properties. The polymer network provides a more ductile, energy-absorbing structure that reduces elastic rebound compared to the rigid, high-modulus structure created by conventional accelerators.
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 polymerization process enhances early-age strength and yield stress properties, allowing for wider finishing times, improved layer integration, reduced rebound, and better bonding in concrete applications.
Implementation Method 1
activated by a redox pair
Implementation Method 2
the polymerization process enhances early-age strength
Data Source
AI summary
Described are compositions and methods for controlled strength development in a hydratable cementitious material, and more particularly to the use of polymerizable monomer components, which are initiated and activated by a redox pair which are mixed in controlled fashion, for enhancing non-hydration strength within the matrix of the plastic hydratable cementitious material before setting of the cementitious material begins. Exemplary applications include minimizing pressures on formwork for high fluid ready-mix applications, enhancing support and bonding properties for integrated concrete slab work and other sequential applications, or facilitating speedy 3D printing applications, among other unique possibilities.