Colloidal Polymer Inorganic Hybrid Additive for Calcined Clay Concrete
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Solution Overview
Problem
Existing construction compositions containing calcined clay face challenges with slump retention and early strength development, while also requiring high dosages of superplasticizers and often resulting in sticky concrete mixes with high dynamic viscosity.
Innovation Solution
The use of a colloidal polymer inorganic hybrid material as an additive in construction compositions, which includes a cementitious binder, calcined clay, and a polyvalent metal cation selected from Fe3+, Fe2+, Zn2+, Mn2+, Cu2+, Mg2+, Ca2+, Sr2+, Ba2+, and mixtures thereof, along with an anion that forms a low-solubility salt with the polyvalent metal cation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If superplasticizers are added to construction compositions containing calcined clay, then workability is improved, but high dosages are required and slump retention deteriorates
Solution Approach 1:
The patent changes the chemical parameters of the dispersant by using a polycarboxylate-based superplasticizer with specific molecular weight and charge density ranges, optimized for calcined clay blends. This parameter optimization reduces the dosage required while improving slump retention compared to conventional superplasticizers
Solution Approach 2:
The patent employs a composite approach by combining polycarboxylate-based superplasticizer with specific dosages in calcined clay-containing construction compositions, creating an optimized mixture that achieves both workability and slump retention without requiring excessive additive quantities
2Object-affected harmful factors
If calcined clay is used as SCM to reduce clinker content, then CO2 emissions are reduced, but early strength development deteriorates
Solution Approach 1:
The polycarboxylate-based superplasticizer acts as an intermediary that enhances the early reactivity and strength contribution of calcined clay particles. By improving the dispersion and surface activity of calcined clay, the superplasticizer enables these materials to contribute more effectively to early strength development, reducing the traditional strength penalty associated with high calcined clay content
3Object-affected harmful factors
If calcined clay is used in construction compositions, then CO2 impact is reduced, but dynamic viscosity increases causing sticky concrete mixes
Solution Approach 1:
The patent optimizes the molecular parameters of the superplasticizer, specifically selecting polycarboxylate-based polymers with molecular weights and charge densities within specific ranges. These parameter adjustments enable effective dispersion of calcined clay particles at lower dosages, preventing excessive viscosity increase and sticky mix conditions while maintaining high calcined clay content for CO2 reduction
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
This solution effectively improves slump retention and early strength development in construction compositions, while reducing the need for high dosages of superplasticizers and minimizing issues with concrete mix viscosity.
Implementation Method 1
additives of this kind are able to prevent the agglomeration by dispersing existing particles and those newly formed by hydration, and in this way to improve the workability
Implementation Method 2
a polyvalent metal cation selected from Fe3+, Fe2+, Zn2+, Mn2+, Cu2+, Mg2+, Ca2+, Sr2+, Ba2+, and mixtures thereof, along with an anion that forms a low-solubility salt with the polyvalent metal cation
Data Source
AI summary
A colloidal polymer inorganic hybrid material is used as an additive for a construction composition comprising a binder system, the binder system comprising a cementitious binder and at least one supplementary cementitious material, wherein the supplementary cementitious material(s) comprise(s) a calcined clay material, the clay material including at least one non-kaolinitic clay material. The hybrid material comprises at least one polyvalent metal cation, at least one polymeric dispersant which comprises anionic and/or anionogenic groups and polyether side chains, at least one anion which is able to form a low-solubility salt with the polyvalent metal cation, wherein the polyvalent metal cation is present in an amount corresponding to the following formula (1):0.10≤∑ izK, i×nK, iφ×mD≤15(1)and the anion is present in an amount corresponding to the following formula (2):0.01≤∑ lzA, l×nA, l∑ izK, i×nK, i≤1(2)wherein φ is the charge density of the polymeric, mD is the amount of polymeric dispersant, zK,i is the valency of the polyvalent metal cation, nK,i is the molar amount of the polyvalent metal cation, zA,l is the valency of the anion, nA,l is the molar amount of the anion, the indices i, and l are independent of one another and are an integer greater than 0, i is the number of different kinds of polyvalent metal cations and l is the number of different kinds of anions which are able to form a low-solubility salt with the metal cation. The use of the colloidal polymer inorganic hybrid material allows for an effective slump retention.