Low-Carbon Mortar Using Slag Activator
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Solution Overview
Problem
Current mortar formulations based on calcium aluminosilicate derivatives, such as activated blast furnace slag, face limitations in reactivity at low temperatures, which affects their performance in cold conditions and contributes to a significant carbon footprint due to high energy consumption and CO2 emissions from clinker manufacturing processes.
Innovation Solution
A dry mortar composition utilizing ground granulated aluminous slag as an activator, which is rich in aluminum and has a low silica content, combined with a calcium aluminosilicate derivative, calcium sulfate, and minimal alkaline base, to enhance reactivity and reduce carbon footprint by optimizing particle fineness and reducing Portland cement usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Portland cement is used as the hydraulic binder, then the mortar achieves good reactivity and mechanical strength, but the carbon footprint and CO2 emissions increase significantly
Solution Approach 1:
The patent changes the chemical composition parameters of the hydraulic binder by using ground granulated blast furnace slag (GGBS) as the primary binder instead of Portland cement. The slag is activated by calcium sulfate sources (gypsum, anhydrite) and alkaline materials to achieve reactivity comparable to cement while dramatically reducing CO2 emissions by eliminating the high-temperature clinkering process.
Solution Approach 2:
The patent recovers and utilizes ground granulated blast furnace slag, which is an industrial by-product of steelmaking, as the primary hydraulic binder. This transforms a waste material into a valuable binding agent, reducing the need for cement production and associated emissions while maintaining structural performance.
2Object-generated harmful factors
If the amount of Portland cement is reduced to less than 1% by weight, then the carbon footprint is significantly reduced and corrosive product marking is avoided, but the reactivity at low temperatures (below 10°C) becomes limited
Solution Approach 1:
The patent introduces calcium sulfate sources (gypsum, anhydrite, or calcium sulfate aluminate cement) as intermediary materials that activate the ground granulated blast furnace slag. These intermediaries provide calcium ions and sulfate ions that facilitate the formation of ettringite and other hydraulic phases, enabling the slag to exhibit adequate reactivity and setting characteristics even at low temperatures with minimal Portland cement content.
Solution Approach 2:
The patent creates a composite hydraulic binder system combining ground granulated blast furnace slag with calcium sulfate sources and alkaline activators. This composite material leverages the synergistic effects of its components: the slag provides the bulk binding material, calcium sulfate sources provide activation and setting control, and alkalines enhance reactivity, together achieving low-temperature performance with reduced cement content.
3Object-generated harmful factors
If ground granulated blast furnace slag is used as the hydraulic binder, then the carbon footprint is reduced, but the reactivity at low temperatures remains insufficient
Solution Approach 1:
The patent modifies the chemical and physical parameters of the binder system by incorporating calcium sulfate sources and alkaline activators with the ground granulated blast furnace slag. These additions change the activation mechanism and reaction kinetics, enabling the slag to achieve adequate reactivity and setting time even at low temperatures while maintaining the low-carbon advantage.
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 composition exhibits improved reactivity at low temperatures, significantly reducing CO2 emissions and achieving mechanical strength and setting time comparable to traditional Portland cement-based mortars, while minimizing environmental impact.
Implementation Method 1
a hydraulic binder comprising at least one calcium aluminosilicate derivative, at least one ground granulated aluminous slag comprising less than 30% by weight of silica
Implementation Method 2
at least one calcium aluminosilicate derivative activated by an industrial by-product
Data Source
AI summary
The invention relates to a dry mortar composition comprising: a hydraulic binder comprising at least one calcium aluminosilicate derivative, at least one ground granulated aluminous slag comprising less than 30 wt.-% silica, and at least one source of calcium sulphate; aggregates and/or fillers; and at least one base in an amount of less than or equal to 0.5% of the total weight of the dry mortar composition.