Concrete Mix Carbonation Timing and Dose Control
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Solution Overview
Problem
The cement industry faces challenges in reducing greenhouse gas emissions, particularly from carbon dioxide, which accounts for 5% of global CO2 emissions, and existing methods for incorporating carbon dioxide into concrete mixes are inefficient and can affect the durability of mature concrete structures.
Innovation Solution
A method and apparatus for carbonating concrete mixes by delivering carbon dioxide during the mixing process, specifically within 3 minutes of starting the mix and for a duration of 10 seconds to 4 minutes, using a dose of 0.01-1.0% by weight cement, which can be implemented in stationary or transportable mixers like ready-mix trucks, ensuring homogeneous distribution of nano-scale carbonate reaction products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If carbon dioxide is delivered to concrete mix during mixing, then compressive strength is enhanced and CO2 emissions are reduced, but the process requires precise timing control within 3 minutes of mixing start
Solution Approach 1:
The system pre-positions the CO2 delivery mechanism to activate automatically at the optimal moment (within 3 minutes of mixing start) without requiring manual intervention or complex real-time control systems. The delivery system is prepared in advance and triggers at the predetermined optimal time window.
2Manufacturing precision
If carbon dioxide is delivered within 3 minutes of mixing start for 10-4 minutes, then homogeneous distribution of carbonate reaction products is achieved, but the delivery system must be integrated with the mixing process
Solution Approach 1:
The CO2 delivery system is integrated with the existing mixing process by combining the two functions into a single operational sequence. The system merges CO2 injection with the mixing operation, allowing simultaneous achievement of homogeneous distribution without requiring separate complex delivery and mixing systems.
Solution Approach 2:
The system controls the CO2 delivery parameters (timing within 3 minutes, duration of 10-4 minutes, dose of 0.01-1.0% by weight cement) to optimize the chemical reaction conditions. By adjusting these parameters, homogeneous distribution of carbonate reaction products is achieved while simplifying the overall system integration.
3Object-generated harmful factors
If a dose of 0.01-1.0% by weight cement of carbon dioxide is used, then significant CO2 emissions savings are achieved, but the delivery system must precisely control the dose amount
Solution Approach 1:
The system uses predetermined dose parameters (0.01-1.0% by weight cement) that have been optimized through previous testing of multiple doses on multiple test mixes. This allows precise dose control without requiring complex real-time measurement or adjustment systems, as the optimal dose range is established in advance.
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 approach enhances the compressive strength of concrete, reduces the amount of cement needed, and achieves significant CO2 emissions savings by integrating carbon dioxide into freshly hydrating cement, avoiding durability issues associated with mature concrete carbonation.
Implementation Method 1
contacting a mixture of a cement binder and water with carbon dioxide during some part of the mixing of the cement mix
Implementation Method 2
freshly hydrating cement
Data Source
AI summary
The invention provides compositions and methods directed to carbonation of a cement mix during mixing. The carbonation may be in a stationary mixer or a transportable mixer, such as a drum of a ready-mix truck.