Recycled Aggregate Preparation via Thermal Vitrification
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Solution Overview
Problem
Recycled aggregates from waste materials in concrete are prone to high chloride ion release, which can lead to corrosion and degradation of reinforced concrete, especially when exposed to external chlorides or containing hazardous substances like metals and semi-metals, affecting the durability and safety of concrete structures.
Innovation Solution
A process involving mixing waste materials, such as light or heavy ashes, with cement and silicates, followed by curing and crushing stages, to produce aggregates with low chloride and metal release, suitable for use as inert components in concrete formulations, where the waste materials are pre-treated to optimize grain size, moisture, and metal content, and pH adjustments are made to enhance stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If recycled aggregates are produced from waste materials, then the quantity of recycled materials in concrete is increased, but chloride ion release increases leading to corrosion and degradation
Solution Approach 1:
The patent applies this principle by treating waste materials containing chlorides and hazardous substances through a controlled thermal treatment process. The harmful chloride ions and contaminants are transformed into a stable, inert glassy phase within the aggregate structure, converting the harmful waste material into a beneficial recycled aggregate that can be safely used in concrete without releasing chlorides.
Solution Approach 2:
The patent employs parameter changes by controlling the thermal treatment parameters (temperature, duration, atmosphere) to achieve complete vitrification of the waste material. By adjusting these parameters, the chloride content and hazardous substances are locked into a stable crystalline or glassy structure, fundamentally changing the chemical and physical properties of the waste material to eliminate chloride release while maintaining aggregate functionality.
2Productivity
If waste materials are used as aggregates, then productivity and sustainability are improved, but reliability of concrete structure deteriorates due to corrosion risks
Solution Approach 1:
The patent converts harmful waste materials into reliable aggregate products by applying thermal treatment that stabilizes all hazardous components. This transformation maintains the productivity benefits of using recycled materials while eliminating the reliability concerns associated with chloride-induced corrosion, as the treated aggregates demonstrate long-term structural stability.
Solution Approach 2:
The patent creates a composite structure within the recycled aggregate by combining the original waste material matrix with newly formed stable crystalline phases and glassy binders resulting from thermal treatment. This composite structure locks chloride ions and hazardous substances in place, preventing their release while maintaining the mechanical properties needed for reliable concrete performance.
3Object-generated harmful factors
If traditional waste treatment methods are used, then chloride release is reduced, but the complexity and cost of the treatment process increases
Solution Approach 1:
The patent merges multiple treatment objectives (chloride stabilization, hazardous substance immobilization, aggregate size control, and material activation) into a single integrated thermal treatment process. This consolidation achieves comprehensive chloride release reduction without requiring separate treatment steps, thereby reducing overall process complexity while maintaining effective harm reduction.
Solution Approach 2:
The patent uses optimized parameter changes in the thermal treatment process to achieve effective chloride stabilization at practical temperature and time levels. By carefully controlling these parameters, the process achieves complete vitrification and contaminant immobilization without requiring excessively high energy inputs or complex process equipment, balancing effectiveness with operational simplicity.
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 resulting recycled aggregates exhibit reduced chloride and metal release, improving the durability and safety of concrete by reducing corrosion risks and allowing for increased use of recycled materials in concrete, while minimizing environmental impact through reduced need for hazardous waste treatment.
Implementation Method 1
first curing of the material in arrival from stage (a)
Implementation Method 2
mixing a waste material with cement and at least one silicate
Implementation Method 3
crushing of the material subjected to the first curing
Data Source
AI summary
The present invention relates in general terms to a recycled aggregate and a process for preparation thereof. Said process, in particular, is characterized by a controlled mixing stage of a waste material with cement, in a presence of at least one silicate, followed by curing and crushing steps. The composition of the invention, in the form for example of pseudo-spherical aggregates, is useful in particular as an inert component for the formulation of concretes and the like and further makes possible the recovery of waste material.