Self-Healing Construction Joint Seal with Calcium Precipitation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sealing devices for construction joints, particularly in concrete structures, fail to provide a reliable and permanent seal against moisture and reinforcement-damaging substances, as they are prone to cracking and do not effectively self-heal over time.
Innovation Solution
A sealing device with a carrier coated in a composition containing a calcium precipitating agent, latent hydraulic material, rock powder or sand, and a binder, which reacts with water to form calcium carbonate or silicate compounds, creating a self-healing seal through the formation of cement stone or limestone, enhancing adhesion and watertightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bentonite coating is used to seal construction joints, then cracks and cavities are sealed by swelling of bentonite, but the sealing is not permanent and reliable over time
Solution Approach 1:
The patent applies composite materials by combining bentonite with calcium precipitating agents and latent hydraulic materials in the coating composition. This creates a multi-functional sealing system where bentonite provides immediate swelling sealing, while the calcium precipitating agent forms calcium carbonate deposits, and the latent hydraulic material activates over time to continue sealing cracks, thereby achieving both immediate and long-term sealing reliability.
Solution Approach 2:
The patent implements self-service through the latent hydraulic material that remains dormant initially but activates automatically when exposed to moisture over time. This self-activating component continuously produces calcium hydroxide that reacts with carbon dioxide to form calcium carbonate, enabling the coating to self-heal cracks and maintain sealing effectiveness without external intervention throughout the structure's service life.
2Reliability
If chemical sealing using cement and calcium hydroxide is used, then calcium carbonate precipitates to seal joints, but the sealing is limited by carbonate content in cement and CO2 content in ambient air
Solution Approach 1:
The patent applies parameter changes by introducing a calcium precipitating agent that reacts with carbon dioxide at a controlled rate to continuously generate calcium carbonate. Additionally, the latent hydraulic material provides a sustained source of calcium hydroxide over time. This transforms the limited chemical sealing capacity into a continuous, long-term sealing process that is not constrained by the initial carbonate content in cement or ambient CO2 availability.
Solution Approach 2:
The patent implements preliminary action by incorporating the latent hydraulic material into the coating composition before application. This material remains dormant during application and initial curing but activates automatically upon exposure to moisture in the concrete joint, preliminarily preparing the sealing system to continuously produce calcium hydroxide and calcium carbonate for long-term crack sealing and joint protection.
3Reliability
If a coating with sealing material is applied to prevent moisture ingress, then adhesion and watertightness are improved, but the coating may crack and fail to self-heal
Solution Approach 1:
The patent implements self-service through the latent hydraulic material that automatically activates when the coating is exposed to moisture over time. This self-activating component continuously produces calcium hydroxide that reacts with carbon dioxide to form calcium carbonate, enabling the coating to self-heal cracks and maintain sealing effectiveness without external intervention throughout the structure's service life.
Solution Approach 2:
The patent applies composite materials by combining bentonite with calcium precipitating agents and latent hydraulic materials in the coating composition. This creates a multi-functional sealing system where bentonite provides immediate swelling sealing, while the calcium precipitating agent forms calcium carbonate deposits, and the latent hydraulic material activates over time to continue sealing cracks, thereby achieving both immediate and long-term sealing reliability.
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 solution provides a reliable, long-lasting seal that self-heals cracks, ensuring effective prevention of moisture and pollutant ingress, with improved adhesion and watertightness, even after prolonged periods, by forming cement stone or limestone, thus addressing the limitations of prior art.
Implementation Method 1
The calcium precipitating agent is a compound or mixture of compounds which, upon contact with water, cleaves carbonate ions or silicates by a chemical reaction... with the precipitation of calcium carbonate or Calcium silicate
Implementation Method 2
These anions then react with calcium ions originating from the cement contained in the concrete, with the precipitation of calcium carbonate or Calcium silicate
Implementation Method 3
Cement paste is formed by the reaction of dissolved calcium hydroxide from the concrete with the latent hydraulic material from the waterproofing material
Implementation Method 4
The incorporation of the sealing material in a binder leads to a depot effect... cracks are sealed by 'self-healing', i.e. clogging of subsequent cracks caused by the formation of cement stone or limestone
Implementation Method 5
The bentonite layer represents a barrier. Cracks and cavities are caught by the bentonite and sealed purely by swelling of the bentonite
Implementation Method 6
Examples of suitable binders that improve the adhesion of the sealing material without adversely affecting its effect are: plastics, latex, natural or synthetic rubber, crosslinkable polymers, bitumen and mixtures thereof
Data Source
Figure 1
Figure 2A~3B
AI summary
The device (6) for sealing construction joints (4, 5) such as concrete joints, comprises a carrier (7), and a coating (8) applied on the carrier in an area-wise manner, where the coating has a bonding agent, a sealing material, which consists of a calcium aggregating agent and a latent hydraulic material, and a rock flour and/or a rock sand. The aggregating agent is a compound or a mixture of compounds, which splits carbonate ions or silicate ions by a chemical reaction during contacting with water. The bonding agent is a latex dispersion. The carrier is a galvanized carrier sheet. The device (6) for sealing construction joints (4, 5) such as concrete joints, comprises a carrier (7), and a coating (8) applied on the carrier in an area-wise manner, where the coating has a bonding agent, a sealing material, which consists of a calcium aggregating agent and a latent hydraulic material, and a rock flour and/or a rock sand. The aggregating agent is a compound or a mixture of compounds, which splits carbonate ions or silicate ions by a chemical reaction during contacting with water. The bonding agent is a latex dispersion. The carrier is a galvanized carrier sheet and has the coating only on one side lying against the side to be insulated. The coating on the carrier forms a rough surface. An independent claim is included for a joint seal.