Concrete Contact Layer for Watertight Adhesive Sealing
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Solution Overview
Problem
Existing sealing elements for reinforced concrete structures fail to achieve adequate adhesion and watertightness due to inadequate bonding with concrete, especially when exposed to alkaline conditions and weathering, leading to water leaks.
Innovation Solution
A concrete contact layer comprising polyurethane or polyurethane copolymers is applied to the adhesive layer, which is designed to be temporarily unstable under alkaline conditions, allowing it to swell and dissolve, enhancing adhesion and bonding with concrete.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a protective coating is applied to the adhesive layer to protect it from weathering and oxidation, then the adhesive is protected from dust, dirt, and environmental influences, but the adhesion to concrete is insufficient and water leaks occur
Solution Approach 1:
The concrete contact layer is designed with dynamically changing properties: it provides protection initially but degrades under alkaline conditions and UV radiation to become adhesive. This dynamic transformation allows the same layer to serve both protective and bonding functions at different stages.
Solution Approach 2:
The concrete contact layer undergoes parameter changes in response to environmental conditions. Its breaking strength reduces from 100% to at least 20% under alkaline conditions, and it becomes sticky and dissolves upon prolonged exposure to fresh alkaline concrete, transforming from a protective barrier to an adhesive interface.
2Stability of the object's composition
If a stable protective coating is used to withstand chemical and physical changes during outdoor exposure, then weather resistance is improved, but adhesion to concrete deteriorates
Solution Approach 1:
The concrete contact layer transitions from a stable protective state to an unstable adhesive state. It is temporarily stable during storage and handling but becomes unstable under alkaline conditions and UV radiation, allowing it to degrade and bond with concrete effectively.
Solution Approach 2:
The harmful effects of alkaline conditions and UV radiation, which typically degrade materials, are converted into beneficial effects that activate the adhesive properties of the concrete contact layer. The degradation process under these conditions is what enables the layer to bond with concrete.
3Ease of operation
If the concrete contact layer is made stable and weather-resistant, then protection during storage and handling is improved, but adhesion to concrete and watertightness deteriorate
Solution Approach 1:
The concrete contact layer exhibits dynamic stability: it remains stable during storage and handling for ease of operation, but degrades under alkaline conditions and UV radiation to provide adhesion and watertightness during service. This time-dependent behavior resolves the contradiction between handling ease and performance.
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 temporary instability of the concrete contact layer improves adhesion and watertightness, ensuring a strong bond with concrete even under alkaline conditions, preventing water infiltration.
Implementation Method 1
the concrete contact layer is a temporarily stable layer and the breaking strength of the concrete contact layer after storage in an aqueous 0.1 M NaHCO3 for a period of seven days at 23 °C is reduced to at least 20%, preferably to at least 10% and particularly preferably to at least 5% compared to the breaking strength of the concrete contact layer without storage
Implementation Method 2
The concrete contact layer according to the invention is only a temporarily resistant layer that degrades under alkaline conditions as well as upon heating and/or UV radiation
Implementation Method 3
The adhesive layer is a flat, adhesive structure and may contain water-swellable components that swell upon contact with water, thus completely filling the space to be sealed
Implementation Method 4
unprotected, exposed adhesive layers of such flat sealing elements tend to oxidize even during brief exposure to the elements if the sealing membrane is applied in a formwork situation with adhesives facing outwards. Oxidized surfaces do not adhere to the subsequently poured concrete, and the exposed adhesive surface tends to deteriorate due to weathering and dust
Data Source
Figure 1~2D
Figure 3
AI summary
The invention relates to a sealing element (10) for building waterproofing, comprising a stretchable adhesive layer (11), wherein a concrete contact layer (12) comprising polyurethanes or polyurethane copolymers is applied to the adhesive layer (11), wherein the concrete contact layer (12) is a temporarily stable layer and the breaking strength of the concrete contact layer (12) is reduced to at least 20%, preferably at least 10% and particularly preferably at least 5% after storage in an aqueous 0.1 M NaHCO3 solution for a period of seven days at 23 °C compared to the breaking strength of the concrete contact layer without storage.