Waterproofing Mortar Using Hydraulic Lime and Polymers

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Solution Overview

Problem

Current waterproofing methods for porous construction materials, particularly those using Portland cement, face challenges such as high CO2 emissions, shrinkage leading to micro-cracks, and brittleness, as well as the need for solvents and hazardous chemicals in liquid applied membranes, which are undesirable for environmental, health, and safety reasons.

Innovation Solution

A process involving a mixture of natural hydraulic lime, pozzolanic materials, aggregates, and synthetic polymers with a minimal content of Portland cement, applied to porous construction materials to reduce water uptake and enhance adhesion and durability, while minimizing environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Portland cement is used as binder in waterproofing mortars, then desired waterproofing properties are achieved, but CO2 emissions increase significantly

Engineering Contradiction:
Improvewaterproofing performanceVSAvoidCO2 emissions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing Portland cement with hydraulic lime as the binder, fundamentally altering the material's chemical properties to achieve lower CO2 emissions while maintaining waterproofing functionality through the hydraulic properties of lime

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite waterproofing mortar composition combining hydraulic lime with pozzolanic materials and synthetic polymers, where the composite structure provides both the waterproofing performance and the environmental benefits of reduced CO2 emissions

Inventive Principle:
Principle #40Composite materials

2Reliability

If Portland cement is used as binder, then waterproofing properties are achieved, but shrinkage during hardening causes micro-cracks and reduces mechanical strength

Engineering Contradiction:
Improvewaterproofing performanceVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the binder material from Portland cement to hydraulic lime, which has different hardening characteristics that reduce shrinkage and prevent micro-cracks, thereby improving mechanical strength while maintaining waterproofing performance

Inventive Principle:
Principle #35Parameter changes

3Reliability

If Portland cement is used as binder, then waterproofing properties are achieved, but hardness and brittleness increase

Engineering Contradiction:
Improvewaterproofing performanceVSAvoidhardness and brittleness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the binder chemistry from Portland cement to hydraulic lime, fundamentally altering the mechanical properties of the hardened material to reduce hardness and brittleness, making it more suitable for restoration work on weak substrates while preserving waterproofing functionality

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If liquid applied membranes based on reactive organic binders are used, then easier application is achieved, but solvents and hazardous chemicals are required

Engineering Contradiction:
Improveapplication easeVSAvoidhazardous chemicals
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent changes the binder type from reactive organic binders to inorganic hydraulic lime binders, fundamentally altering the chemistry to eliminate the need for solvents and hazardous chemicals while maintaining liquid applied membrane characteristics and ease of application

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive and hazardous organic chemical systems with a simpler, safer inorganic lime-based system that achieves the same application characteristics without the harmful byproducts

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 process significantly reduces water absorption and capillary water uptake, improves adhesion to cementitious materials, and minimizes shrinkage, leading to less cracking and reduced stress on the construction material, thus providing effective waterproofing with lower environmental footprint.

Implementation Method 1

The compositions are based on hydrated lime and pozzolanic material such as synthetic precipitated silica or silica gel

Methodology Applied
Scientific EffectPozzolanic reaction: Chemical Bonding

Implementation Method 2

2 - 30 wt.-% of at least one synthetic polymer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

Water is further transported by capillary suction from the surface into the bulk of these materials

Methodology Applied
Scientific EffectCapillary suction: Capillary Action

Data Source

PatentEP3805182B1Process for the waterproofing of porous construction materials
Publication Date: 2023.05.03 SIKA TECH AG

AI summary

The present invention relates to a process for the waterproofing of porous construction materials, said process comprising the steps of - mixing water and a composition C, the composition C comprising, in each case based on the total weight of the composition C, a) 2 - 15 wt.-% of at least one binder selected from natural hydraulic lime (NHL), formulated lime (FL), and hydraulic lime (HL), b) 1 - 20 wt.-% of at least one pozzolanic material, c) 40 - 80 wt.-% of at least one aggregate, d) 2 - 30 wt.-% of at least one synthetic polymer, and wherein the content of Portland cement in said composition C is < 3 wt.-%, - applying the mixture thus obtained to a porous construction material, and - optionally hardening the applied mixture.