Sustainable 3D Printable Mortar

Using Locally Harvested Materials in the UAE

Eco-friendly construction solutions with zero Portland cement

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Project Overview

This project presents comprehensive research and development of sustainable 3D printable mortar formulations using locally harvested materials in the United Arab Emirates (UAE). The primary objective was to develop mortar recipes that eliminate or significantly reduce Portland cement content while incorporating local materials such as crushed seashells, desert sand, and agricultural waste.

The developed formulations achieve 70-90% reduction in carbon footprint compared to conventional Portland cement mortars while maintaining adequate mechanical properties for architectural and non-structural applications.

70-90%

Carbon Footprint Reduction

100%

Portland Cement Elimination

4

Specialized Formulations

35-40 MPa

Compressive Strength

Local Materials

Crushed Seashells

Abundant along the UAE coastline and a significant waste stream from the seafood industry. Primarily composed of calcium carbonate (CaCO₃, >90%).

  • Improves sulfate resistance
  • Increases porosity for better insulation
  • Optimal usage: Up to 20% as aggregate

Desert Dune Fines

Abundantly available in the UAE, covering approximately three-quarters of the total land surface area. Primarily composed of silica (SiO₂, 85-95%).

  • Enhances density and strength
  • Improves durability properties
  • Optimal usage: 20-25% replacement of primary precursors

Palm Fibers

Sourced from date palm trees, which are abundant in UAE. Requires alkali pre-treatment for optimal performance.

  • Improves flexural strength
  • Reduces brittleness
  • Increases ductility
  • Optimal content: 0.8% by weight

Banana Fibers

Sourced from the pseudo-stem of banana plants. Composed of lignocellulosic bast fibers with high tensile strength.

  • Increases flexural strength by ~25%
  • Significantly improves crack resistance
  • Creates multi-scale reinforcement system

Sustainable Mortar Recipes

Base Geopolymer Mortar

Composition

Component Percentage by Weight Function
Ground Granulated Blast Furnace Slag (GGBFS) 60% Primary aluminosilicate precursor
Desert Dune Fines (DDF) 20% Secondary precursor, improves density
Crushed Seashells (≤5mm) 15% Calcium source, partial aggregate
Sodium Silicate (Na₂SiO₃) 3% Silica source, improves strength
Sodium Hydroxide (NaOH, 10M) 2% Activator

Properties

  • Initial Setting Time: 45-60 minutes
  • Yield Stress: 1.5-2.0 kPa
  • Structural Build-up Rate: 0.5-0.7 kPa/min
  • 28-day Compressive Strength: 35-40 MPa
  • Water Absorption: <10%
  • Carbon Footprint Reduction: 80-85%

Recommended Applications

Best suited for exterior walls, structural elements, and applications requiring high durability and chemical resistance.

Fiber-Reinforced Geopolymer Mortar

Composition

Component Percentage by Weight Function
Ground Granulated Blast Furnace Slag (GGBFS) 58% Primary aluminosilicate precursor
Desert Dune Fines (DDF) 20% Secondary precursor, improves density
Crushed Seashells (≤5mm) 15% Calcium source, partial aggregate
Chopped Palm Fibers (6-12mm length) 0.8% Reinforcement, crack resistance
Chopped Banana Fibers (6-12mm length) 0.8% Reinforcement, flexural strength
Sodium Silicate (Na₂SiO₃) 3.2% Silica source, improves strength
Sodium Hydroxide (NaOH, 10M) 2.2% Activator

Properties

  • Initial Setting Time: 50-65 minutes
  • Yield Stress: 1.8-2.2 kPa
  • Structural Build-up Rate: 0.6-0.8 kPa/min
  • 28-day Compressive Strength: 32-38 MPa
  • Flexural Strength: 25-30% higher than base recipe
  • Crack Resistance: Significantly improved
  • Carbon Footprint Reduction: 82-87%

Recommended Applications

Ideal for decorative elements, complex geometries, and applications requiring enhanced toughness and crack resistance.

Bio-Enhanced Hybrid Binder Mortar

Composition

Component Percentage by Weight Function
Ground Granulated Blast Furnace Slag (GGBFS) 50% Primary aluminosilicate precursor
Desert Dune Fines (DDF) 20% Secondary precursor, improves density
Crushed Seashells (≤5mm) 15% Calcium source, partial aggregate
Modified Starch 5% Bio-binder, improves workability
Chopped Palm Fibers (6-12mm length) 0.5% Reinforcement, crack resistance
Chopped Banana Fibers (6-12mm length) 0.5% Reinforcement, flexural strength
Sodium Silicate (Na₂SiO₃) 5% Silica source, improves strength
Sodium Hydroxide (NaOH, 8M) 4% Activator

Properties

  • Initial Setting Time: 40-55 minutes
  • Yield Stress: 1.2-1.8 kPa
  • Structural Build-up Rate: 0.4-0.6 kPa/min
  • 28-day Compressive Strength: 28-34 MPa
  • Thermal Conductivity: 0.4-0.6 W/m·K
  • Breathability: Excellent
  • Carbon Footprint Reduction: 85-90%

Recommended Applications

Best for interior walls, thermal insulation applications, and where breathability and moisture regulation are important.

Anti-Bacterial Mortar with Natural Additives

Composition

Component Percentage by Weight Function
Ground Granulated Blast Furnace Slag (GGBFS) 55% Primary aluminosilicate precursor
Desert Dune Fines (DDF) 20% Secondary precursor, improves density
Crushed Seashells (≤5mm) 15% Calcium source, partial aggregate
Neem Extract 1% Anti-bacterial, anti-parasitic properties
Coconut Shell Ash 3% Pozzolanic material, anti-bacterial
Chopped Palm Fibers (6-12mm length) 0.6% Reinforcement, crack resistance
Sodium Silicate (Na₂SiO₃) 3% Silica source, improves strength
Sodium Hydroxide (NaOH, 10M) 2.4% Activator

Properties

  • Initial Setting Time: 45-60 minutes
  • Yield Stress: 1.6-2.1 kPa
  • Structural Build-up Rate: 0.5-0.7 kPa/min
  • 28-day Compressive Strength: 30-36 MPa
  • Anti-bacterial Properties: Effective against common mold and bacteria
  • Anti-parasitic Properties: Resistant to termites and other pests
  • Carbon Footprint Reduction: 80-85%

Recommended Applications

Ideal for humid areas, bathrooms, kitchens, and applications where resistance to microbial growth is important.

Implementation Guidelines

Material Processing

  • Desert Dune Fines: Grind to particle size <150 μm
  • Seashells: Clean, dry, crush, and sieve to <5mm
  • Plant Fibers: Cut to 6-12mm length, treat with 0.173% Ca(OH)₂ solution for 24 hours
  • Activator: Prepare 8-10M NaOH solution 24 hours in advance

Mixing Procedure

  1. Mix dry components thoroughly for 2-3 minutes
  2. Add fibers gradually while mixing to ensure uniform distribution
  3. Add activator solution gradually to dry mix while mixing
  4. Continue mixing for 5-10 minutes (depending on formulation)
  5. For bio-enhanced mix, prepare starch separately by heating with water

3D Printing Parameters

  • Nozzle Diameter: 15-25 mm
  • Print Speed: 50-80 mm/s
  • Layer Height: 10-15 mm
  • Layer Width: 20-30 mm
  • Time Gap Between Layers: 1-3 minutes (depending on recipe)

Curing Process

  • Protect printed structure from direct sunlight for first 24 hours
  • Maintain ambient humidity (UAE climate is suitable)
  • Allow minimum 7 days curing before applying loads
  • For optimal strength development, allow 28 days curing

Performance Evaluation

Mechanical Properties

Sustainability Metrics

Comparative Analysis

Property Base Geopolymer Fiber-Reinforced Bio-Enhanced Anti-Bacterial Portland Cement
Compressive Strength (MPa) 35-40 32-38 28-34 30-36 40-45
Flexural Strength (MPa) 4-6 6-8 5-7 5-7 4-5
Thermal Conductivity (W/m·K) 0.6-0.8 0.5-0.7 0.4-0.6 0.5-0.7 1.0-1.5
CO₂ Emissions (kg CO₂/ton) 150-200 140-190 120-170 145-195 800-900
Water Absorption (%) <10 <12 <15 <12 <8
Breathability Moderate Good Excellent Good Poor
Anti-Bacterial Properties Limited Moderate Moderate Excellent None

Download Detailed Documentation

Complete Research Report

Comprehensive documentation of all research, analysis, and findings

Recipe Formulations

Detailed recipes with mixing ratios and expected properties

Implementation Guide

Step-by-step instructions for material processing, mixing, and 3D printing

Performance Evaluation

Detailed analysis of mechanical properties, sustainability metrics, and comparative performance