The last few years have seen spectacular technological progress in the development of geosynthesis and geopolymeric applications.

New state-of-the-art materials designed with the help of geopolymerisation reactions are opening up new applications and procedures, and transforming ideas that have been taken for granted in inorganic and mineral chemistry.

Since the discovery of the geopolymer chemistry by Prof. Joseph Davidovits (see also in the Library the scientific paper IUPAC 1976) this new generation of materials, whether used pure, with fillers or reinforced, is already finding applications in all fields of industry. These applications are to be found in the automotive and aerospace industries, non-ferrous foundries and metallurgy, civil engineering, cements and concretes, ceramics and plastics industries, waste management, art and decoration, retrofit of buildings, etc. One third of the recently updated book Geopolymer Chemistry & Applications is dedicated to geopolymeric applications. You may also go to the Geopolymer Library and download several papers, for example #21 Geopolymer cement review 2013.

Some of the geopolymer applications are still in development whereas others are already industrialized and commercialized. They will be listed in six (6) categories, namely:

Geopolymer Precursor

Geopolymer Resin, paint, binder, grout

Geopolymer cement, concrete, waste management, global warming

Applications with geopolymer cements and concretes are described in the section Geopolymer Cement with special emphasis on the introduction of user-friendly systems. It is striking to notice that Geopolymer cements manufacture emits 80 to 90% less CO₂ (greenhouse effect gas) than Portland Cement. See in GLOBAL WARMING. They are perfect examples of Green Chemistry and Sustainable Development.

For information on Fly Ash-based geopolymer cements go to European Research Project GEOASH. For updated very recent detailed information, read Chapters 12, 24, 25 in Geopolymer Chemistry & Applications; you may also download previous papers in the Library .

Rock-based geopolymer cements are ideal for environmental applications, such as the permanent encapsulation of radioactive and other hazardous wastes, toxic metals, as well as sealants, capping, barriers, and other structures necessary for remedying toxic waste containment sites (see our European Research Project GEOCISTEM and the GEOPOLYTECH process). See also in the Library .

Rock-based geopolymer cements and concretes for building and repairing infrastructure have very high early strength, their setting times can be entirely controlled, and they remain intact for a very long time without the need for repair. See in Davidovits’ book, Geopolymer Chemistry & Applications, the Chapters 9, 10, 24 and 25. The strength of geopolymeric rock-based geopolymer concrete is such that a heavy Boeing or Airbus can land on a runway freshly patched with geopolymeric rock-based geopolymer concrete only four hours after patching has been completed. The discovery of this new cement was awarded with a Gold Ribbon by the American National Association for Science, Technology and Society (NASTS) in 1994 (Library paper #3 NASTS award ).

Geopolymer specialty

Geopolymer ceramic

Several decades ago, ceramicists tried to manufacture ceramic tiles at temperatures lower than 450°C, without firing. Geopolymer science masters the transformation of kaolinite, the major component of ceramic clays, into geopolymers of the poly(sialate) and poly(sialate-siloxo) types. Application of this chemistry yielded several technological breakthroughs pertaining to LTGS, Low-Temperature-Geopolymeric-Setting and geopolymerized modern ceramic processing. See in Chapter 23 of Davidovits’ book Geopolymer Chemistry & Applications .

Geopolymer high-tech/ fiber reinforced composite

Geopolymer composites have three main properties that make them superior to ceramic-matrix composites, plastics, and organic composite materials.

First:
Geopolymers are very easy to make, as they handle easily and do not require high heat.
Second:
Geopolymeric composites have a higher heat tolerance than organic composites. Tests conducted on Geopolymer carbon-composites showed that they will not burn at all, no matter how many times ignition might be attempted.
Third:
The mechanical properties of Geopolymer composites are as good as those of organic composites. In addition, Geopolymers resist all organic solvents (and are only affected by strong hydrochloric acid).

Before the discovery of geopolymerization, these three critical properties had not been incorporated into any one material. More information are available in applications called GEO-COMPOSITE and GEO-STRUCTURE and in Davidovits’ book Geopolymer Chemistry & Applications , Chapter 21.

An Example of the Development of Geopolymeric Composites and Cements That Improves Air Travel Safety and Airport Efficiency*

The Chapters of the book GEOPOLYMER Chemistry & Applications dedicated to these applications are referred to in italic.

A jet is preparing for takeoff from a runway in New York as a crew begins placing a section of geopolymer concrete (Chapters 24, 25) on a Los Angeles runway. The plane is equipped with a fire-resistant geopolymer-encased electronic flight recorder. The jet’s cabin has also been rendered fireproof with sandwich panels of carbon/Geopolymite® composites (Chapter 21) and geopolymer foam insulating boards (Chapter 22). The jet is also equipped with a highly advanced fireproof air filter. Several structural components of the jet, made with an advanced SPF Al superplastic aluminum alloy, have been manufactured at 550°C using compression ceramic tools made of geopolymer materials (Chapter 20).

When the plane is ready to land in Los Angeles, the runway repaired with Pyrament® concrete will be ready for it.

*This fictitious example illustrates possible applications that are or have been manufactured and/or patented by several companies

Prof. Dr. Joseph Davidovits, Nov. 2011

Solid-Phase Synthesis of a Mineral Blockpolymer by Low Temperature Polycondensation

of Alumino-Silicate Polymers: Na-poly(sialate) or Na-PS and Characteristics .

Joseph DAVIDOVITS

INTRODUCTION

The work exposed here comes from an attempt to transfer our knowledge of organic polymers and the technologies associated with it to the yet unknown, or hardly known field of the synthesis and transformation of inorganic polymers, in order to develop new materials and new industrial processes. It is a matter of fact that inorganic materials like glass, ceramics, bricks, concrete, and most natural rocks by far outclass organic polymers with respect to their resistance to high temperature. This study provides an answer to the following question: Could we take mineral materials such as clay, kaolinite, that is to say aluminosilicate polymers, and transform them using the extreme low-temperature polymerisation technology of organic polymers ?”.The answer is : yes, we can. The resulting products have similar characteristics to natural rock‑forming minerals, such as zeolites, feldspathoids and feldspars. These different minerals are usually called silicates or aluminosilicates in the same way as kaolinite, clays, micas, mullite, andalusite, spinel, etc. that is in brief all the minerals whose empirical formula contains Si, AI, O, and any other elements such as H, Na, K, Ca, Mg, etc. For the development of our knowledge and for a better understanding of the mechanism of this new synthesis of inorganic polymers, we felt we had to introduce a more precise terminology.

Click here to see how to download paper nr 20.

The Federal Aviation Administration (F.A.A.), USA, has recently initiated a research program to develop low-cost, environmentally-friendly, fire resistant matrix materials for use in aircraft composites and cabin interior applications. The flammability requirement for new materials is that they withstand a 50 kW/m² incident heat flux characteristic of a fully developed aviation fuel fire penetrating a cabin opening, without propagating the fire into the cabin compartment. The goal of the program is to eliminate cabin fire as cause of death in aircraft accidents. However, voluntary adoption of the new materials technology by aircraft and cabin manufacturers requires that it be cost effective to install and use, so it is expected that these new aircraft materials will be broadly applicable in transportation and infrastructure where a high degree of intrinsic fine resistance is needed at low to moderate cost. To this end the F.A.A. is evaluating a new, low-cost, inorganic geopolymer matrix derived from the naturally occurring geological materials- silica and alumina. At irradiance levels of 50 kW/m² typical of the heat flux in a well developed fire, glass- or carbon-reinforced polyester, vinylester, epoxy, bismaleinide, cyanate ester, polyimide. phenolic, and engineering thermoplastic laminates ignited readily and released appreciable heat and smoke, while carbon-fiber reinforced geopolymer composites did not ignite, burn, or release any smoke even after extended heat esposure.

In the recently updated book Geopolymer Chemistry & Applications the fire and heat resistant composite applications are thoroughly outlined in Chapter 21. You may also go to the Geopolymer Library and download several papers..

Excerpt from the technical press
Performance Materials,
February 5, 1996, page 5.

As Hot as You Like It

Mechanical Properties are Looking Good for French Inorganic Polymer that Doesn’t Burn.

Fire safety is a concern often voiced by those who are skeptical about the use of composite materials in the infrastructure. These fears may be put to rest by a revolutionary European matrix material that doesn’t burn at all (PM, July 31, 1995). “Fire is going to be the limiting criterion in a lot of infrastructure applications C says Rich Lyon of the Federal Aviation Administration (FAA) Tech Center in Atlantic City. But his ICCI ‘96 presentation about the new family of inorganic polymer composites was almost anticlimactic. “It’s a fairly boring story because there is no fire response,” Lyon said in Tucson.

FAA Is Interested, Too

The inorganic polymeric materials are cheap, at about $2-3 a pound. They cure at low temperatures.
And now there is evidence that the new material family, trade named Geopolymer (or, more precisely, Géopolymère), boasts mechanical properties comparable to those of organic-matrix composites. FAA-supported testing was conducted at Rutgers University in New Jersey.
“The initial results are very encouraging: Prof. P (Bala) Balaguru of Rutgers said at the Tucson infrastructure meeting. Carbon-matrix composites made with the Geopolymer matrix demonstrated a strength of approximately 327 MPa (about 225 ksi), he said, quite comparable to organic composites. “The same thing is true for flex and shear;’ Balaguru said. The Rutgers test coupons were made using 3K, polyacrylonitrile-based carbon fiber that was manually impregnated and vacuum-bagged for curing in an 80°C (176°F) heated press. The samples were post-cured in an 80°C oven for 24 hours.
Experimenters have thus far made samples only via hand layup, and have been able to achieve fiber loadings of only 50 % (the Rutgers tests were conducted on 45-percent material). At least 60 % is expected when fabrication processes are refined, says the FAA’s Lyon. Problems with voids are also expected to be solved when better fabrication techniques are applied.
“These materials are in their infancy) FAA Lyon says. Geopolymer inventor Joseph Davidovits spent much of his career as a textile chemist and began pursuing inorganic polymers in part, he says, behind a tragedy in France in which the deaths by fire of more than 100 young night club patrons were attributed to fast-burning polyester curtains. Davidovits cites three key Geopolymer attributes his company says “make them superior to ceramics, plastics, and organic composite materials:” (Performance Materials, February 5, 1996).

The First Non-flammable fabric laminate for Aircraft cabin and cargo interiors, Géopolymère Composite was introduced on November 18, 1998, in Atlantic City, NJ, USA, at the International Aircraft Fire and Cabin Safety Research Conference sponsored by the Federal Aviation Administration. More details in Press Release (see page 3)

Predicted time to flashover in ISO 9705 corner/room fire test with various structural composites as wall materials

Press Release, November 20, 1998
The First Non-Flammable Material for Aircraft Cabin Safety presented at FAA.

Fire Safety Meeting in Atlantic City, New Jersey, USA

The First Non-flammable fabric laminate for Aircraft cabin and cargo interiors, Géopolymère Composite was introduced on November 18, 1998, in Atlantic City, NJ, USA, at the International Aircraft Fire and Cabin Safety Research Conference sponsored by the Federal Aviation Administration.

Current aircraft design utilizes several tons of combustible plastics for cabin interior components that includes the passenger compartment, cockpit and cargo compartments. This is a fire load comparable to the equivalent weight of aviation fuel. The recent introduction of fly-by-wire control system as well as the increase of electronics components on an aircraft (such as flat panel displays for TV, telephones and computers) represents a new, higher risk of electrical fires and the potentially tragic consequences of uncontained in-flight fires. The FAA is working to eliminate cabin fire as a cause of death in aircraft accidents. In the unusual event of an aircraft accident, there are only seconds for passengers to escape before toxic fumes and fire fill the cabin compartment.

The FAA flammability requirement for new materials is that they must withstand the 50-kw/m² incident heat flux characteristic of a fully developed aviation fuel fire that penetrates the cabin skin. The material must prevent propagation of the fire into the cabin compartment. The first material to withstand this arduous test is Géopolymère Composite developed by Professor Joseph Davidovits of the Geopolymer Institute in France. Géopolymère Composite is described as an inorganic polymer (a silico-aluminate polysialate polymer) derived from the naturally non-flammable occurring geological materials silica and alumina, hence the name Geopolymer or Géopolymère in French.

Since January 1994, the Federal Aviation Administration has conducted a research and evaluation program on carbon fiber reinforced Géopolymère Composite. Tests were carried out at the FAA Fire Research Section, FAA Technical Center, Atlantic City, NJ and at the Department of Civil Engineering, Rutgers, The State University of New Jersey, in collaboration with Prof. Davidovits’ French company, CORDI-Géopolymère SA, Saint-Quentin, France. The FAA experiments indicate that even after exposure to a severe fire environment (more than 1,500°F during several hours), the carbon fiber reinforced Géopolymère Composite retained 63 % of its original flexural strength of 245 Mpa (approximately 169 ksi). In comparison, all materials presently used in an aircraft, including aluminum sheets and parts, organic based laminate composites and plastics, actually burn and are destroyed when submitted to the same severe fire environment.
Aircraft operators and manufacturers are sensitive to cost and cost-effectiveness. Aircraft operators estimate that each pound of weight on a commercial aircraft costs between $100 to $300 in operating expenses over the service life of the aircraft. Consequently, fire safe materials for use in aircraft must be extremely lightweight. With its low density of 1.85, carbon fiber reinforced Géopolymère Composite is lighter than aluminum (density 2.70) and structural steel (density 7.86).

Technical Data Sheet for Geopolymeric cement type (Potassium, Calcium) – Poly(sialate-siloxo) / (K,Ca) – (Si-O-Al-O-Si-O-), Si:Al=2:1

Further details in Davidovits’ book, GEOPOLYMER Chemistry & Applications, Part III, Properties, Chapters 15 to 18, GEOCISTEM , GLOBAL WARMING, and also previous papers in the Geopolymer Library.

Tested on standard sand mortar prisms:

• setting: 10 hours at -20°C to 7-60 minutes at +20°C.
• shrinkage during setting: <0,05%, not measurable.
• compressive strength (uniaxial): > 90 MPa at 28 days (for high early strength formulation, 20 MPa after 4 hours).
• flexural strength: 10-15 MPa at 28 days (for high early strength 10 MPa after 24 hours).
• Young Modulus: > 2 GPa.
• freeze-thaw: mass loss < 0,1% (ASTM 4842), strength loss < 5% after 180 cycles.
• wet-dry: mass loss < 0,1% (ASTM 4843).
• pH: crushed and powdered, 11-11,5 after 5 minutes in deionized water (compared to Portland cement: 12 to 12,5, and granite: 11).
• leaching in water, after 180 days: K₂O < 0,015%.
• water absorption: < 3%, not related to permeability.
• hydraulic permeability: 10-10 m/s.
• Sulfuric acid, 10%: mass loss 0,1% per day.
• chlorhydric acid 5%: mass loss 1% per day.
• KOH 50%: mass loss 0,02% per day.
• ammoniac solution: no mass loss.
• sulfate solution: shrinkage 0,02% at 28 days.
• alkali-aggregate reaction: no expansion after 250 days, -0,01% (compared to Portland Cement with 1% Na₂O, +1,5%).
• linear expansion: < 5.10-6/K.
• heat conductivity: 0,2 to 0,4 W/Km.
• specific heat: 0,7 to 1,0 kJ/kg.
• electrical conductivity: strongly dependent on humidity.
• thermal stability:
  • mass loss < 5% up to 1000°C.
  • strength loss < 20% at 600°C, < 60% at 1000°C

Other values:

• D.T.A.: endothermic at 250°C (zeolitic water).
• MAS-NMR spectroscopy:
  • 29Si: SiQ₄, major resonance at -94,5 ± 3ppm.
  • 27Al: AlQ(4Si), major narrow resonance at 55 ± 3ppm.
• Energy consumption: SEC for cement 1230-1310 MJ/tonne (compared to Portland clinker 3500 MJ/tonne).
• CO₂ emission during manufacture: 0,180 t/tonne of cement (compared to Portland clinker 1,0 t/tonne).

The fire response of a potassium aluminosilicate matrix (GEOPOLYMER) carbon fiber composite was measured and the results compared to organic matrix composites being used for infrastructure and transportation applications. At irradiance levels of 50 kW/m2 typical of the heat flux in a well developed fire, glass- or carbon-reinforced polyester, vinylester, epoxy, bismaleimide, cyanate ester, polyimide, phenolic, and engineering thermoplastic laminates ignited readily and released appreciable heat and smoke, while carbon-fiber reinforced GEOPOLYMER composites did not ignite, burn, or release any smoke even after extended heat flux exposure. The GEOPOLYMER matrix carbon fiber composite retains sixty-three percent of its original 245 MPa flexural strength after a simulated large fire exposure.

Click here to see how you can download paper number 4.

This report presents the results of an experimental investigation of the behavior of reinforced concrete beams strengthened with carbon fiber fabrics and geopolymer. The primary objective of the investigation was to determine whether geopolymer can be used instead of organic polymers for fastening the carbon fabrics to concrete. Four reinforced concrete beams that were similar to the ones reinforced with carbon fabrics and organic adhesives were tested. The beams had 0, 2, 3 and 5 layers of unidirectional carbon fabrics attached at the tension face of the beams. The results indicate that geopolymer provides excellent adhesion both to concrete surface and in the interlaminar planes of fabrics. All three beams failed by tearing of fabrics. This is very significant because very few researchers report failure of beams with tearing of fabrics. The most common failure pattern reported in the literature is the failure by delamination of fabrics at the interface of concrete and fabrics. Hence it can be stated that geopolymer provides as good or better adhesion in comparison with organic polymers. In addition, geopolymer is fire resistant, does not degrade under UV light, and is chemically compatible with concrete. Therefore, the product can be successfully developed for use in the repair and retrofitting of concrete structures.

Click here to see how you can download paper number 2.

published in the journal “Fire and Materials”, USA, 1996

This paper presents the latest results on the properties of GEOPOLYMER/CARBON composite, namely: * viscosity,

• chemical reactivity,
• differential scanning calorimetry,
• thermogravimetric analyses,
• mechanical properties (inplane shear, interlaminar shear, warp tensile, flexure).

It further compares GEOPOLYMER/CARBON composite to organic matrix composites being used for infrastructure and transportation applications. At irradiance levels of 50 kW/m2 typical of the heat flux in a well developed fire, glass- or carbon-reinforced polyester, vinylester, epoxy, bismaleimide, cyanate ester, polyimide, phenolic, and engineering thermoplastic laminates ignited readily and released appreciable heat and smoke, while carbon-fiber reinforced GEOPOLYMER composites did not ignite, burn, or release any smoke even after extended heat flux exposure. The GEOPOLYMER matrix carbon fiber composite retains sixty-three percent of its original flexural strength after a simulated large fire exposure.

Click here to see how you can download paper number 1.