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Archive for September, 2011

Abstract
High strength geopolymers were produced from coal combustion fly ashes. These matrices reached compressive strength values over 100 MPa, much stronger and denser than obtained by using Portland Cement binders. Size fractions were obtained by size separation techniques and the relationship between strength and particle size was investigated. The differences in compressive strength measured in the geopolymers made from fine fractions, the original fly ash and a coarse fraction of the same ash, were not significantly higher than the variation found for a reference geopolymer material. Therefore, a direct size-strength relationship could not be proven. Moreover, the chemistry and the pH of the fractions also varied, and this might as well has played a role in the strength development.

Source: High Strength Geopolymers Produced From Coal Combustion Fly Ash

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World-wide Increase in Geopolymer Research

World-wide Increase in Geopolymer Research


Twenty five years long, geopolymer science was studied in very few laboratories and institutions. It is only during the last five years that we notice a strong increase in geopolymer research. The number of scientific papers dealing with geopolymer science & technology is following an exponential growth. The chart displays the evolution of the number of geopolymer papers published from 1991 onwards (publication of Davidovits’ reference paper in J. Thermal Analysis), up to 2009, referenced in Science Direct + SpringerLink under the keyword “geopolymer”.

Source: Geopolymer Institute

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Large size can replace almost 11 bricks with a single block

Large size can replace almost 11 bricks with a single block


Pouring lightweight concrete over radiant floor heat system

Pouring lightweight concrete over radiant floor heat system


Note: you can use recycled ground styrofoam known as ‘regrind’.

Cellular lightweight concrete (CLC) is a version of lightweight concrete that is produced like normal concrete under ambient conditions. It is produced by initially making a slurry of Cement +Sand + Fly Ash (constituting 26% – 34 % content) + water, which is further mixed with the addition of pre-formed stable foam in an ordinary concrete mixer under ambient conditions. The mixture is either poured or pumped into assembled moulds of blocks or form-work of reinforced structural elements or poured onto flat roofs or voids for thermal insulation or filling. The foam imparts free flowing characteristics to this slurry due to ball bearing effect of foam bubbles enabling it to easily flow into all corners and compact by itself in the moulds/forms without requiring any kind of vibration or compaction.

This Cellular Lightweight Concrete (CLC) can be produced in a wide range of densities from 400 kg/m3 to 1,800 kg/m3 to suit different applications: –

– The lower densities of 400 –600 kg/m3 are ideal for thermal insulation applications. CLC’s fire, termite, waterproofness and environment friendliness make it a far superior alternative to the commonly used Thermocole, glasswool, woodwool etc.

– The density range 800-1000 kg/m3 is utilized for making pre-cast blocks (~500x250x200/100 mm) for non-load-bearing walling masonry in framed structures.

– The CLC range from 1200kg/m3 (Crushing strength 65 kg/cm2) to 1800 kg/m3 (Crushing strength 250 kg/cm2) is structural grade material utilized for:

(a) In-situ casting of structural (load-bearing) walls and roofs of low rise individual or group housing schemes. or

(b) Manufacture of reinforced structural cladding or partitioning panels. Or for

(c) Making pre-cast blocks (~500x250x200/100 mm) for load-bearing walling masonry for low-rise buildings.

Source: System Building
Image source: LightCrete

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Incorrect mix, aggregate segregation and the mortar displaced towards the surface

Incorrect mix, aggregate segregation and the mortar displaced towards the surface


Correctly composed mix, uniform distribution of the aggregate

Correctly composed mix, uniform distribution of the aggregate


The exposure of aluminosilicate bodies of the type cement clinker, slag, fly ash or thermally activated substances to very alkaline environments (hydroxides, silicates) gives rise to the formation of new materials – geopolymers characterized by a two- to three-dimensional Si-O-Al structure. Substantial attention has been given to these new materials, for instance, at symposia or in papers mentioned in databases. Such contributions deal not only with the results obtained during the investigation into the synthesis of geopolymers and their microstructure (by using predominantly SEM) but also with their possible applications particularly in conjunction with the valorization of inorganic rejects (first of all, fly ashes).

The above contributions pay special attention to the polymer character of the geopolymer (solid phase NMR), to its mechanical properties and to the effect of aggressive (corrosive) environments as well as to its leaching behavior, etc. There are only few published data dealing with the properties of concretes on the basis of geopolymers. Therefore, the present paper deals with the investigation into the properties of the concretes on the basis of geopolymers.

Source: Concrete Based on Fly Ash Geopolymers

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Jewels 4 Pools Geo Polymer is a specifically designed polymer additive for pool renders especially those containing glass

Jewels 4 Pools Geo Polymer is a specifically designed polymer additive for pool renders especially those containing glass


Finished pool by Jewels 4 Pools

Finished pool by Jewels 4 Pools

The application of JEWELS 4 POOLS as a render is as simple as it gets. The application can be carried out by any competent applicator and the method is no different from that of any other STD exposed aggregate plaster finish.

As a general rule the crystal is mixed with pure white or off white cements at a ratio of 2 parts aggregate to 1 part cement.

Geo polymer is added at 500mls per 20 kg of cement.
The addition of Geo Polymer will greatly improve the workability of the plaster.
Reduce the water cement ratio resulting in little or no shrinkage in the most extreme conditions.
Adhesion is significantly improved with a greatly reduced risk of delaminating or blow out.
Geo Polymer is a highly modified polymer additive and is only available through Jewels4pools
Geo Polymer is not a setting agent.
Geo Polymer has been trialed for 6 years with 100% glass applications.

Always use a tarpaulin to provide protection from direct sun and adverse conditions during application. Application can either be by hand or machine. Suitable for new pools and renovations.

Source: Jewels 4 Pools

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Abstract
This paper presents the initiative and progress of the research on making geopolymer concrete using the Sarawak fly ash at Curtin University Sarawak Campus Malaysia. The author recently initiated the project of making geopolymer concrete using the fly ash produced by the coal-fired power plants at Kuching, Sarawak. The project aims at making and studying the different properties of geopolymer concrete using this fly ash and the other ingredients locally available in Malaysia. The very limited results available at this stage of the study show that the physical properties and chemical composition of the Sarawak Fly Ash is favorable to make high strength geopolymer concrete. However, the actual compressive strength of the concrete depends on various parameters such as the ratio of the activator solution to fly ash, molarity of the alkaline solution, ratio of the activator chemicals, curing temperature etc. Some observations in making geopolymer concrete in the laboratory using the Sarawak fly ash are also discussed.

Source: Strength of Geopolymer Concrete Using Sarawak Fly Ash

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Earth House Estate Lattenstrasse, Dietikon, Switzerland

Earth House Estate Lattenstrasse, Dietikon, Switzerland


Earth House Estate Lattenstrasse, Dietikon, Switzerland

Earth House Estate Lattenstrasse, Dietikon, Switzerland


Earthbags or tubes can be used to cast or form stone arches without Portland cement. This new, exciting building method combines earthbag building with geopolymer and ferrocement. Applications include vaults, and arches over doors and windows. As with anything new, you’ll need to refine the design, test materials and gain experience.

Image source: RobAid

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