Having more resistant to chemicals and the ability to withstand high temperature, researchers at TU Darmstadt recommended the use of ‘geopolymers’ instead of cement. Professor Eddie Koenders. Civil engineer and Head of the Institute of Construction and Building Materials at TU says, it is a promising alternative to cement as the characteristic advantage of ‘geopolymers’ is that it does not emit Carbon dioxide. A recent study has found out that more than 5% of carbon dioxide is emitted in the production of cement globally. The concrete building also has an adverse effect, releasing carbon dioxide more than air traffic.
History of origin
French chemist, Joseph Davidovits was the first one who introduced the term ‘geopolymers’ in the seventies. It was first used with metakaolin, though it does not contain carbon dioxide, but it consumed a lot of energy for its pre-thermal treatment. The material is very fine and sticky, when it comes in contact it sets quickly with the activation solution and it is different to working with cement paste.
The now ‘geopolymers’ is an inorganic polymer, where two molecular components are combined. It comprises of solid which contain silicon and Aluminium, found in natural stones or mineral and a basic activation solution of alkali hydroxides or alkali silicates in water. The prefix of the term ‘geopolymers’ is derived from the uses of natural stones and mineral
Though in earlier days it was not a popular material to use, but now it has created a growing need, giving new heights to researchers, as a result of the continual argument on climate. Koenders, who is working together with scientist and companies from Spain, France, Austria and UK in planning for an EU projects, says, “There is a great International interest”. He also stresses that “Geopolymers will only ever replace concrete and cement on a large scale if they have the same workability”
Methods are devices and different raw materials are tested to improve the quality and cost- efficiency. Metakaolin is replaced with natural stone trass, which is available at Eifel. Owing to its richness in alkalies, it has reduced the concentration of the alkaline activation solution, thereby reducing cost.
Dr. Neven Ukrainczyk, a chemical engineer working on molecular basis and physic- chemical analytics and Oliver Vogt, a civil engineer overseeing the practical application, have been contributing a lot in researching like finding new admixtures, re- designing of conventional superplasticizers. With them joining the TU Darmstadt in 2014, there is a possibility of setting it up a micro-laboratory to experiment the minute details of ‘geopolymers’. Different machines will be acquired, to facilitate the experiment of other construction materials; data are collected and put in records..
Geopolymers over cement
Though it is more expensive than conventional cement, Geopolymers has a lot of technical advantages. It is founded that it can endure more heat than concrete and have better resistant to chemicals, which eliminates the possibility of ‘Cracking and Spalling’. It is also time efficient, as it takes only one day to develop compressive strength and can also be de-molded quickly, making it possible to produce more prefabricated construction elements. Bidding on “durability” to justify its high price, Koenders says, “We are looking for solutions that are also economically interesting. We want to put geopolymers into practice as quickly as possible”. The TU Team is offering geopolymers sewer pipes that have better resistant to biochemical.
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