List for the tag keyword: cement
Materials for the Third Millennium
Think Geopolymer and Geosynthesis!
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 [...]
There is often confusion between the meaning of the terms “cement” and “concrete”. A cement is a binder whereas concrete is the composite material resulting from the addition of cement to stone aggregates. Cement is sold to companies that make concrete.
Geopolymer cement is often mixed up with alkali-activated slag developed since 1956 in Eastern Europe [...]
Up to 90% reduction of CO2 Greenhouse Gas emission during cement manufacture
Professor J. Davidovits started working on CO2 emissions mitigation as earlier as 1990, at PennState Materials Research Laboratory, USA. American Agencies (DOE and EPA) stated that this was not an important issue and both institutions declined to support research proposals.
In this section we develop:
a) [...]
GEOpolymeric Cements for Innocuous
Stabilisation of Toxic EleMents
Geosynthesis of Rock-based Geopolymer cements was the objective of the European multidisciplinary BriteEuram industrial research project GEOCISTEM. The project titled cost effective GEOpolymeric Cements for Innocuous Stabilization of Toxic EleMents, in short GEOCISTEM, started on Jan. 1994 and has been completed on June 1997.
In J. Davidovits’ book, Geopolymer Chemistry [...]
Geopolymer combines the merits of cement and ceramics, we can make materials with the properties of ceramics by a process like cement. Water reducing agents are popular in cement industry.
The question is what will happen in geopolymer?
Experiences carried out with geopolymer cements show good results with regular water reducing agents used for Portland Cement. The [...]
My name is Prof. Mario Collepardi and I am a professor of “Materials Science and Technology” at the Politecnico of Milan, Italy. Yesterday I have seen your interview by Mr. Giacobbo at the “Stargate” program on “La 7″ Italian TV channel. I am very interested to your theory about the building technique used by Egyptians [...]
Long-Term Stability of Geopolymeric Materials
The task LONGTERM in the GEOCISTEM project dealt with the better understanding of long-term durability. It is difficult to predict extended durability on the basis of operating experience, laboratory experimentation and prototype testing. Two thousand years are generally accepted as a sufficient amount of time to permit decay of [...]
The atomic ratio Si:Al in the poly(sialate) structure determines the properties and application fields. A low ratio Si:Al (1,2,3) initiates a 3D-Network that is very rigid. A high ratio Si:Al, higher than 15, provides polymeric character to the geopolymeric material. One third of Davidovits’ book, GEOPOLYMER Chemistry & Applications, is dedicated to applications. See the [...]
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 [...]
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 [...]
