Can Celitement only be used by itself or can it be combined with familiar cement interground additives?

Celitements can be combined with all known cement interground additives. This means that “composite Celitements”, still with an improved CO2 balance, are also possible. In fact, we can see a great opportunity here as the very high specific rate of formation of C-S-H from Celitements could be helpful in the implementation of a “more with less” strategy in concrete construction. However, it must be borne in mind that under some circumstances the amount of calcium hydroxide available for a pozzolanic reaction is sometimes lower with Celitement.

Do concretes and mortars made with Celitement differ in look and feel from those made with Portland cement?

It is possible to produce virtually pore-free, finely structured and very smooth surfaces with Celitement. Because of the light colour we can also see potential uses in areas that until now have be reserved for high-grade white cements, i.e. a concrete made with Celitement hardly differs in look and feel from that made with white cement.

Does Celitement actually have any disadvantages?

Like everything in life, Celitement does not, of course, just have advantages. There are aspects which, at the very least, complicate the entry of Celitements, and also of virtually all other alternative binding agent systems, into the market. Alongside the material aspects, which must be examined in detail, these are building legislation, normative and unfortunately also psychological disadvantages. There is still no long-term experience that has been verified in practice and relates to the durability of buildings built with Celitement. We have, to be sure, applied the relevant test methods for durability tests on concrete and achieved thoroughly satisfactory results but these are just “artificial” rapid test methods. Because of the newness of Celitement we cannot yet demonstrate a building history (50 years is the usual design period for normal buildings). This is a problem with the rather conservative and risk-averse building sector. The dimensioning and design factors used by the planners and structural engineers for concrete structures are also based on empirical factors and coefficients determined over decades, or sometimes centuries, with “classical” concrete mix formulations. Any new binding agent, including Celitement, must therefore first prove in tedious test series that the known design factors for classical concretes can also be applied to the use of Celitement. This is actually not a problem. The end product of the hydration of Celitement is ultimately the C-S-H phase that is sufficiently familiar from Portland cement, i.e. the well-known “glue” in concrete. However, these proofs are labour-intensive and cost a great deal of time and money. The development of completely new building materials systems therefore also takes a comparatively long time. This can, perhaps, be compared with new drugs. Here again, tedious clinical studies are needed after a successful laboratory and research phase to provide statistically safe proof of the compatibility of a new active ingredient. With drugs there is also a comparable period of 10-12 years, from the active ingredient to medicines that are ready for sale, until they are available on the market.

From what raw materials is Celitement produced?

At present we produce Celitement from calcium hydroxide and sand although in principle other reactive raw materials could also be in the autoclave process. Even calcium-rich residues or recycled material from the production of concrete and aerated concrete are possible raw materials. However, we are starting with rather pure, i.e. uncomplicated, raw materials so that the system does not become unnecessarily complex at first and to ensure that the initial product batches are uniform and of good quality. We feel that first of all the quality has to be right. With growing experience, especially from the operation of an industrial plant, it will then in the future also be possible to use cheaper and alternative raw material policies. However, at the start we will continue to confine ourselves to lime and sand. The “top down” principle already mentioned in other answers also applies here.

What advantages does Celitement have over classical Portland cement?

This answer to this question can be found on our homepage under “THE PRODUCT” and the sub-heading “SUMMARY OF ADVANTAGES”.

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