Low-Calcium Hydraulic Binding Agent
- The raw material base for Celitement is similar to that of Portland cement (in particular CaO, SiO2), but the composition shifts from high-calcium (see C3S, C2S, C3A) to high-silicon (hCHS).
- Celitements are relatively low-lime binding agents with minimal efflorescence tendency. The pore water used in hydration is low-lime and low-sulphate, with a minimal tendency to fuse.
- Due to the lack of formation of calcium hydroxide layers in the contact zones, Celitements form a cement stone matrix (C-S-H Phase) expected to have good coupling properties to fibres and reinforcing steel.
Enables High Quality Surfaces and Optics to be Achieved
- Very high degrees of whiteness and brightness values (L values) are possible in the final product without additional process cost. Brightness only depends on the quality (e.g. Fe-content) of the raw material base. Celitements therefore enable a high level of colour brilliance and an effective and economical use of colour pigments e.g. for coloured concrete goods.
- Celitements can be used to manufacture extremely high quality, fine structured and pore-free surfaces.
Demonstrates Entirely new combinations of cement Properties
- Celitements are the only binding agent with a decoupling of early strength formation and heat release. Despite their very low hydration heat development ( CEM I 42.5 R). This enables savings to be made in the construction process of bulky concrete components and savings on reinforcement otherwise needed avoid the formation of cracks.
- In the case of very high w/z values, Celitements enable the manufacture of a “nanoporous” C-S-H structure with low heat conductivity properties.
- As an “isochemical” binding agent, Celitements form an extremely good bond with classical cement surfaces in combination with traditional cements.
Simple and almost monophase Composition
- The simple and almost monophasic composition of Celitements simplifies the formulation of high-performance construction chemistry recipes.
Has special durability proberties
- Due to the low water requirement, hydraulic calcium hydrosilicates (hCHS), Celitements form an extremely dense microstructure or pore structure. Water cement ratios are very low because the system already contains water (optimal w/z value <0.40). Celitements can therefore be used to manufacture highly durable components.
- Celitements do not contain any aluminium (e.g. C3A) or aluminoferritic (e.g. C4AF) phases. As pure C-S-H phases, Celitements therefore demonstrate an extremely high level of sulphate resistance. They do not possess any potential for damage as a result of the formation of phases such as secondary ettringite or thaumasite. They are ideal cement-based bonding bridges in combination with gypsum-bound construction systems.
- Since they are free from aluminates, Celitements demonstrate an almost unlimited opportunity for curing of prefabricated concrete parts. Harmful ettringite formation by curing is excluded due to the absence of gypsum and alumiates.
- Celitements can be manufactured with high specific surfaces (BET) or fineness, similar to e.g. microsilica, for example. They only need water to form C-S-H, though, while highly reactive fine silicon compounds also require a strongly alkaline environment and the presence of excess Portlandite Ca(OH)2. Celitements are therefore ideally suited to the manufacture of UHPC and other very high-performance fine concretes and mortars.
- Due to their special chemical and mineralogical properties, Celitement has an exceptionally good resistance to the so-called alkali-silica reaction (ASR). This damage mechanism particularly restricts the use of numerous aggregate qualities in concrete. Our results so far show that Celitement has excellent resistance to this damage mechanism, which is particularly relevant for concrete roadways.
Compatible with Portland cement in established applications and product groups
- Celitements can be fully mixed and combined with traditional cements and additives.
- Celitement is comparable with established mass construction materials in its main handling, transport and storage properties.
Can be produced around the globe with available raw materials and known technologies
- The equipment and process technologies used to manufacture Celitements are in principle known from established manufacturing processes for mass construction materials. The manufacturing processes represent a combination of know autoclave techniques from aerated concrete and sand-lime brick production and innovative dry grinding techniques from the manufacture of fine materials or high-performance cements.
- The main oxide necessary for Celitement production, namely CaO and SiO2, are part of the raw material mix traditionally used in Portland cement production. Already existing large production sites of the cement and lime industry, with their abundant raw material resources, are worldwide available for the production of Celitement.
Classic knowledge about C-S-H Phases can be used to optimise applications
- The end product C-S-H (the “glue” in concretes and mortars) formed when Celitement (hCHS) is hydrated is best known in terms of cement chemistry from traditional Portland cements. Lots of well-established practical knowledge of C-S-H can be adopted.
- Due to its special composition (“pre-hydrated binding agents”), Celitement only requires an extremely small amount of water to be added to form the “glue” C-S-H.
Advantageous ecological proberties in occupational and health protection
- Depending on the quality of the raw materials used, Celitements contain almost no soluble alkalis. They are in principle chromate-free and also do not contain any heavy metals.
- Celitement has a complete safety dossier from a successful REACH registration with the European chemicals agency ECHA, completed in 2018. The intricate tests show that Celitement is harmless under stringent European chemicals legislation.
- Unlike Portland cement, Celitements do not require a sulphate carrier. However, they can be combined with sulphates if special applications have that requirement.
- The relatively low pH of the pore solution, compared to Portland cement or geopolymer cements, offers certain advantages in occupational and health protection (e.g. modelling with cement/Celitement mortar).
- Celitement has a positive and innovative product and brand image and is licensed exclusively by Celitement GmbH & Co. KG.
Large Number of variants of an entire binding agent class
- Celitement is not a single product but rather forms an entire class of new, innovative, hydraulically active binding agents depending on the composition and slight variations in the manufacturing process. The properties of these Celitements, which may vary in composition and degree of activation, offer significant potential for optimisation in the future.
- The hardening and strength characteristics of different Celitements can be controlledover a wide range.