Flow and granular analysis of cement paste with Nano-silica (nS): from macro to nano concrete design

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(1)Flow and granular analysis of cement paste with nano-silica Subject Concrete is the most widely produced man-made material. Current micro-silica (mS) is only applied in special cases, due to its high price, and nano-silica (nS) is not used in practice yet. The new nano-silica can be produced in such quantities and for low prices that mass application in concrete is within reach. reach It may replace cement in the mix, which is the most costly component and having also the largest environmental footprint. Goals The aim of this research is to create a practical application method and a model to apply newly developed nS in concrete and other granular building materials.. Figure 3. Hägermann cone based on EN 1015-3.. Figure 5. Mini spread flow test results for one commercial nano-silica sample.. Figure 1. a) Ingredients of a number of building materials, including their particle size and specific surface area, based on Brouwers (2010).. Figure 2. Accumulative particle size distribution (PSD) of all materials used in a mix and the PSD of the mix (dashed line) composed with the help of the mix design tool. The target function (solid line) is also shown (Hunger, 2008).. Figure 4. Example of a spread flow measurement. Figure 6. 6 Minimum water demand mortars (250 mm spread flow diameter).. Expected results. The use of nanonano-silica makes the produced concrete financially more attractive and reduces the CO2 footprint of the produced concrete products products.. The nano--silica will also increase the product properties of nano the concrete concrete:: the workability and the properties in hardened state, enabling the development of high performance concretes for extreme constructions constructions.. That means that a concrete with better performance, lower costs and an improved ecological footprint is designed.. The application of these concretes can be designed anywhere, both in infrastructure and in buildings buildings... of. Figure 7. Average water film thickness of nano-silica samples. Nano. 24.8 nm. Micro Figure 8. Target lines and optimum composed mix computed from the optimization algorithm for cement paste with CnS-2 (3% bwoc) and q=0.55 (dmax= 60.3 μm and dmin=0.079 μm).. Researcher. George Quercia/ g.quercia@tue.nl g quercia@tue nl / +31 40 247 2323. Supervisor. Jos Brouwers and Götz Hüsken/ jos.brouwers@tue.nl / +31 40 247 2930. Program/Subprogram Application of nano silica in concrete / M2i research M.81.1.09338 Host University. Eindhoven University of Technology/ Architecture, Building and Planning.

(2) Flow and granular analysis of cement pastes with nano-silica From macro to nano level concrete design. George Quercia, Jos Brouwers, Götz Hüsken. Eindhoven University of Technology, Department of Architecture, Building and Planning, Unit Building Physics and System, Eindhoven, The Netherlands, g.quercia@tue.nl. Subject Current micro-silica is only applied in special cases, due to its high price, and nano-silica is not used in practice yet. The new nano-silica can be produced in such quantities and for low prices that mass application in concrete is within reach. It may replace cement in the mix, which is the most costly and environmentally unfriendly component in concrete. Goals The aim of this research is to create a practical application method and a model to apply newly developed nS in concrete and other granular building materials. Research Question 1) Could be possible with a successful incorporation of nano- and micro-silica, both numerically and experimentally, replace 10 kg cement per kg added silica technically and economically?, 2) The mix design tool needs to be modified to account for particles with small sizes, whereby special effects may occur (surface effects, ζ-potential, agglomeration, etc.)? Strategy In the first instance materials characterization of the commercial nano-silica such SEM, STEM, EDS, LLS, DLS and others was carried out. Also different specific surface area determinations were performed (computed spheres based and BET internal and external surface). After the characterization of the physic-chemicals properties, nano-silica was combined with cement pastes to perform a mini spread flow test and regression analysis to compute their water demand (βp), water film thickness (δ) and deformation coefficients (Ep). The granular properties and particle packing of the mixes were analyzed using an optimization algorism and mix design tool based on (Hüsken, 2010) work. Expected Results The use of nano-silica makes the produced concrete financial more attractive and reduces the CO2 footprint of the produced concrete products. The nano-silica will also increase the product properties of the concrete: the workability and the properties in hardened state, enabling the development of high performance concretes for extreme constructions. Preferred Partners Applications / Sponsors This research was carried out under project number M81.1.09338 in the framework of the Research Program of the Materials innovation institute M2i and the user/sponsors of the Building Materials research group, in particular SELOR eeig Environmental Technologies and Geochem Research (EU 7th FP project). Prime Publication / Prototyping - Quercia, G., Brouwers, H.J.H. (2010). Application of nano-silica (nS) in concrete mixtures. In Gregor Fisher, Mette Geiker, Ole Hededal, Lisbeth Ottosen, Henrik Stang (Eds.), 8th fib International Ph.D. Symposium in Civil Engineering. (pp. 431-436). Lyngby, Denmark: DTU Byg. - Quercia, G., Brouwers, H.J.H. and Hüsken, G. (2011). Water layer thickness of silica fines and their effect on the workability of cement pastes. XIII ICCC International Congress on the Chemistry of Cement. Madrid 3 to 8 July, 2011. (Accepted).. Research Period February 2010 - February 2014 20-1-2011.

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