Understanding the Filler Effect on the Nucleation and Growth of C‐S‐H

Abstract

The "filler effect", due to the physical presence of mineral additions in cement, is mainly known to accelerate the hydration of the clinker component. Previously, this was attributed to the surface of the filler providing nucleation sites for C-S-H as there is a clear dependence on the surface provided by the filler particles. Our results reveal that the increase in nucleation is quite low compared to the area provided. Based on the isothermal calorimetry experiments and SEM images, we demonstrate that the most important parameter is the interparticle distance. We propose that this is mainly the result of the shearing conditions rather than extra surface available for C-S-H as formerly assumed. Quantitatively slag and fly ash behave very similarly to quartz. Limestone, on the other hand, seems also to stimulate C-S-H nucleation giving it a higher efficiency in accelerating clinker hydration.

TC 238-SCM: hydration and microstructure of concrete with SCMs

“…Methods based on continuous weighing also exist although these can usually only measure one sample at a time, which together with the cost of an accurate balance, makes the methods more expensive. Figure 21 shows chemical shrinkage data for slag blends (including repetitions) collected over 4 months by Berodier [9,10]. This illustrates that reasonably reproducible measurements can be obtained.…”

“…Before going further, it is important to clarify what is the so-called filler effect, which was studied by, for example, Gutteridge and Dalziel [35]; Cyr et al [18]; Berodier and Scrivener [9,10] where the simple physical presence of an SCM (or even an inert material) will impact the reaction of the clinker phases. This effect has two components:…”

“…(b) The second effect is that the surfaces of the SCM may act as nucleation sites for hydrates. Berodier [9] showed that this effect is relatively minor for SCMs with a similar particle size distribution to that of Portland cement, but it can be important for fine materials such as silica fume, which has a significant acceleration effect on the hydration of the clinker (e.g. [35,36], Rossen [62].…”

Evolution of pore structure in blended systems

“…The chemical compositions by XRF are given in Table 1 and the phase compositions are shown in Table 2. All the powders have close particle size distributions to provide similar filler effects [24] (Fig. 1).…”

Estudio de las reacciones de hidratación temprana en el hormigón proyectado

“…En particular, el método de estudio se ha aplicado para comparar el mezclado manual con la proyección así como analizar el "efecto filler" de la adición de caliza ultra fina, es decir, la aceleración de la hidratación del cemento debida a la presencia de la caliza [10][11][12][13][14].…”