The suspension that can be happen with traditional cements are often too viscous and too prone to sedimentation. Microfine hydraulic binders, made up of the same basic, inorganic and non-toxic matrix as traditional cements, differ in their much greater fineness.
They are in fact made up of granules which, depending on the type of microcement, have dimensions between 0.1 ÷ 10 μm those with more thrust fineness and within 0.1 ÷ 25 μm for those with less thrust fineness offering specific surfaces between 8,000 ÷ 15,000 cm2/g.
Grain size characteristics
From the granulometric point of view the microfine binders are often identified by means of two characteristic dimensions: the maximum characteristic dimension (D98) and the average characteristic dimension (D50). The maximum characteristic dimension D98 is the dimension in mm below which is 98% of the binder, so also the average characteristic dimension D50 is the dimension in mm below which is 50% of the binder.
What is most interesting in microfine cements is the maximum size of the grains that compose them as it is precisely this dimension that, having to be reasonably lower than the minimum width of the pores of the system to permeate, limits its injectability, which necessitates Inspection Camera Rental.
From a purely granulometric point of view, in fact, the injectability of a dispersion of micro-fibers through a sandy soil is conditioned both by the maximum size of the binder particles and by the minimum size of the sand grains.
Theoretical considerations of a geometric nature, supported by laboratory experiences, lead to the need to comply with the following dimensional requirement: D95 ‘≤ 0.08 D5’ s where D95 ‘is the dimension in mm below which is 95% of the binder; D5’s is the dimension in mm below which is 5% of the sand.
This relationship limits the maximum size of the ligand particles (detected by Inspection Camera Rental) as a function of the minimum size of the sand grains (represented by D5 ‘s) which are those that generate the pores of smaller diameter.Eg a sandy soil characterized by D5’s = 120 μm can be injected only with binder suspensions having D95 ‘<0.08 120 um, ie <9.6 μm.
Respect for the aforementioned granulometric requirement, however, provides only the potential capacity of a dispersion to permeate through the porous system and therefore may not be sufficient to guarantee its real intrusion. In addition, in fact, it is required that the viscosity of the dispersion be sufficiently low to avoid having to use too high injection pressures, such as to mechanically damage the system to be consolidated.
Furthermore, it is necessary that the granulometric requirement be satisfied even in a dispersed phase, that is, that there is not a noticeable swelling of the single particles or their agglutination when they come into contact with water.