Stability Evaluation Of N-Sodium Silicate Chemical Grouts by Means of Rheology and Syneresis Testing-PPT Presentation

PPT Presentation

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The presentation evaluates the stability of N-sodium silicate grouts using rheological testing and syneresis measurements. Two grout mixes were prepared with sodium silicate, water, dibasic ester, Tergitol NP-9, and either 12.5% or 8% vinegar. ASTM C778 graded sand was used for permeation tests.<br /><br />Conventional grout gel time can be assessed by observing when grout stops flowing or by measuring viscosity until it reaches 100 mPa·s. The study also used an Anton Paar Physica MCR 301 rheometer to examine grout behavior under controlled shear. The presentation emphasizes that advanced rheological analysis can detect changes in gelation that may not be apparent from visual observations or simple viscosity measurements.<br /><br />For syneresis testing, grout was permeated through sand columns. Specimens were measured over time, with mass and dimensions tracked for up to 250 days. The mass-loss data were evaluated relative to initial mass and specimen surface area. When results were averaged, the mass-loss trend was bilinear, indicating a change in the rate of loss over time, similar to the response observed for grout alone.<br /><br />The key conclusion is that testing grout by itself is useful but does not fully represent its behavior in soil. Mass loss from grouted sand depends strongly on the soil’s specific surface area and on specimen dimensions. Therefore, percentage mass loss alone can be misleading unless specimens have identical dimensions; geometry and surface area should be considered when interpreting syneresis results.

Keywords

N-sodium silicate grout

rheological testing

syneresis

gel time

viscosity

Anton Paar MCR 301

permeation tests

ASTM C778 graded sand

mass loss

specific surface area