Eyubhan Avci

UCS Properties of Superfine Cement–Grouted Sand

AbstractThis research focused on the strength characteristics of superfine cement–grouted sand with various gradations and relative densities. At first, grout properties of superfine cement suspensions were studied. The sedimentation and the setting time increased but the viscosity decreased as the water–cement (W/C) ratio increased. Additionally, the groutability of superfine cement suspensions with different W/C ratios into various graded sand specimens having different relative densities was tried. The groutability of suspensions especially into the fine sand specimens was successful with certain W/C ratios and increased as the W/C ratio increased but decreased as the relative density increased. Grouted sand samples remained in tanks filled with water at a temperature of 20°C until testing time and subjected to unconfined compressive strength (UCS) tests at different time intervals. The UCS of grouted sand specimens decreased as the W/C ratio increased, but it increased as the relative density increase...

Performance of Novel Chemical Grout in Treating Sands

AbstractA new chemical grouting formed by sodium silicate–boric acid mixtures was introduced. Initially, suitable sodium silicate and boric acid contents in the grout mixtures were studied. Gel tim...

Syneresis dependent shear strength parameters of sodium silicate grouted sands

The influence of syneresis on the shear strength parameters of both sodium silicate-formamide and sodium silicate-glyoxal grouted sands was investigated under wet-cured as well as air-dried conditions. Syneresis of sodium silicate-formamide and sodium silicate-glyoxal grout gels increased with the increase of sodium silicate content up to a certain point. After which, as the silicate content of both grout gels increased, their syneresis decreased. In general, syneresis of sodium silicate-glyoxal grout gels was higher than those of sodium silicate-formamide grout gels. Syneresis of sands injected by the above-mentioned grouts was also observed and found to be less compared to the related grout gels. Triaxial tests were run on both wet-cured and air-dried sand specimens at different time intervals to determine the effect of syneresis on the internal friction angle and cohesion intercept of grouted sands. Due to syneresis, the shear strength parameters of wet-cured sand specimens decreased with time to some extent and then ceased to have an effect. In contrast, the shear strength parameters of air-dried sand specimens increased with time up to a certain point, even though they underwent syneresis, and then became stable.

Permeability Characteristics of Sand Grouted with Glyoxal Blended Sodium Silicate

The goal of this study was to investigate the permeability characteristics of glyoxal blended sodium silicate injected sand specimens with different relative densities and gradations. Initially, rheological characteristics of glyoxal blended sodium silicate grouts were determined. Accordingly, the gel time decreased as the sodium silicate content increased. Viscosities of glyoxal blended sodium silicate grouts increased as the silicate content increased. Syneresis increased as the silicate content increased up to 37% but then started decreasing as the silicate content continued to increase. The groutability of glyoxal blended sodium silicate grouts into different graded sands specimens formed at various relative densities was highly successful. Grouted sand samples were kept in humidity room at a temperature of 20 °C till test time and put to permeability tests at different time intervals. In general, glyoxal blended sodium silicate grouting decreased the permeability of different graded sand specimens. The permeability of sodium silicateglyoxal grouted sand specimens increased with time as a conclusion of syneresis.

Syneresis effect on the permeability of chemically grouted sand

The aim of this research was to investigate the permeability of sodium silicate grouted sand specimens having various gradations and relative densities. Initially, rheological properties of sodium silicate grouts were studied. The gel time decreased as the sodium silicate content increased. Viscosities of sodium silicate grouts increased as the silicate content increased. Syneresis of sodium silicate grout gels increased with the increase of silicate content up to a point and then started decreasing sharply. The penetrability of chemical grouts with different sodium silicate contents into various graded sand specimens prepared at different relative densities was highly successful. Grouted sand samples were kept in humid conditions at a temperature of 20°C until testing time and were subjected to permeability tests at different time intervals. In general, sodium silicate grouting reduced the permeability of various graded sand specimens. The permeability of grouted sand specimens slightly increased with time as a result of syneresis.