Unconfined Compressive Strength of Compacted Disturbed Cement-Stabilized Soft Clay

Abstract

Pneumatic flow mixing method is a new land reclamation method, developed in Japan to meet the persistent lack of space. In this method dredged soft soil is mixed with a small amount of stabilizing material (such as cement) during transporting the soft soil in a pipe using compressed air to be used for land reclamation. In some cases, the soil/cement mixture is stored in temporary place for days and then transported and compacted at the required place. Basically, the cement chemical reaction starts immediately after the mixing with the soft soil and the mixture starts to gain its strength, therefore disturbing the mixture after days from the mixing influences the mixture strength. However, the soil/cement mixture is still able to gain extra strength after disturbance, transportation, and compaction. This study aims to evaluate the effect of dynamic compaction on the shear strength of disturbed cemented soft soil mixture experimentally. The mixture was fully disturbed after one week from mixing with cement. Three cement/soil ratios were used in this study under different dynamic compaction energies. Unconfined compression test was conducted at various curing times for both disturbed and non-disturbed specimens. Keywords Pneumatic flow mixing Á Stabilized soft clay Á Compaction Á Unconfined compressive strength Á Soil disturbance List of Symbols aw Cement ratio E 50 Modulus of deformation t Curing time q un Unconfined compressive strength q un_Non Unconfined compressive strength for nondisturbed cemented clay q un_Non_t Unconfined compressive strength for nondisturbed cemented clay at curing time t q un_D Unconfined compressive strength for disturbed cemented clay q un_D_T Unconfined compressive strength for disturbed cemented clay without compaction q un_D_T_t Unconfined compressive strength for disturbed cemented clay without compaction at curing time t q un_D_comp Unconfined compressive strength for compacted disturbed cemented clay q un_D_comp_t Unconfined compressive strength for compacted disturbed cemented clay at curing time i Increasing factor (i = q un_D_comp_t / q un_D_T_28) G s Average specific gravity for the specimen c w Water unit weight c t Total unit weight after curing c d Dry unit weight after curing e Void ratio after curing time R 2 Coefficient of determination

Evaluation of the Improvement Effect of Limestone Powder Waste in the Stabilization of Swelling Clayey Soil

“…This is in line with the general trends found in previous works [48,49], where an increase in the E 50 modulus was observed when the UCS increased. According to Ayeldeen et al [50], E 50 can be estimated for disturbed cement-stabilized soft clay as between 25 to 50 times UCS. Other authors increase this value to between 50 to 150 times [51].…”

“…Ayeldeen et al [50] reported that undisturbed cement-stabilized clay, with higher ratios E 50 /UCS, up to 160, shown brittle behavior with a clear peak. Nevertheless, re-molded samples with lower ratios have shown a ductile strain-stress behavior without a clear peak.…”

Assessment for Sustainable Use of Quarry Fines as Pavement Construction Materials: Part II-Stabilization and Characterization of Quarry Fine Materials

“…For quarry fines stabilized with Ecolan and fly ash-based stabilizers (with activator), the coefficients are of 72 to 468 × UCS and of 35 to 179 × UCS respectively. The multiplier coefficients of Ecolan-stabilized quarry fines are higher than the typical coefficients of undisturbed cemented clays from 50 to 300 [37], while the fly ash-stabilized quarry fines have similar coefficients to undisturbed cemented clays.…”

Stiffness of artificially cemented sands: insight on characterisation through empirical power relationships

“…This particular test has also been frequently used in many experimental programmes reported in the literature (e.g. Consoli et al 2012;Kaniraj and Havanagi, 1999;Ayeldeen et al 2016;Yi et al 2014) in order to verify the effectiveness of the soil stabilisation with cement, or to explore the relative importance of the factors controlling the stiffness of the cemented soils.…”