Effects of specimen thickness on apparent swelling pressure evolution of compacted bentonite

With the interests to see specimen thickness (h(sp)) effect on apparent swelling pressure (p(s)) of compacted bentonite and capture characteristics of p(s) development during wetting bentonite specimens (p(s) evolution, hereafter), a series of tests to measure p(s) of compacted bentonite specimens with a dry density (rho(d)) range of 0.99-1.76 Mg/m(3) and a specimen thickness (h(sp)) range of 2-10 mm were conducted. Test results suggest: (1) ps evolution generally has common characteristics with four feature points chronologically: peak (t(p), p(p)), valley (t(v), p(v)), initial equilibrium (t(ei), p(ei)) and an equilibrium (t(eq), p(eq)), where, t(p), t(v), t(ei) and teq represent time (t) and p(p), p(v), p(ei), and p(eq) denote p(s) of the four feature points, respectively; (2) within the tested range, h(sp) effect is generally minor on p(s) at feature points, and p(p), p(v), p(ei), and p(eq) have well correlations with specimen final dry density (rho(df)); (3) time scale for specimens with different hsp can be well unified by a time coefficient chi(sp) (-h(sp)/root t). (C) 2022 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society.