An investigation of particle breakage in loess

The paper presents a detailed experimental investigation of particle breakage in three kinds of loess, i.e., sandy loess, silty loess and clayey loess. It is firstly found that particle breakage can occur within loess in oedometer test, which results in a better-graded soil at the end of the test. Initial breakage stresses for both the silty and clayey loess are less than 0.5 MPa, and about 2 MPa for the sandy loess. The relative breakage (B_r) is used to evaluate the particle breakage degree, and it is found that for all the three kinds of loess tested, B_r increases with the increasing loading stress until it reaches a threshold, after which B_r tends to keep a constant value. Particles within the loose specimens break more easily than those within the dense ones, especially for the sandy and silty loess. It is also observed that for the specimens reconstituted with previously tested soils, particle breakage degree decreases significantly, which means little particle breakage occurs in the pre-crushed specimens.