A Novel Menthol-Cementing Sampling Technique for Cohesionless Coarse-Grained Fillers

摘要

It is difficult to test the engineering properties of undisturbed cohesionless coarse-grained fillers in the laboratory, especially those with low water contents because most sampling methods disturb the natural structure of the filler. This study proposes a novel sampling method that uses menthol as a temporary cement to obtain samples that are more resistant to disturbance. Liquid menthol infiltrates the interparticle spaces and cements the particles together as it cools, forming a high-strength structure. The samples can then be cut with a cutting ring (for grain sizes ≤ 0.5 mm) or a cutting machine (for grain sizes ＞ 0.5 mm) to prepare the final samples, from which the menthol is removed by heating. To demonstrate the feasibility of the method, a number of laboratory experiments were performed, including sampling tests, confined compressive strength tests, vibration tests, drop tests, and CT scans. The optimal particle temperature for introducing the liquid menthol is 70℃, while 90℃ is optimal for removing the cemented menthol. For both cost and anti-disturbance reasons, 20°C is suggested as a suitable storage temperature for menthol-cemented samples. The interspace structure undergoes less change with increases in sample depth and with larger grain sizes. We recommend that the lower two-third of the depth of a menthol-cemented block is used as the final sample for laboratory testing.