Humidity Effects and Aging Behavior in Granular Media

TL;DR

This study investigates how humidity influences the stability and aging of granular media, revealing that humidity affects the aging process and stability angles through capillary condensation mechanisms.

Contribution

It introduces a model explaining humidity-dependent aging in granular media based on activated capillary condensation, supported by experimental observations.

Findings

Aging of the avalanche angle increases logarithmically with resting time.

Higher humidity accelerates aging effects.

Capillary condensation explains humidity influence on stability.

Abstract

We present a study of humidity effects on the maximum stability angle in granular media. We show that a granular medium of small glass beads exhibits aging properties : the first avalanche angle increases logarithmically with the resting time of the pile. This aging behavior is found to depend on the relative humidity of the surrounding atmosphere. A short interpretation of this effect, based on a model of activated capillary condensation, is proposed.