Aggregate water absorption: meaning and interpretation

English technical overview

Water absorption describes the water taken into accessible pores under a defined laboratory procedure, usually expressed relative to oven-dry mass. It is not the same as surface moisture, total moisture, porosity or drainage through a stockpile. Saturated-surface-dry condition provides a useful boundary between absorbed water and free surface water. Coarse and fine aggregates require their corresponding methods; ASTM C127 and C128, and related road-agency procedures, should not be blended without checking scope and edition. The Persian guide explains moisture states, an explicitly hypothetical mass calculation, concrete-water corrections, railway-ballast interpretation, sample identity and common laboratory errors. A low absorption value alone does not certify durability or the safety of a railway. Published results must remain connected to an identified sample, method and applicable project criteria. Existing mine photographs illustrate the material and are not laboratory evidence.