Title:
The Effect of Particle Size and Dosage of Sodium Polyacrylate (PAAS) on Mechanical Properties and Hydration Properties in Fly Ash Cementitious Materials (Prepublished)
Author(s):
Jingjing Lyu and Shuo Feng
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
hydration products; mechanical properties; sodium polyacrylate（PAAS); unhydrated cement particles
DOI:
10.14359/51751789
Date:
6/9/2026
Abstract:
This study investigated the effects of sodium polyacrylate (PAAS) particle size and dosage on the workability, strength, and hydration of cementitious materials. The backscattered electron banding (BSE) was used to quantitatively analyze the degree of hydration of cement around PAAS voids under varying humidity levels. The results indicated that mortar fluidity, compressive strength, and flexural strength gradually decreased with increasing PAAS particle size and dosage. The incorporation of fine PAAS particles (45–50 μm) enhanced mechanical strength. While PAAS does not alter hydration product types, it promotes calcium carbonate formation, with calcium hydroxide, calcite, and C3S remaining dominant. Furthermore, it was found that higher humidity conditions and larger particle size PAAS particles can reduce the amount of unhydrated cement in the area around PAAS voids.