Title:
STUDY ON THE MECHANISM OF DESORPTION BEHAVIOR OF SATURATED SAP IN CONCRETE
Author(s):
Fazhou Wang, Jin Yang, Hua Cheng, Jing Wu, and Xiongyi Liang
Publication:
Materials Journal
Volume:
112
Issue:
3
Appears on pages(s):
463-470
Keywords:
desorption; different stages; humidity gradient; osmotic pressure; pH value; superabsorbent polymers.
DOI:
10.14359/51686996
Date:
5/1/2015
Abstract:
The effect of several potential factors on the desorption behavior of saturated superabsorbent polymers (SAPs) in concrete was studied by simulating the internal saline concentration, alkalinity, and relative humidity. Results indicate that the desorption of SAP is mainly decided by osmotic pressure and humidity gradient. The desorption
process of SAP is divided into three stages: the leading factor is the osmotic pressure during the first stage; humidity gradient during the third stage; and a relatively low-level combination of these two factors during the second stage. At the same time, the desorption is not decided by pH value, and the factor with the most effect is the osmotic pressure. The water release rate Rt of saturated SAP influenced by humidity shows the following trends: Rt indicates a clear linear trend as a function of time, and an approximate logarithm correlation exists between Rt and the relative humidity (Rt = A • ln(RH) + B).
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