Water Absorption-release Behavior of SAP and Influence Mechanism on Concrete Properties:A Review
Superabsorbent polymer(SAP)has been developed as an optimum internal curing material for concrete owing to its superior absorption,storage,and water release behavior.To better understand the relationship between SAP water absorption-release behavior and concrete performance and increase the curing efficiency of SAP,three theories of SAP water absorption-release were summarized.The water absorption-release behavior in different solutions,water exchange mechanism between SAP and cement paste,and relationship between SAP and concrete internal humidity were systematically analyzed.The test methods of SAP water migration behavior were summarized,and the characteristics and applicability of each method were analyzed.The effects of the SAP particle size,dosage,and entrained water amount on concrete properties were discussed from the perspectives of cement hydration,pore structure,and micro-morphology.The results show that the ionic network,solution thermodynamic,and gel phase transition theories can explain the water absorption-release behavior of SAP in different solutions,and the amount of adsorbed and capillary water in SAP affects the water release time of SAP.The water absorption-release properties of the SAP determine the moisture distribution in concrete.The microstructure and macroscopic properties of SAP internal curing concrete are comprehensively influenced by SAP dosage,particle size,and entrained water amount.Appropriate parameters enable hydration products to fill the pores created by SAP,thus refining the concrete pore structure and improving compactness,mechanical properties,and durability.Additionally,the self-healing capacity,resistance to fire spalling,and algae cultivation of concrete are increased by SAP.To improve the design of the internal curing concrete of SAP,the morphological evolution of SAP and its water absorption-release behavior in concrete,as well as the relationship between SAP and water distribution,should be clarified.
NETL
NSTL
万方数据
维普
