Study on harmory between setting time and free shrinkage displacement of mortar modified by polymer
LIU Sichun
Abstract：This paper studied the determination method of setting time of mortar based on the characteristic of free shrinkage deformation,the evolution rule of the plastic free shrinkage deformation with time of mortars modified by 5%,10%,15%,20% EVA powder was measured. Compared setting time with the test method of penetration resistance,the setting time and its corresponding free shrinkage deformation was determined. The experimental results show that the deformations behavior of mortars with different EVA contents all the first appear plastic swelling and then exhibit shrinkage. EVA powder reduces the effective free shrinkage deformation,prolong the mortar setting time,delay the occurrence of harmful deformation,and the more content,the more obvious effects. The mortar setting time by free shrinkage deformation test(Ta) is earlier than by penetration resistance test(Ts). And the former could be more truly reflect the transformation process of mortar from the plastic flow state to the semi/solid state;EVA powder can reduce the starting temperature,the peak temperature and the area of Ca(OH)2 endothermic peak and delay the ce-ment hydration,and the more dosage,the more obvious effect.
Keywords：mortarEVA polymersetting timeplastic free shrinkage
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 44-47,116 )