Effect of curing temperature on properties of mortar with different accelerators
WANG Jibo
ZHANG Zhigang
DANG Haishuai
LI Hengjin
LIU Yahui
WAN Zhenmin
XIE Xiangbing
Abstract：This study explores the effects of three curing temperatures(5,20 and 35℃)on the setting time of accelerator-added cement paste,the mechanical properties and shrinkage of accelerator-added mortar,using XRD,FT-IR,and SEM to clarify the temperature mechanism.Results show lower temperatures delay cement paste's setting,reduce compressive strength,especially early strength.At 5℃,AS's properties worsen significantly,failing to meet requirements for setting time in standard GB/T 35159-2017"Flash Setting Admixture for Shotcrete"and dropping 1 d strength by 63.6%compared to that at 20℃.Higher temperatures speed up hydration and increase hydrate quantities,particularly at 1 d age.However,also aggravate shrinkage,with AR-added mor-tar at 35℃having 25%higher shrinkage than at 20℃after 90 days.Microscopic tests reveal low-temperature curing reduces early C-S-H peak intensity and AFt quantity in AS-added paste,leaving many unhydrated minerals.High-temperature curing ac-celerates early hydration,with AR-added mortar showing less AFt and more AFm,and having weak shrinkage restriction.
Keywords：liquid acceleratorshotcretesetting hardeningearly strengthvolume stability
Publication Date：2025-09-25
Online Publishing Date：2025-10-15(First online date of this platform, not the publication date of the document)
Pages：8( 70-76,144 )