Effect of Composite Expansive Agent on Early-Age Expansion Properties of Cementitious Grouting Material for Wind Power Project
HAN Yudong
XIE Yue
YUE Qingrui
YANG Feng
DING Zhenyue
Abstract：Based on an improved vertical expansion rate(εv)testing method,the development of εv of high-strength cementitious grouting material for wind power project within 0-24 hours and 1-7 days was obtained.The effects of the proportions of mineral admixtures as well as expansive agents on εv,fluidity and mechanical strength of grouting material were experimentally investigated.Results show that a typical developing characteristic with"four stages"is observed in the curves of εv-time of grouting material during 0-24 hours.With the increase of silica fume percentage in the range of 0%-20%,the fluidity of grouting material decreases gradually,and the peak value of εv firstly increases and then decreases from casting to 24 hours.Plastic expansive agent(PEA)dominants the development of εv within 24 hours.Furthermore,calcium sulphoaluminate-calcium oxide expansive agent(HP-CSA)is added,the peak value of εv decreases,the 24 h-value decreases,and the 3 h-value increases,which is beneficial to the control of the difference between the 24 h-value and 3 h-value.During the age of 1-7 days,the expansive efficiency of HP-CSA can well be promoted by PEA with addition of 0.03%.And the vertical autogenous shrinkage can generally be"compensated"by HP-CSA with the addition percentage not less than 6%,resulting in a grouting material with a net expansion during the period either 0-24 hours or 1-7 days.Relay effect in time and synergistic effect in outcome on expansion regulation for the grouting material are observed when PEA and HP-CSA composite are used,and if an appropriate dosage is found,a fine regulation on εv is well achieved in stages within 7 days.In addition,with the increase of the composite expansive agent,the initial and 30 mins values of fluidity of the grouting material shows little change,and the compressive strength at 28 days first increases and then decreases.Within the scope of this study,PEA at 0.06%and HP-CSA at 6%is comprehensively the optimal dosage composite.
Keywords：high-strength cementitious grouting material for wind power projectvertical expansion rateplastic expansive agentcalcium sulphoaluminate-calcium oxide expansive agent(HP-CSA)composite and synergistic effect
Publication Date：2024-07-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 611-619 )