Effect Of Sulfate And Granulated Blast Fumace Slag On Properties Of Sulphoaluminate Cement-based Grouting Material

The calcium sulfoaluminate(CSA)cement based double liquids grouting material(CSA-DLGM)has the advantages of quick setting and early strength,but its strength is easy to shrink or not to increase.In order to further explore and improve its performance,the influence of sulfate and The granulated blast fumace slag(GBFS)on CSA-DLGM material is adopted.The setting time and compressive strength of CSA-DLGM material are tested when the content of sulfate and mineral powder is different The influence mechanism of hydration heat was analyzed by using XRD,TG-DTA,SEM and other testing techniques.The main conclusions are as follows:(1)The effects of different sulfates on the properties of CSA-DLGM were studied.The results show that different sulfates have different effects on the setting time and compressive strength of CSA-DLGM.Magnesium sulfate has little effect on the setting time of the material.Aluminum sulfate can shorten the final setting time by 70.2% at most,but has no significant effect on the compressive strength.Aluminum potassium sulfate can shorten the setting time by 41.5% at most,but it has no positive effect on compressive strength more than 1 day.Sodium sulfate can promote the early hydration of CSA-DLGM material,and can change the early morphology of the hydration product ettringite,making it smaller,which will help to improve the compressive strength of 2h.When the compressive strength of 2hours is the highest,the content of sodium sulfate is 3%,and the setting time is shortened with the increase of the content of sodium sulfate.Potassium sulfate can promote the early hydration of CSA-DLGM material,and can change the early morphology of the hydrated product ettringite to make it more slender,so too much potassium sulfate is not conducive to the growth of 2h compressive strength.When the compressive strength of 2H is the highest,the content of sodium sulfate is 1%,and the setting time is shortened with the increase of the content of potassium sulfate.(2).The effects of sodium sulfate,potassium sulfate,aluminum potassium sulfate and GBFS on the performance of CSA-DLGM materials were studied.The substitution amount of GBFS has the greatest influence,followed by aluminum potassium sulfate eighteen hydrate,and the influence degree of potassium sulfate and sodium sulfate is general.The larger the substitution of GBFS,the longer the setting hardening time and the lower the compressive strength at early age.(3)The effect of sodium sulfate and GBFS on the properties of CSA-DLGM material was studied.The results show that the substitution of GBFS is beneficial to the development of compressive strength in the later period,because the activity of mineral powder is excited after 28 days,which is conducive to the increase of compressive strength.When 2% sodium sulfate was added and the amount of GBFS substitution was20%,the compressive strength of 28d and 90d were 123.5% and 110.8% of the compressive strength of the sodium sulfate-only group,respectively.In this paper,the influence of sulfate and GBFS on the sulfoaluminate cement-based grouting material is studied,which provides some reference value for the further modification of the grouting material.