The Preparation And Properties Research On Alikali Activated Steel Slag-slag Grouting Material

Grouting materials currently used include chemical grouting material,superfine cement grouting material,cement water glass grouting materials,which have the disadvantage of high cost,poor durability,poor environmental friendly and so on,can not meet the growing development requirements of green and high performance.China has a large number of steel slag,slag and other industrial wastes,especially steel slag with the low rate of comprehensive utilization,not only occupy a lot of land,but also caused a huge waste of resources.According to the principle of alkali activated cementitious materials,using steel slag,slag as the main raw material,using water glass as activator and adding retarder?water reducing agent and expansion agent developed a new the green grouting material.According to the characteristics of grouting materials,the influence of the raw materials on properties of grouting materials,such as fluidity,setting time and consolidation strength,were studied systematically,and the optimum mix proportion was determined.At the same time the effects of the amount of steel slag?the type and content of the expansion agent on the shrinkage and impermeability of the grouting material were studied,the optimum type and content of expansion agent were determined,and on the basis of this,its resistance to carbonation was studied.Combined with XRD,SEM and mercury porosimetry method,the relationship among the hydration product composition,microstructure,characteristics of pore structure and properties was studied,then the hydration and hardening mechanism was discussed briefly.The results of this study showed that the amount of steel slag is in 40%~50%,the water glass modulus is in 1.2~1.4 and the dosage is about 10%~12%,the dosage of retarder and water reducer are 1.5% and 1% respectively,and the dosage of HCSA or FQY expansive agent is 8%,grouting material slurry water segregation rate is less than 3%,the initial fluidity can reach more than 280 mm,the setting time is larger than 90 min,and 1d,3d,28 d consolidation strength can reach more than 10 MPa,30MPa,50 MPa respectively;improving the amount of steel slag and adding HCSA or FQY expansive agent can significantly improve the shrinkage performance of grouting materials,reduce stone porosity,improve the ability to resist chloride ion penetration,but adding expansive agent could shorten the setting time and diminish the fluidity of grouting materials,and it is suggested that the amount of FQY or HCSA expansion agent is in 4%~8%,the fluidity of grouting material can reach 260 mm,the setting time is about 70min;main hydration products of grouting material are C-S-H?C-S-A-H and zeolite products,when adding expansive agent,zeolite products disappear,due to carbonation Aft and CH are not detected either;40%~50% of steel slag is a more reasonable proportion of steel slag-slag which appeare synergistic effect in hydration process,and is favorable to the hydration degree of grouting material.In this paper,the new green high performance grouting material with a composition of steel slag-slag,water glass,and several admixtures can be produced with good liquidity,controllable setting time,high strength and non-shrinkage.There are good prospects in exploiting industrial by-products and its simple preparation technology.