Research On Grouting Material With CFBC Fly Ash

CFBC fly ash is generated by adding calcium to desulfurize in circulating fluidized bed combustion boiler.The performance of the CFBC fly ash is different from the ash generated by common coal furnace.Grouting is one of the most widely used technology of geological disaster prevention and ground improvement.It is a important way of desulfurized fly ash Comprehensive Utilization by applying it to grouting engineering which can bring magnitude social environmental and economical benefits.The performance of grouting is researched in this paper based on the experiment of desulfurized fly ash grouting materials.The main work is as follows:(1)The physical and chemical properties of desulfurized fly ash of Jin Ling thermoelectrical plant are researched.It is found that the chemical composition of the desulfurized fly ash is basically the same as that of the common fly ash except the higher content of CaO and loss on ignition.The main mineral phases areα-SiO₂,gypsum,calcite,lime,and Fe2O3,but mullite andβ-SiO2 are not discovered which formed at high temperature.The partical of this desulfurized fly ash appears as abnomal crumb figure.The desulfurized fly has small loosen volumeweight,lower specific surface area compared with national ashes and good particle grade.(2)The microelement and radioactivity safety evaluation is researched.It is found that there is no great difference between the desulfurized fly ash and common fly ash.The contents of the venomous nocuous and radioactive elements mainly satisfy the demand of the national criterions.(3)The desulfurized fly ash grouting material performance is researched based on a great deal of experiments.The study shows that the physical and chemical properties of desulfurized fly ash has a great influence to the performance of the grouting material.The performance indexes of grouting material have a good linear correlation with the water solid ratio and the content of the desulfurized fly ash.(4)The improvement effect and influence to the desulfurized fly ash gouting material performance is studied by adding four additives such as Na2CO3,Na2SO4,bentonite and JM-B.It shows that the additives greatly improve the grouting material performance and have a better effect than other additives.(5)The rheology experiment of the desulfurized fly ash grouting material is taken.The study shows that there are two flow pattern such as HB and Bingham.The critical water solid ratio is higher than common grouts. The desulfurized fly ash grout belongs to shear dilute grout.(6)The comparative experiment of F kind fly ash grouting material is taken.It shows that the performance of the desulfurized fly ash grouting material is better than that of the F kind fly ash grouting material.