The Sduty Of Properties Of Cement And Concrete Prepared With Circulating Fluidized Bed Combustion Ashes

Circling fluidized bed combustion technology has been the mainstream of coalburning boiler because of its efficient solid sulfur efficiency. The fly ash and bottomslag （FBC for short） is the waste of coal burning as a result of the advanced technology,including the circling fluidized bed combustion fly ash （FBCF） from the funnel and thecircling fluidized bed combustion bottom slag （FBCB） from the furnace bottom. FBCprocesses the characteristic of high water demand and linear expansion （mainlyreferred to its high SO₃and f-CaO content）、self-harding and high pozzolandic activityand has not been resource using in a large scale. This paper mainly studies theperformance of cement and concrete （mainly strength and volume stability） with FBCadded.Because it is a product of efficient desulfurization technology, generally the SO₃content of FBC is relatively high, and in the form of anhydrite. Studies have shown thatanhydrite can be used in cement and improve the performance of cement andconcrete. With the development of efficient desulfurization technologies, standard, onSO₃regulations should not be confined to high-sulfur waste but on their system,limited. Considering that cement mixed with the FBC as admixture directly may exceedthe limits of SO₃, that the Universal Portland Cement Standard GB175-2007provisionor lower the utilization of FBC using cement clinker when meet standard, so in thisarticle clinker is used instead of cement, in order to use arger content of as much aspossible under the premise that meet the standard requirements and performance ofcement and concrete.Based on FBC content changes in the cement clinker, this paper studied bisicperformance of cement density, fineness, the amount of water of normal consistency andsetting time, stability, linear expansion and superplasticizer compatibility, and comparedwith controlled cement. The results showed that cement mixed with FBCF or FBCBappeared relatively good performance in about20%content. Meanwhile, experimentaluse of alternate conservation studied on the volume stability of cement, the resultsshowed that after alternative curing the long-term strength did not reduce, but more thanthat after standard curing. Taking into account the different FBC discharge methods andits origin, as well as the grinding in order to improve the activity and contribute to theadvance digestion of the anhydrite. On the basis of20%FBC content, this paper studied the strength and linear expansion and shrinking changes of cement with different sulfurcontent and different fineness desulfurization. The results showed that cementperformance changed with finess change but little with sulfur content.Based on the above rusults, this paper studied the performance of concrete, theresullt showed that the performance of concrete changed little with sulfur content ofFBC. The result of finess changes showed that the strength of concrete improved withfiness increased. After alternative curing, the strength of concrete with FBC was higherthan that of air cuing but lower than that of standard curing. There was not obviouscompatibility problems between concrete with FBC and superplasticizer.