| The study and application of steel slag admixture of concrete in our country had several years of history, moreover the national standards of steel slag cement has promulgated very early, but compared with the slag and the fly ash, the utilization ratio of the steel slag was also very low in concrete. The present study mostly on the hot poured steel slag and the water quenching steel slag, the Lack of research on pyrolytic converter steel slag(PCSS). To improve the utilization ratio of PCSS in concrete, it is necessary to study and analyze various performance of PCSS. Therefore, this article mainly on experimental study, the cementious properties of PCSS and used as admixture of high performance concrete were studied,the main contents are as follows:(1) basic properties of PCSS. The results showed that PCSS has chemical composition similar to that of Portland cement, the dosage of CaO,SiO2,and Al2O3 are lower than Portland cementl; PCSS has three major minerals:silicate minerals, ferrite solid solution and RO phase, but the dosage of silicate minerals is 41.34%; silicate minerals,olivine, MgO solid solution and FeO solid solution are easy to grinding, while ferrous minerals and olivine are difficult to grinding; the radioactive of PCSS is meet the standard and can be used as concrete admixtures.(2) cementious properties of PCSS. The results showed that PCSS has a hardening activity without the excited of gypsum; the activity index of mortar is 84.8% with the 25% dosage of PCSS(569m2/kg); the binary complex effects of PCSS and fly ash are better than PCSS and slag; gypsum is the optimal activator compared with calcium hydroxide and solid sodium silicate; With the increase of dosage of PCSS,the fluidity of mortar is larger,while the fluidity of mortar is smaller with the dosage of PCSS beyond 40%;PCSS are more adapt to P·C32.5R than P·O42.5R.(3)composition and microstructure of hydration products of PCSS. The composition and morphology characteristics of hydration products of paste with PCSS in different ages were studied by XRD and SEM. The results shows that, the types of hydration products at different ages in different hydration are similar. at post-hydration, hydrated samples with 25% PCSS and pure cement paste had similar ettringite and C-S-H diffraction peak intensity. PCSS mixed with slag has a stonger Ettringite and C-S-H diffraction peak intensity than PCSS mixed with fly ash.the dosage of hydration products of the paste with 25% PCSS sharply increase in post-hydration, except for mass flocculent C-S-H gel and cascade distribution six-sheet Ca(OH)2 crystal, Also found a small amount of needle stick ettringite. compared with pure cement paste, the paste with 25% PCSS had fewer hydration products,and the shape of ettringite is short stick mostly.(4)mechanical properties and workability of concrete with PCSS.The results showed that PCSS can improve the workability of concrete;the activity index of concrete beyonded 80% with 25% PCSS;gypsum can improve compressive strength of concrete with PCSS; the binary complex effects of PCSS and fly ash or slag are better than uni doped PCSS, and the binary complex effects of PCSS and slag are better than control group.(5)durability of concrete with PCSS. Using rapid chloride penetrability tester tested the chloride-permeation resistance of PCSS concrete. The results showed that, steel slag can improve the performance of resist chloride-permeation of concrete when the dosage of PCSS is lower than 20%, but when the dosage of PCSS more than 20%, the performance of resist chloride-permeation of concrete were getting weaker.This article provided a basis research on study and large-scale application of high performance concrete with PCSS,and provided the application technical standard a important reference of high performance concrete with PCSS.
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