A Study on Electric Arc Furnace Steelmaking Slag Used as Green Building Materials
| Autor: | zhen-hui Li, 李震輝 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 The aim of this study was to evaluate the feasibility of EAF reduction slag powder, calcium hydroxide, and ground granulated blast furnace slag used as binder materials and used to produce mortar and block with EAF oxidation slag. The effect of addition level and fineness of EAF reduction slag on the characteristics of binder materials would be investigated. Furthermore, the effect of addition level of EAF reduction slag and aggregate type on the characteristics of mortar would be also investigated. Then the block production parameters were designed according to Taguchi experimental design method, and the block specimen was further fabricated. Finally, the S/N ratio and analysis of variance on compressive strength of block were used to evaluate the performance of block production. The results show that EAF reduction slag is really promising to be used as a binder materials, and the roughness and the porosity of EAF oxidation slag surface are helpful for the binding with binder materials when EAF oxidation slags are used as the aggregates. The activity of the EAF reduction slags can be improved while the fineness of EAF reduction slags increase, and the compressive strength of the binder materials can also be improved. When the fineness of EAF reduction slag was 6770 cm2/g, the 28th day compressive strength binder materials is able to achieve 27-28 MPa. The expansion rate of binder materialss with different addition level are respectively less than 0.02% after autoclave test, it shows that the binder materials with EAF reduction slags was stable. When addition level of the EAF reduction slag increased from 0% to 60%, the compressive strength of mortar remained at the same level and the 28th day compressive strength of mortar could reach 28 MPa. The result of ASTM C1260 test shows the mortar produced by that the EAF oxidation slags as fine aggregates has the potentially expansibility of volume. The result of autoclave test shows that the mortar-bar produced by EAF oxidation slags as fine aggregates has broken and the white powders were found and brown powders at the broken place. The white powders and brown powders are sampled and analyzed by XRD. The main components of white and brown powders are Mg(OH)2 and Ca(OH)2, respectively. The blocks produced with EAF oxidation slag used as aggregates show higher compressive strength than blocks produced with natural aggregates. It could also result from the rough surface and the higher porosity and specific gravity of EAF oxidation slag used as aggregates, which can provide adhere better with the binder materials. According to the results of S/N analysis and analysis of variance, the five factors influencing the performance of compressive strength of blocks are listed below in sequence：aggregate type (B) > aggregate / binder ratio (D) > water / binder ratio (C) > coarse / fine aggregate ratio (E) > EAF reduction slag add ratio (A). The result of ASTM C1260 test shows that the prism produced by EAF oxidation slags as fine aggregates has broken and the white matters were found at the broken place. The white matters are sampled and analyzed by XRD. The main components of white matters are MgO and Mg(OH)2 . |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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