| 摘要: | 自松菸文創爐碴屋事件之後政府開始重視廢棄爐碴之管制，並且針對爐碴之再利用新增及修正相關管理條文，但目前國內較缺乏系統化之爐碴再利用流程與檢測標準，且由於現行法規較無詳細之爐碴檢測方式，業界所執行之標準亦多為自行制定，因此，本研究通過建立電弧爐碴用於水泥基質材料時之檢測方式並提出參考之標準，以補充此部分之缺失。
本研究主要針對含電弧爐碴之細粒料，藉由對其進行化學分析（pH值試驗分析、酚酞變色試驗、光學顯微鏡分析及XRF元素含量）及物理分析（膨脹量試驗、外觀形貌及抗壓強度）方式，探討摻入電弧爐碴對細粒料及水泥基質材料之影響，並以此為基礎初步建立系統化檢測標準，期以此提出較為簡易、快速、準確且可以因地制宜之檢測方法，以保證結構物之安全性。
化學分析方面，首先提出pH值標準作業化流程，通過以不同粒料類型、粒徑、固含量、水質情況與濾紙規格時之測試結果，提出簡易且準確之測試方式，且藉由前導試驗決定之控制變因進行爐碴摻配之pH值試驗，探討不同摻配量對pH值之影響，並分析各種爐碴在不同粒徑大小與摻配比例下之變化；酚酞變色實驗中，藉由酚酞因鹼性變色原理，探討爐碴尺寸及摻配量與酚酞顏色變化之關係；光學顯微鏡分析則以酚酞直接噴灑粒料表層並藉由光學顯微鏡進行觀察，並透過顆粒計算方式及面積計算方式探討選擇最適合之計算方式及其最大誤差值；藉由XRF分析可得爐碴之化學成分，並綜合化學分析之結果與物理分析做綜合探討。物理分析方面則主要探討不同摻配比例之爐碴對於水泥基質材料之影響。膨脹量試驗選用環境為高溫高鹼、高溫高壓及常溫常壓（室溫環境)，藉由不同環境下探討不同摻配下爐碴對於水泥基質材料膨脹量之影響，抗壓強度選用環境為高溫高壓環境並進行2次蒸壓，探討抗壓強度、摻配比例及蒸壓次數之關係。
化學分析之結果顯示，測試結果之pH值隨粒徑縮小而提升，且可通過pH值是否≥ 9判別粒料摻有爐碴之可能。經測試後之酚酞所呈現之顏色主要為透明/白色、淡紅色以及深紅色，且顏色飽和程度隨粒徑縮小及摻量提升而增加。光學顯微鏡分析以顆粒計算爐碴方式中大區域爐碴最大佔比方式計算較為適用，最大誤差不超過20%。由XRF可知天然粒料主要成分為SiO2，其次為Al2O3，而氧化碴與還原碴皆以CaO為主。物理分析結果顯示，使用室溫環境之檢測方式，須將試驗齡期提升至120天以上，方能觀測其與對照組之差異。使用高溫高鹼環境之檢測方式，試驗齡期5天時即可有效觀察砂漿棒因爐碴膨脹性造成之影響，多數試體斷裂情況須達到齡期21天。使用高溫高壓環境之檢測方式發現，其蒸壓後之膨脹量隨爐碴摻配量提升而增加，蒸壓後之抗壓強度則出現不同程度損失。砂漿棒之膨脹量隨蒸壓時間之增加而提升，在3小時時提升約達1.0至1.4倍，增加至6小時時再提升約達1.0至1.6倍，藉此可觀察爐碴之膨脹現象。砂漿塊蒸壓劣化後，藉由試體外觀形貌進行初步分級，由優至劣分別為A-E五級。其抗壓強度試驗結果顯示，在3小時時約損失約達1.2至3.4倍，增加至6小時時氧化碴抗壓強度再損失約達1.1至1.5倍，還原碴則在6小時強度較不穩定，可能為高溫環境下促進水泥與還原碴之水化反應。
藉由試驗結果訂定爐碴檢測流程：(1)將樣本首先通過酚酞變色試驗進行初步判別，(2)使用pH值試驗進行驗證其摻有爐碴之比例範圍，(3)以光學顯微鏡之顆粒計算方式推測其爐碴準確含量，(4)若所含之比例過高則可製作砂漿試體進行高溫高壓環境檢測用以驗證其安全性。
;This research aims to evaluate the characteristic of fine particles containing electric arc furnace slags, by chemical analysis (pH value analysis, Phenolphthalein Test, optical microscope analysis, and XRF analysis) and physical analysis (expansion test, appearance and morphology, and Compressive strength test), to explore the influence of adding electric arc furnace slags on fine aggregates and cement matrix materials, and to initially establish a systematic testing standard based on those results. This research desires to put forward a simpler, faster, more accurate testing method that can be adapted to local conditions, to ensure the safety of the structure.
The results of the chemical analysis show that the pH value of the test results increases with the reduction of particle size. The possibility that the pellets are mixed with slag can be judged by whether the pH value is ≥ 9. The color of phenolphthalein after testing is mainly transparent/white, light red, and dark red, and the color saturation degree increases with the decrease of particle size and the increase of dosage. Optical microscope analysis is more suitable for calculating the maximum proportion of large-area slags in the particle calculation, and the maximum error does not exceed 20%. It can be seen from XRF that the main component of natural pellets is SiO2, followed by Al2O3. Both the oxidized slags and the reduced slags are mainly composed of CaO. The results of the physical analysis show that, for the control group, the test age must be increased to more than 120 days in order to observe differences when using the detection method at room temperature. Using the detection method in high temperature and high alkali environment, the influence of the mortar rod due to the expansion of the slag can be effectively observed when the test age is 5 days. Testing those specimens in high temperature and high-pressure environment, it was found that the expansion amount after autoclaving increased with the increase of the slags mixed, and the compressive strength after autoclaving showed different degrees of strength reduction. The expansion of the mortar bar increases with the increase of the autoclaving time. The expansion of the slags can be observed about 1.0 to 1.4 times at 3 hours, and then increases by about 1.0 to 1.6 times when it increases to 6 hours. After the autoclaved deterioration of the mortar block, preliminary classification was carried out based on the appearance of the specimen, and the grades were A-E from good to bad. The compressive strength test results show that the reduction is about 1.2 to 3.4 times at 3 hours, the compressive strength of oxidized slags is reduced by about 1.1 to 1.5 times when it increases to 6 hours, and the reduced slags are less stable at 6 hours. These results can be explained due to the hydration reaction of cement and reduced slags under high temperature.
According to this research results, the slags detection process is determined as follows: (1) The sample is firstly judged by the phenolphthalein discoloration test, (2) The pH value test is used to verify the proportion of the slags mixed, (3) The optical microscope is used to determine the proportion of the slags. The particle calculation method infers the accurate content of the slag. (4) If the proportion contained is too high, a mortar sample can be made for high temperature and high-pressure environmental testing to verify its safety. |
