|摘要: || 本研究探討淨水污泥餅再利用於控制性低強度材料(CLSM)，淨水污泥餅取自台北自來水事業處直潭淨水場。研究目的為探討：(1)淨水汙泥餅特性、(2)水膠比、取代比及早強劑添加量等參數對CLSM之影響、及(3)CLSM之特性。淨水污泥餅與CLSM特性包含物化、溶出及顯微特性，以ICP、FTIR及XRD等檢測物化與顯微特性，此外，以工作性(管流度、坍度、坍流度)與抗壓強度評估淨水污泥餅再利用於CLSM之影響。|
淨水污泥餅與CLSM之物化及顯微分析結果顯示，淨水污泥餅主要以矽及鋁等元素之氧化物組成，分別佔53.2%與23.2%，此結果與FTIR、XRD分析之結果相符，且淨水污泥餅之TCLP溶出試驗值低於法規之限值，屬於一般事業廢棄物。此外，添加淨水污泥餅後CLSM之物化、溶出及顯微特性亦與淨水污泥餅之特性相似。於取代比10%之情況下，CLSM工作性隨著水膠比增加而改善，水膠比1.00即可達到CLSM施工規範之要求，但抗壓強度卻隨之降低，且1天抗壓強度顯著減少至1.12 kgf/cm2，無法達到規範要求之7 kgf/cm2。此外，水膠比對CLSM工作性之影響大於取代比，當取代比於0%~10%時，水膠比由1.30降至1.00，CLMS工作性增加3.2%至53.8%，CLSM工作隨水膠比降低而增加。於本研究之最適條件下:水膠比1.15、取代比10%，CLSM工作性可達規範要求，但1天抗壓強度無法符合。因此本研究以水膠比0.85、取代比10%之CLSM，添加早強劑至100 kg/m3，其1天抗壓強度可達19.57 kgf/cm2，且初凝時間縮短至3.82小時，可符合規範要求。但早強劑添加量應低於水泥添加量之5%，過量可能對管材造成腐蝕等破壞。
This study investigates the feasibility of reusing water treatment sludge cake in controlled low strength materials (CLSM). The sludge cake is from Chihtan water purification plant, Taipei water department. The objectives to this study are to investigate: (1) the characteristics of sludge cake, (2) the effects of water-to-binder ratio, (cement) replacement ratio and early strength agent addition to CLSM, and (3) the characteristics of CLSM been made. The characteristics of either sludge cake or CLSM are determined by physiochemical characters, leaching characters and microscopic phenomena. The inductively coupled plasma (ICP), Fourier transform infrared spectroscopy (FTIR) and X-ray Diffraction (XRD) are applied for measuring physiochemical and microscopic features. In addition, the feasibility of reusing sludge cake as CLSM is also determined by measuring their workability (flow consistency, slump and slump flow) and compressive strength.
The results showed that the water treatment sludge cake mainly composed of SiO2 (53.2%) and Al2O3 (23.2%), which is consistent to the results from FTIR and XRD analysis. The results from toxicity characteristic leaching procedure (TCLP) indicate that the water treatment sludge cake is safe to the environment by regulations.
At 10% replacement ratio, the workability of CLSM increases with water-to-binder ratio, and at the water-to-binder ratio of 1.00, the CLSM could meet the requirement of construction specification. However, the compressive strength decreases with increasing water-to-binder ratio and it decreases to 1.12 kgf/cm2 which fails to meet the construction specification (7.0 kgf/cm2). The effect of water-to-binder ratio on CLSM workability is more significant than that of replacement ratio. For replacement ratio ranging from 0% to 10%, the CLSM workability increases from 3.2% to 53.8%, when water-to-binder ratio decreases from 1.30 to 1.00. this results show that CLSM workability increases with decreaing water-to-binder ratio. Even though the CLSM workability can meet the specifications at the optimum condition in this study which water-to-binder ration is 1.15 and replacement ratio is 10%, the 1-day compressive strength cannot. In order to increase the compressive strength, 100 kg/m3 of early strength agent is added to the CLSM at 0.85 water-to-binder ratio and 10% replacement ratio. The 1-day compressive strength increases to 19.6 kgf/cm2 and the initial setting time decreases to 3.82 hours which can meet the specification. However, the addition of early strength agent should be lower than 5% for reducing the risk of corrosion to the pipeline.