Micro-observations of different types of nano-Al₂O₃on the hydration of cement paste with sludge ash replacement.
In recent years, sewer systems and wastewater treatment plants have become important in developing countries. Consequently, the amount of sewage sludge produced by these countries has been gradually increasing, and determining how to properly recycle this sludge is becoming an important topic for researchers. In this study, to expand the recyclability of sewage sludge ash (SSA) in engineering applications, two types of nano-aluminium oxides (Al₂O₃), MC2A and MC2R, were added to SSA/cement paste and mortar specimens. The MC2R type (γ phase) had a smaller particle size and larger specific surface area than the MC2A type (α phase). The results indicate that the addition of nano-Al₂O₃to SSA/cement paste can effectively improve the hydration products of the paste. Moreover, the amount of hydration products increased as the amount of nano-Al₂O₃added to the SSA/cement paste increased. The test results indicate that MC2A nano-Al₂O₃can more uniformly distribute in the paste body and improve the hydration of cement than MC2R nano-Al₂O₃. Thus, more calcium-silicate-hydrate (C-S-H) gel and calcium aluminate hydrate (C-A-H) salts were produced, and the strength of the specimens was improved. This study suggests that MC2A nano-Al₂O₃is preferable to MC2R nano- Al₂O₃for SSA/cement specimen applications.
a Department of Civil and Ecological Engineering , I-Shou University , No. 1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001 , Taiwan, ROC.
Huan-Lin
HL
Luo
a Department of Civil and Ecological Engineering , I-Shou University , No. 1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001 , Taiwan, ROC.
Deng-Fong
DF
Lin
b Department of Liberal Education , Shu-Te University , Kaohsiung City 82445 , Taiwan, ROC.
Show-Ing
SI
Shieh
a Department of Civil and Ecological Engineering , I-Shou University , No. 1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001 , Taiwan, ROC.
Yan-Fei
YF
You
D000537:Aluminum Oxide / Q000737:chemistry*; D001151:Arsenic / Q000032:analysis; D019245:Compressive Strength; D003252:Construction Materials; D007220:Industrial Waste; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D012722:Sewage; D014874:Water Pollutants, Chemical / Q000032:analysis; D014961:X-Ray Diffraction
D007220:Industrial Waste; D008670:Metals; D012722:Sewage; D014874:Water Pollutants, Chemical; D000537:Aluminum Oxide; D001151:Arsenic
cement; micro-structure; nanomaterial; paste; sludge ash