title: Improvements of nano-SiO2 on sludge/fly ash mortar.
abstract: Sewage sludge ash has been widely applied to cementitious materials. In this study, in order to determine effects of nano-SiO(2) additives on properties of sludge/fly ash mortar, different amounts of nano-SiO(2) were added to sludge/fly ash mortar specimens to investigate their physical properties and micro-structures. A water-binding ratio of 0.7 was assigned to the mix. Substitution amounts of 0%, 10%, 20%, and 30% of sludge/fly ash (1:1 ratio) were proposed. Moreover, 0%, 1%, 2%, and 3% of nano-SiO(2) was added to the mix. Tests, including SEM and compressive strength, were carried out on mortar specimens cured at 3, 7, and 28 days. Results showed that sludge/fly ash can make the crystals of cement hydration product finer. Moreover, crystals increased after nano-SiO(2) was added. Hence, nano-SiO(2) can improve the effects of sludge/fly ash on the hydration of mortar. Further, due to the low pozzolanic reaction active index of sludge ash, early compressive strengths of sludge/fly ash mortar were decreased. Yet, nano-SiO(2) could help produce hydration crystals, which implies that the addition of nano-SiO(2) to mortar can improve the influence of sludge/fly ash on the development of the early strength of the mortar.
authors.affiliation: Department of Civil and Ecological Engineering, I-Shou University, Dashu Township, Kaohsiung County, Taiwan, ROC.
authors.forename: D F
authors.initials: DF
authors.lastname: Lin
authors.forename: K L
authors.initials: KL
authors.lastname: Lin
authors.forename: W C
authors.initials: WC
authors.lastname: Chang
authors.forename: H L
authors.initials: HL
authors.lastname: Luo
authors.forename: M Q
authors.initials: MQ
authors.lastname: Cai
mesh_terms: D002244:Carbon / Q000737:chemistry*; D060729:Coal Ash; D003247:Conservation of Natural Resources; D003252:Construction Materials; D017745:Incineration; D008854:Microscopy, Electron; D053758:Nanoparticles; D052638:Particulate Matter / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D060729:Coal Ash; D052638:Particulate Matter; D012722:Sewage; D002244:Carbon; D012822:Silicon Dioxide