title: Characterization of eco-cement paste produced from waste sludges.
abstract: In this study, marble sludge, sewage sludge, drinking water treatment plant sludge, and basic oxygen furnace sludge were used as replacements for limestone, sand, clay, and iron slag, respectively, as the raw materials for the production of cement in order to produce eco-cement. It was found that it is feasible to use marble sludge to replace up to 50% of the limestone and also that other materials can serve as total replacements for the raw materials typically used in the production of cement. The major components of Portland cement were all found in eco-cement clinkers. The eco-cement was confirmed to produce calcium hydroxide and calcium silicate hydrates during the hydration process, increasing densification with the curing age. The compressive strength (S(c)) and microstructural evaluations conducted at 28 d revealed the usefulness of eco-cement. It was observed that the S(c) data correlated linearly with the pore volume (P) data at 28 d. The proposed model equation could be represented as S(c)=178-461P (correlation coefficient, R(2)=0.96). Two parameters, the large capillary pore volume and the medium capillary pore volume, were evaluated using multiple regression analysis.
authors.affiliation: Graduate Institute of Environmental Engineering, National Central University, No. 300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan.
authors.forename: Chi-Liang
authors.initials: CL
authors.lastname: Yen
authors.forename: Dyi-Hwa
authors.initials: DH
authors.lastname: Tseng
authors.forename: Tung-Tsan
authors.initials: TT
authors.lastname: Lin
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D002119:Calcium Carbonate / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D002126:Calcium Hydroxide / Q000737:chemistry; D000077215:Clay; D019245:Compressive Strength; D003247:Conservation of Natural Resources / Q000379:methods; D003252:Construction Materials / Q000032:analysis*; D007220:Industrial Waste / Q000032:analysis*; D008422:Materials Testing; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D017610:Calcium Compounds; D007220:Industrial Waste; D012722:Sewage; D017640:Silicates; D012822:Silicon Dioxide; D002119:Calcium Carbonate; D002126:Calcium Hydroxide; C031293:calcium silicate; D000077215:Clay