Study on Durability of Controlled Low Strength Materials with Circulating Fluidized Bed Combustion Ash

• Main Authors: PENG,CHI-CHENG, 彭繼正
• Other Authors: SHIH,CHENG-YUAN
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/61210276923935491230

碩士 === 明志科技大學 === 化學工程系碩士班 === 104 === Electricity and Steel are the most important industry in economic development. However, pollutants generating during manufacturing process, if such industry wastes are not handled properly, environmental pollution and healthy problem will take place. In this study the Circulating Fluidized Bed Combustion (CFBC) ash of Formosa Plastics, F type fly ash of Taiwan Power Company, slag powder of CHC Resources Corporation and cement are added as the binder, and slag of China Steel Corporation and CFBC hydration ash are reused as the Filler. Research on durability of Controlled Low Strength Material (CLSM) for underground pipe engineering, nine mixtures of design for Slump, Ball Drop, Length Change, Compressive Strength and Sulfate Attack, verifying the CLSM engineering properties, and analyzing microstructure by SEM/EDS, XRD, TGA/DSC, FTIR. Test results are presented as follows: (1)The slump of all mixtures comply with specification, under coarse aggregate to fine aggregate of 1:1 condition. (2)Ball Drop of most binder ratios achieve criteria, except for S4M2F15C25. (3)28-day Compressive strength of all samples are between 1.96 MPa to 8.83 MPa. Moreover, CFBC ash increasing as compressive strength decreasing. (4)After sulfate attack all of the sample strength were reduced, but Compressive Strength still comply with specification. (5)TGA/DSC and FTIR show that CLSM will not generate the new hydrates under different kinds of binder ratio mixtures. In TGA/DSC peak at 90℃ and 140℃ which are dehydration of AFt and gypsum. Weight loss the range of 150℃ to 700℃ is due to dehydration of C-S-H colloid. After 700℃ calcium carbonate is decomposed into CaO and O2. In FTIR the vibrations which in the region1600–3700 cm-1 are assigned to the presence of the H2O and OH stretching bands. Peak 3440 cm-1 is about water molecules hydrogen bonding to the surface of the oxygen. Peak 1640 cm-1 is about the mode of water bends. Peak 1100 cm-1 to 1500 cm-1 is about vibrations of S-O. Peak 670 cm-1 is assigned to the presence of SiO6 bends, which also proves the emergence of the hydration of C-S-H gel. The peak at 850 cm-1 with AlO6, which are attributed to the formation of AFt. The characteristic peaks of carbonates are 1430 cm-1 C-O stretching vibration peak. (6)XRD show that the most obvious peak is gypsum, secondly is AFt, C-S-H, and CH. In addition AFt, C-S-H, CH, and few undissolved fly ash in SEM/EDS.