| dc.description.abstract | This research investigates on the feasibility of replacing the cement raw materials with co-fired biomass ash by using laboratory scale fixed-bed furnace and rotary kiln system. The physical, chemical and mechanical characteristics of the cement clinker manufactured by different co-fired ash addition were controlled the cement modulus, heating rate, sintered temperature, and sintered time.
The fixed-bed experimental results showed that the compressive strength of cement clinker manufactured by cement raw materials were 75.48 kgf/cm2 (3 days), 134.91 kgf/cm2 (7 days), and 216.42 kgf/cm2 (28 days). However, compressive strengths of eco-cement produced by different co-fired ash addition were lower than that of the cement clinker. Only one eco-cement (produced by KYP BA) compressive strengths were 101.16 kgf/cm2 (3 days), 130.65 kgf/cm2 (7 days), and 230.00 kgf/cm2 (28 days), respectively, higher than that of cement clinker.
To further assess the effect of eco-cement sintered by rotary kiln system, the results indicated that the f-CaO content of the eco-cement clinker was decreased from 1.5% to 1.0% resulted in applying the rotary kiln system. For the setting time, the initial and final setting time of the eco-cement sintered by rotary kiln system were approximately ranged from 150 minutes to 250 minutes. Comparing with fixed-bed furnace, it could reduce 50 minutes setting time. In the case of the compressive strength of cement clinker produced by rotary kiln system, the compressive strengths were 120.00 kgf/cm2 (3 days), 191.76 kgf/cm2 (7 days), and 273.33 kgf/cm2 (28 days), respectively. However, the compressive strengths of eco-cement sintered by KYP BA were in compliant with CNS 61 standard criteria which there were 168.32 kgf/cm2 (3 days), 195.03 kgf/cm2 (7 days), and 263.87 kgf/cm2 (28 days). It implied that the main mineral composition of the cement clinker was formed by rotary kiln system.
According to the hydration results of clinkers, the main hydration products C-H and C-S-H gel could be observed at the early curing stage. The C-H and C-S-H gel were significantly increased with the curing age increasing. Based on the XRD, FTIR, and SEM analysis results, it can find out the above experimental results were consistent with the trends in compressive strength increasing. Overall, the relevant results of this research has proved the feasibility of eco-cement manufactured from co-fired biomass ash and cement raw materials, but also can provide useful information for the development of related technologies and policy formulation in eco-cement manufacturing. | en_US |