Control of Interface Structure between Cement Paste and Waste-Derived Aggregates
| Project/Area Number |
11650472
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
土木材料・力学一般
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| Research Institution | Kanazawa Institute of Technology |
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Principal Investigator |
UCHIKAWA Hiroshi Kanazawa Institute of Technology, Department of Engineering, Professor, 工学部, 教授 (40308573)
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| Co-Investigator(Kenkyū-buntansha) |
TSUYUMOTO Isao Kanazawa Institute of Technology, Department of Engineering, Assistant Professor, 工学部, 講師 (60282571)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2000: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1999: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | HVRWC / waste-derived aggregate / compressive strength / transition zone / Ecocement / hardened structure / adhesive strength / crushing value |
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| Research Abstract |
High-volume recycled waste concrete (HVRWC) was prepared by utilizing waste-derived aggregates such as sintered sewage sludge, incineration ash of urban refuse, sintered coal ash and glass cutlet, and compared with the ordinary concrete from natural aggregates. Ecocement from incineration ash of urban refuse was also used instead of normal Portland cement (NPC).
The compressive strength of concrete was decreased with increasing the mixing ratio of waste-derived aggregates. This is attributed to the low strength of waste-derived aggregates owing to coarse pores and the low adhesive strength between cement paste and the aggregates. The HVRWC including 631kg/m3 of waste-derived aggregates showed high strength more than 40 N/mm2 at the age of 91 days, which can be applied to construction materials.
The hydration in HVRWC proceeded similarly to that of natural aggregates, and no mischief owing to wastederived materials was observed. The combined use of blast-furnace slug and fly ash allowed the densification of concrete textures with age, by consuming Ca(OH)2 and promoting the formation of C-S-H.The hardened structure of HVRWC did not show great difference from that of the natural aggregates. The durability was comparable, and the elution of the harmful species from the concrete was not observed.
SEM and EPMA observations indicated that the transition zone did not form at W/C=0.5 when Ecocement was used. The contact between Ecocement paste and aggregates was in better conditions than the NPC.The sintered sewage sludge showed lower adhesive strength and rather higher porosity than the standard sand aggregate, which is ascribable to the smoothness on the surface of the aggregate. It was suggested that the interface structure between cement paste and waste-derived aggregate could be controlled by using Ca(OH)2-consuming and polyhydrates-forming cement such as Ecocement.
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Report
(3 results)
Research Products
(23 results)
