| Autor: |
NING Fengwei, CAI Yuebo, DING Jiantong, ZHANG Feng, BAI Yin, CHEN Bo |
| Zdroj: |
New Building Materials / Xinxing Jianzhu Cailiao; 2020, Vol. 47 Issue 1, p1-26, 6p |
| Abstrakt: |
Low compressive strength and poor durability were typical characteristics of ordinary C25 shotcrete, which made it difficult to meet the support requirement of underground openings in high ground stress conditions. In order to solve these problems, the mix design of C50 shotcrete was carried out by reducing water-binder ratio, adding active admixture and introducing 2%~6% of calcium oxide expansive agent. Mechanical properties, deformation and durability of C50 shotcrete were also evaluated. The results indicated that C50 compensating-shrinkage shotcrete could be made by using 10% of silica fume, 2%~4% of calcium oxide expansive agent, water-binder ratio of 0.35 and alkali-free accelerator whose compressive strength ratio surpassed 120%. The shotcrete had higher compactness and durability. The porosity was only 44%~50% of that of ordinary C25 shotcrete. The diameters of around 80% of pores were less than 50 nm. Besides, the impermeability grade and freeze resistance grade surpassed W25 and F300, respectively. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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