SU Jie (1979-), male, Ph. D, Associate Professor. E-mail: iamsujie@163.com
The effects of strength grade, steel fiber content on the compressive strength and its scale effect of ultra-high performance concrete (UHPC) were investigated via cubic compressive strength tests on the UHPC cubic specimens with different sizes, strength grades and fiber contents. The results show that the scale effect of the cubic compressive strength becomes more obvious with the increase of strength grade. The scale effect of the cubic compressive strength of the plain UHPC specimen with a strength grade R160 is 1.72 times greater than that of the specimen with a strength grade of R120. The content of steel fiber has an effect on the scale effect of the cubic compressive strength. The greater the content of steel fiber is, the more pronounced the scale effect will be. The scale effect on the cubic compressive strength of specimens with a fiber content of 3% is 46% greater than that of the specimens without steel fiber reinforcement. The size conversion factors for cubic compressive strength of the UHPC with different strength grade sand the calculation formulas for the scale effect law of the cubic compressive strength of the UHPC are proposed. The proposed formulas can be used to analyze the cubic compressive strength of the UHPC.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |