LIU Qiongwei (1996-), male, Master candidate. E-mail: 854636505@qq.com
Direct tensile tests were carried out on three types of ultra-high performance concrete (UHPC) specimens with different thicknesses of arc-shaped dog bone shape, and the relationship among axial tensile stress, strain, and crack of UHPC was analyzed. The results show that the tensile strength of UHPC increases slightly, the ability to limit crack development increases, the strain capacity decreases significantly, and the strain softening rate increases as the specimen thickness decreases from 100 mm to 30 mm. When the crack width is less than 0.2 mm, the post-crack stress of UHPC increases slightly. After the main crack forms, the crack development rate and the post-crack stress decline rate increase correspondingly. The tensile strain value is fitted from the main crack width, and it is indicated that the main crack development process of UHPC specimen be in reasonable agreement with the strain softening stage.
| 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 |