管片内施工工艺翻译-中英对照
我公司目前施工的穗莞深城际轨道项目的管片预制全部添加采用聚丙烯纤维混凝土（共8000环，约140000立方米）；另外，我公司施工的天津海河盾构项目的管片生产也添加了聚丙烯纤维。
为减少管片制作过程中开裂，并提高结构耐火能力，防止火灾情况下，管片混凝土块爆裂掉块，每方混凝土内掺网状聚丙烯纤维1.5kg。纤维性能指标如下表所示：
聚丙烯纤维指标表
项目 指标 项目 指标
抗拉强度 ≥500MPa 熔点 160¬170℃
弹性模量 ＞3500MPa 抗酸碱性 强
电阻 1.2GΩ 直径 ≤100μm
韧性指数 I5≥3.0 材质 100%聚丙烯，
不含再生链烯烃
比重 0.91g/cm3
标准 符合CECS38:2004纤维
混凝土结构技术规程
长度 12¬19mm
施工工艺流程：
a. 管片混凝土采用专用搅拌机生产，纤维随骨料沿上料输送带一起投入混凝土搅拌机，每盘掺入3 kg；
b. 为确保纤维在拌合物中分散均匀，不产生结团，先将纤维、水泥、粗细骨料干拌1-2分钟；
c. 加水湿拌，较普通混凝土规定的搅拌时间适当延长40-60s，以确保纤维在混凝土拌合物中分散均匀，同时确保混凝土坍落度满足设计要求和规范规定；
d. 纤维混凝土浇筑方法应保证纤维的分布均匀和结构的连续性，振捣时间较普通混凝土延长20s左右至无可见空洞为止；
e. 混凝土接近初凝时（表面比较钝化时）方可进行抹面，不宜使用过于毛糙的抹面工具，抹面应光滑，但不得加水，不得抹面次数过多。
Construction Technology by adding polypropylene fiber into the segment
The prefabricated segments of the construction project of our company in Sueiwanshencheng Tunnel Project all applies polypropylene fiber concrete (8000 rings in total, which is about 140000 cubic meters). In addition, the prefabricated segments production of our company in Tianjin Meihe Tunnel Shield Project has also added the polypropylene fiber.
In order to reduce the craze in production process, and improve the performance of fire resistance of structure, and under the condition of fire prevention, segment of concrete blocks, the concrete of each cubic meter shall be mixed with 1.5 kg mesh polypropylene fiber. Fiber performance indicators are as follows:
Polypropylene fiber index table
Item Index Item Index
Tensile strength ≥500MPa Fusion point 160¬170℃
Elastic modulus ＞3500MPa Acid and alkaline resistance Strong
Resistance 1.2GΩ Diameter ≤100μm
Toughness index I5≥3.0 Material 100% polypropylene;
no regeneration olefins chain content;
Specific gravity 0.91g/cm3
Standard Meet with the standard of CECS38:2004 Technical specification for fiber concrete structures
Length 12¬19mm
Construction process:
A. Segment concrete applies special mixer in production; fibers shall be dumped into the concrete mixer together with aggregate on feeding conveyor belt; each disc mixed with 3 kg;
B. To ensure that the fiber is evenly distributed in the mixer without clot, mixes the fibers, cement, coarse and fine aggregate for 1-2 minutes without water;
C. Add water to the mixer, mixes for more 40 to 60 minutes than normal concrete mixing time, so as to ensure that the fiber is evenly distributed in concrete mixing. At the same time, ensure concrete slump meets the design requirements and regulations;
D. Fiber concrete casting method shall ensure the uniformity distribution of fibers and continuity of structure; the vibrating time shall have more 20 minutes than ordinary concrete until no empty hole were found;
E. Carry out the plastering work when concrete close to initial setting (concrete surface is inactivation); do not use rough plaster tools; plaster surface shall be smooth; do not add water and do not plaster for too many times.
2013.10.22