葛其荣¹  郑子祥²  高  翔³  李秋生⁴  卢安琪⁵  朱  强⁶

（1 宁波市白溪水库建设指挥部 315606； 2 国家电力公司华东勘测设计研究院； 3 上海勘测设计研究院； 4 水利水电第十二工程局第一分局； 5 水利部南京水利科学研究院； 6 甘肃省水科所）

 

[提要]  白溪水库二期面板工作条件比较严酷，为了提高面板的质量和耐久性，进行了二期面板聚丙烯纤维混凝土的试验研究。研究表明，混凝土加入0. 9kg/m3的聚丙烯纤维后，可以明显改善混凝土的变形性能，表现为减少混凝土干缩和抑制裂缝发生，增加极限拉伸率，降低弹性模量，大大提高了弯曲韧性，混凝土的耐久性显著提高，抗冻标号从Fl00提高到F200。加速老化试验证明，紫外线照射对混凝土内部的纤维影响仅发生在浅表层3～4mm内，对混凝土整体性能没有影响。聚丙烯纤维混凝土施工工艺与普通混凝土基本相同。采用适当的拌和方法、控制适宜的坍落度、加强振捣和收面工序，可以保证面板的施工质量。混凝土造价仅增加约50元/ffl3。与取得的效益相比，是十分经济的。
[关键词]  聚丙烯  纤维  混凝土  变形性能  耐久性

The working condition of second stage deck of the Baixi Reservoir is very adverse. To enhance the quality and durability of the deck, an experimental study on the polypropylene fiber reinforced concrete( PPFRC) for the deck of second stage is made. The study shows that with 0.9kg/m3 fiber, the deformation performance of the concrete can be improved significantly. The dry shrinkage and cracking of concrete are reduced, the maximum tension strain is increased, the elastic modulus is lowered and the bend toughness is raised. The durability of the concrete is also improved. The frost-resistance label increases from Fl00 to F200. Accelerated aging test proves that the effect of ultraviolent radiation on the performance of fibers inside the concrete is valid only at a thin layer with thickness of 3 to 4mm. There is no influence on the integrated performance of the concrete. The construction method of PPFRC is basically the same with that of the conventional concrete. The construction quality can be ensured if adopting proper mixing procedure, controlling the concrete slump to an appropriate level and improving the vibration and finishing. The added cost for PPFRC is only 50 yuan/m3. Comparing to the benefit,it is a quite economic solution.
Keywords:  polypropylene; fiber; concrete; deformation performance; durability