PPFRCP灌浆材料的优化选型及工作性能研究

Research on the Optimal Selection and Workability of PPFRCP as a Grouting Material

选取了3mm、6mm、9mm和12mm 4种长度的聚丙烯纤维,通过不同纤维掺量PPFRCP的静力和动力性能对比,优选出最佳纤维长度后,考察纤维体积掺量对PPFRCP工作性能指标的影响及其规律。结果表明,在固定纤维掺量的情况下,纤维长9mm时PPFRCP的早期抗压强度、抗折强度和冲击韧性均达到最大,且相对于普通水泥净浆的提高幅度十分显著。随着纤维掺量的增加,浆体的流动度增大、坍落直径降低,流动度、坍落直径与纤维掺量之间存在显著的线性相关性。研究结果还表明,仅采用规范中的流动度单一指标评价PPFRCP的工作性能并不可靠,应将其结合坍落直径进行综合评判。

Through a comparison analysis among the polypropylene fibers with the length of 3mm,6mm,9mm and12 mm respectively,the optimal length of polypropylene fiber was sorted out according to the static and dynamic characteristics of PPFRCP with different mixing amounts of fiber,and the influence of mixing amounts on the workability of PPFRCP was studied.The experimental results showed that with a certain mixing amount of fiber,the PPFRCP with the fiber length of 9mm was the highest early compressive strength,early flexural strength and impact toughness,and the improvements are quite significant comparing with those of ordinary cement paste.As the increasing of mixing amount of fiber,the fluidity of the seriflux increased and the slump diameter decreased,and there existed significant linear correlation between the fluidity,the slump diameter and the mixing amount of fiber.It also shows that it is not reliable to evaluate the workability of PPFRCP only according to fluidity referred in specification,and the slump diameter should also be introduced in such an evaluation.