PP单丝纤维自密实混凝土强度与抗渗性能

Strength Properties and Permeability of Polypropylene Monofilament Fiber Reinforced Self-Compacting Concrete

采用力学试验、渗水标号试验、渗水高度试验和氯离子渗透试验研究了聚丙烯(PP)单丝纤维自密实混凝土强度、抗渗性能,通过扫描电镜观察了纤维自密实混凝土的微观结构,从材料的组成结构和断裂力学原理上分析了PP单丝纤维对自密实混凝土强度以及抗渗性能的影响机理。结果表明:当PP单丝纤维自密实混凝土体积掺量不超过0.15%时,PP纤维自密实混凝土具有较好的抗渗性能,渗水标号大于S 35;PP单丝纤维体积掺量不超过0.1%时,自密实混凝土的强度和抗水渗性能随着纤维体积掺量的增加而提高,电通量有所增加,而当体积掺量超过0.15%后,强度仍然有增长,电通量急剧增加;与普通自密实混凝土相比,0.10%单丝PP纤维自密实混凝土具有较好的强度特性和抗渗性能,28d弯拉强度提高16.4%,28d劈裂强度提高13.4%,56d氯离子渗透电通量为919C,渗水高度减少57%。

Strength properties and permeability of the self-compacting concrete, which are reinforced with polypropylene monofilament fiber of different volume fractions, were investigated through mechanical test, water permeability test and chloride permeability test （chloride penetrability based on charge passed）. Then, the microstructure of the polypropylene fiber reinforced self-compacting concrete （PFRSCC） was observed through scanning electronic microscope. The impact of polypropylene fiber on strength properties and permeability was analyzed according to the material composition and fracture theory. The results show that： 1） PFRSCC, when the volume fraction of polypropylene monofilament fiber is less than 0.15%, has good impermeability, characterized with high impermeability mark OS 35, based on Chinese Standard Test Method T 0568-2005） ; 2） When the volume fraction of polypropylene monofilament fiber is less than 0. 10%, PFRSCC＇ s strength properties and water impermeability increase with the addition of polypropylene fiber, and electric flux increases slightly. Whilse when the volume fraction of polypropylenefiber is higher than 0.15%, e concrete, PFRSCC, 0. 10% increase in splitting strength about 919 C at 56 d. lectric flux increases dramatic polypropylene fiber has 16.4 and 57% decrease in permeat ally; 3） Compared with ordinary self-compacting increase in flexural tensile strength, 13.4% ion depth, and chloride ion penetrability is low,