纤维增强活性粉末混凝土高温力学性能的实验研究

Research on Mechanical Performance and Microstructure of Fiber Reinforced Active Powder Concrete at High Temperature

研究了钢纤维、聚丙烯纤维和PVA纤维的不同掺量以及纤维复掺在90℃、200℃和400℃高温养护时活性粉末混凝土的力学性能和微观结构。结果表明,200℃高温养护,单掺钢纤维时,RPC的抗折强度与90℃的相近,但抗压强度提高,达210.2MPa;单掺聚丙烯纤维时,由于其高温熔解,形成三维网络结构,与RPC融为一体,抗压强度显著提高,当掺量为1.5%(体积分数)时,强度达242.6MPa。纤维复掺时抗折强度与钢纤维相近,但抗压强度有所提高,200℃养护时达265MPa。400℃养护时,随水胶比降低,强度进一步增大,当水胶比为0.12时,抗压强度达333.4MPa。

Mechanical performance and microstructure of fiber reinforced active powder concrete with different contents of steel fiber, polypropylene fiber and PVA fiber in high temperature curing at 90℃, 200℃ and 400℃ are studied, different fibers are mixed. The results show that the flexural strengths at 200℃ curing are similar to them at 90℃ curing with steel fiber only, but compressive strength increases to 210. 2MPa For polypropylene fiber, compres- sive strength increases remarkably because it melts in high temperature and shapes three-dimensional net structure,and reaches 242. 6MPa when 1.5 % of volume content is mixed. Flexural strength is similar to steel fiber which is mixed when different fibers are mixed, but compressive strength is increased to 265 MPa. The strength at 400℃ is further increased with the W/B decreased, the compressive strength is 333. 4MPa when W/B is 0. 12.