中文摘要：

通过纳米SiO2/纤维增强混凝土高温后抗压、劈拉和抗折试验,探讨了钢纤维和纳米SiO2对混凝土在不同高温后强度及变形性能的影响.结果表明：随温度升高,抗压、劈拉和抗折强度均减小;复合掺加纤维和纳米材料抗压强度及变形性能优于单掺纤维或纳米材料,随钢纤维掺量增大抗压、劈拉和抗折强度呈增大趋势,掺入纳米SiO2各强度指标均有改善,劈拉和抗折破坏形态得到改善,由脆性破坏转变为塑性破坏,变形曲线丰满度提高,下降段平缓.

英文摘要：

Compression, splitting and bending mechanical experiments were carried out to study the mechanical and deformation properties offiber and nanomaterials reinforced concrete （FNRC） after its exposure to high temperature. Based on the experimental observation, a systematical analysis is made to investigate how the content of nanomaterials and steel fiber affect the compressive, splitting and flexural strength and splitting and flexural deformation after being subjected to high temperature. Test data indicates that high temperature causes significant deterioration to compressive, splitting and flexural properties of FNRC, and both nanomaterials and steel fiber could effectively improve the strength and deformation of FNRC. With the increase of fiber content, the compressive, splitting and flexural strength show a trend of increase. Adding nano-SiO2 into concrete can improve the mechanical properties and deformation. Both steel fiber and nanomaterials can improve the failure mode of splitting and bending, by brittle failure into plastic failure and the fullness of deformation curve.