Nanomaterials (nano powdered rubber VP401, VP501 and sepiolite and CaCo 3 composites) were selected to improve the high-temperature and low-temperature performance of asphalt binder. Nanomaterial modified asphalt was prepared using the high shear machine. Laboratory experiments of asphalt binder and asphalt mixture were conducted to evaluate the properties of modified asphalt binder, including the penetration, ductility, softening point, viscosity, and etc. Also, asphalt mixture tests were carried out, such as the cleavage strength test, resilient modulus test, rutting test, water stability test and etc. Based on the test results, asphalt binder modified by 1% nano powdered rubber VP401 has better performance resistance to low temperature crack and rutting, compared to other nanomaterial modified asphalt binder.

The digital image processing technique was applied to analyze and evaluate the coarse aggregate orientation property in asphalt mixture specimens. Specimens produced by Marshall compaction, vibratory compaction, gyratory compaction, and roller compaction were separately evaluated and compared with the core samples drilled from real asphalt pavement. The quantitative index named maximum likelihood angle (MLA) was developed for statistical analysis on the coarse aggregate orientation. It is found that the coarse aggregate orientation properties of the specimens using different compaction methods have great differences, the specimens produced by laboratory Marshall compaction method has no statistical discipline, the specimen produced by laboratory roller compaction method has the best similarity property with the real asphalt pavement. The results indicate that the MLA is an effective index in evaluating the aggregate orientation, and the roller compaction method should be the first choice in laboratory asphalt mixes specimen preparation.

In order to study viscoelastic properties of asphalt mixture, an advanced Shear Rheometer is used. The continuous dynamic frequency scanning test is carried out, which can get full-temperature-full-frequency master curve of asphalt mixture by the time-temperature equivalence principle. The CAM model acts as the rheological model for studying viscoelastic properties of asphalt mixture, because CAM model’s parameters have clear physical meaning. Then viscoelastic properties of asphalt mixture are studied basing on the four equations of CAM model in the full-temperature-full-frequency range.

Self-compacting concrete-filled steel tube is different from ordinary self-compacting concrete in many aspects. According to the demands of on-site construction conditions and construction technology of continuous pumping lift-up method for the project of Huaxi No.1 steel tube arch bridge, property requirements of self-compacting concrete filled steel tube were proposed in this paper. By using the preparation techniques such as optimization of basic parameters of concrete mix proportion, admixture composition and mineral admixture addition, self-compacting concrete filled steel tube was prepared with the properties such as initial slump more than 24cm, initial slump flow above 650mm, T50 between 5s and 15s, no slump loss for 4h, no bleeding, strength grade above C60 and shrinkage-compensation etc. It was applied in the steel tube arch bridge project successfully using the construction technology of pumping lift-up method.