Reasonable evaluation of the bond performance between steel bars and concrete has important theoretical and practical value for reinforced concrete structural design and seismic analysis. The stress (τ) – strain (ε) formula is corrected based on a pull-out test, and the load (F) – deflection (w) curves are analyzed according to the change of stiffness before and after crack appearance based on a beam test, and new estimation formulas are given. At the same time, the bond properties are compared between all-lightweight shale ceramsite concrete (ALWSCC) and normal weight concrete (NWC). The results show that the bond property of ALWSCC is better than NWC. The bond stresses of pull-out specimens and beam specimens are the same or similar under equal conditions, but the ultimate load (F0) of the former is about 3.66 times that of the latter, the peak slip (S0) of the latter is 4.80 times that of the former, and the latter has significant splitting or pull-out failure characteristics. The peak slip (S0) in this paper is larger than that in the related literature, where the pull-out specimens are no more than 10 mm, and are generally less than 2 mm, while the beam specimens are not more than 3 mm, with the others generally around 1 mm. The research results have reference values and guiding significance for similar experimental research and engineering practice.

High-strength concrete (HSC) reinforced with steel fibre (SF) and carbon nanotube (HSCRSC) is a new type of high-strength composite concrete with good fluidity, high strength, toughness, durability and other remarkable advantages. HSCRSC can be widely used in underground structures, such as wellbores. In this study, HSCs ranging from 70 to 100 MPa were designed, and the effects of fibre on the performance of the HSCs were compared and analysed through single-doped and doublemixed SF and multi-walled carbon nanotubes. Results showed that the fibre effectively improved the uniaxial and multiaxial compressive strengths and durability of HSCs and changed the failure mode from brittle to ductile, especially in the case of multiaxial compression failure. HSCs remained intact, but the plain concrete specimens had fractured forms, such as flakes, columns and layers. Moreover, the ultimate strength of the biaxial compression was between 1.10 and 1.39 times higher than that of the uniaxial compression, satisfying the Kufer-Gerstle criterion. The ultimate strength of the triaxial compression was between 1.24 and 2.55 times higher than that of the uniaxial compression, adhering to the Willam-Warnke meridian criterion. The modified B3 model met the prediction accuracy of shrinkage and creep for HSC and surpassed the biaxial and triaxial compression ultimate strength models provided in this study. The absolute value of the relative error was less than 6%, indicating that the model and test data were reliable. All test results showed that HSCRSC exhibited satisfactory comprehensive performance.