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• The long-term bond durability of GFRP-RC beam structure is investigated; • The mBPE model was modified to consider the splitting of concrete cover; • The effect of working crack on structural bond performance is re recognized; • The long-term bond behavior prediction model of GFRP-RC beam was proposed. This paper investigates the long-term bond-slip behavior of GFRP (glass fiber reinforced polymer)-RC (reinforced concrete) beams. The specimens used in the bond test have been exposed to alkaline accelerated corrosion solution for eight years. In order to more accurately explore the long-term degradation law of the GFRP-RC beam, the factors of sustained load, pre-crack, and specimen form are also considered in this test. The experimental results show that the long-term degradation efficiency of specimens with pre-cracks increases significantly. The interfacial fracture energy and maximum bond strength at fracture failure are reduced by 16% and 23%, respectively. Although the overall bond performance of GFRP-RC beams will deteriorate with service time, the structure usually enters the slow degradation stage. However, the pre-cracks inhibit the arrival of this stage so that the structure will suffer more damage. In order to more intuitively evaluate the safety level of the residual bond performance of the structure in the current state, the long-term degradation prediction model of the GFRP-RC beam is established. [ABSTRACT FROM AUTHOR]

• The numerical form of the exact Kramers-Kronig relation is employed to construct master curve of storage modulus. • The analytical expression of the continuous relaxation spectrum is derived from the master curve model of storage modulus. • The continuous relaxation spectrum is determined based on the same model parameters of the storage modulus models. • The generated continuous relaxation spectrums are consistent with the LVE theory and physical causality. The relaxation spectrum plays a vital role in the study of linear viscoelastic (LVE) properties of asphalt materials; however, the current developed using methods are not accurate enough to characterize the LVE properties of asphalt materials. This paper aims to develop an improved method to determine the continuous relaxation spectrum of asphalt materials. A modified Christensen–Anderson–Marasteanu (CAM) model is first selected as the master curve model of the storage modulus, upon which the master curve model of loss modulus is then established using the numerical form of the exact Kramers-Kronig relation between the storage modulus and loss modulus. According to LVE conversions between the relaxation spectrum and storage modulus, the model of the continuous relaxation spectrum is subsequently derived and finally determined based on the same model parameters of the storage modulus and loss modulus models. This study demonstrates that the relaxation spectrum of both mixtures and binders constructed by the proposed method is compliant with LVE theory and physical causality. The generated relaxation spectrum is verified to be accurate enough to compare the storage modulus and loss modulus values recalculated by the relaxation spectrum and the corresponding values predicted by master curve models. The results also show that the approximate Kramers-Kronig relation between the storage modulus and loss modulus cannot be used to establish the relaxation spectrum of asphalt materials, especially for asphalt binders. In addition, the generated relaxation spectrum was utilized to construct the relaxation modulus of mixtures and to develop the stiffness modulus of binders, respectively. Since the relaxation modulus and creep stiffness are determined from the relaxation spectrum, both are consistent with LVE theory and physical causality. [ABSTRACT FROM AUTHOR]