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To investigate the temperature dependence of the modulus of LSAM-50 flexible base asphalt pavement (LSAM-50 pavement) materials, specifically SMA-13, AC-20, and LSAM-50. The effects of temperature on the modulus of LSAM-50 pavement materials were investigated, and a temperature-dependent model of resilient modulus was established. A dynamic modulus master curve was constructed based on a generalized logarithmic Sigmoidal model. The correlation between the resilient modulus and dynamic modulus was studied, and a multiple linear regression model was developed to describe the relationship between the dynamic modulus and resilient modulus, temperature, and loading frequency. The results show that the resilient modulus and dynamic modulus gradually decrease with the increase in temperature and then tend to stabilize. The resilient modulus of LSAM-50 is higher than that of SMA-13 and AC-20 in the entire temperature range, and the dynamic modulus of LSAM-50 is higher than that of SMA-13 and AC-20 in the high-temperature range. The correlation coefficients (R2) of the established resilient modulus and dynamic modulus estimation models are greater than 0.97 and 0.94, respectively.

The actual lifetimes of many highways are lower than that expected based on the initial pavement design, which brings increasingly prohibitive costs of pavement maintenance and repair. Although many works have been done, the real service lifetimes are still disappointing, and the researchers are also trying their best to increase the projects’ life span. In this study, to comprehensively predict the durability and lifetime of newly designed asphalt mixture structures, an asphalt pavement project consisting of three hot mix asphalt (HMA) mixtures were evaluated. The mixtures were constructed in the pavement project of the Weiwu expressway in Gansu Province. Pavement properties of the asphalt mixtures, rutting and temperature fatigue factors of the dynamic modulus are discussed. The fatigue resistance is supposed to improve on increasing the vehicles’ speed below the freezing point, which may be more suitable for applications in expressways. Meanwhile, the lifetime is measured according to the number of fatigue axle loads calculated, which were corrected between the specimens in the lab and the field core samples. Durability analysis prediction can be obtained based on the fatigue lifetime predictive model accordingly, which can provide more information about the fatigue lifetime and the rehabilitation planning of existing pavements in the future accordingly.

This study delves into self-compacting concrete (SCC), exploring the impact of incorporating varying volumes of basalt fibers, with a specific focus on frost resistance. We investigated four SCC mixtures: SCCBF0% (no fibers), SCCBF0.1%, SCCBF0.2%, and SCCBF0.3%, representing different proportions of basalt fibers in the concrete volume. Frost resistance was rigorously assessed through 50 freezing–thawing cycles, adhering to ASTM C666/C 666M-3 standards. After each 10 cycles, we measured key properties, including weight loss, density, ultrasonic pulse velocity, and compressive strength. We also evaluated the dynamic modulus of elasticity, relative dynamic modulus elasticity, and durability factor. Our findings unveil a compelling narrative. The incorporation of basalt fibers proved transformative, significantly enhancing the concrete's overall strength and resilience, particularly against freezing–thawing cycles. Notably, introducing 0.3% basalt fiber volume led to remarkable improvements in frost durability within the SCC mixtures. In summary, our research unequivocally underscores the overwhelmingly positive influence of basalt fibers on SCC, particularly in bolstering frost resistance, durability, and strength. These findings hold significant implications for engineers and practitioners working in cold climates, where these attributes are paramount. Furthermore, we advocate for additional research to delve into the long-term performance and economic feasibility of integrating basalt fibers into SCC, especially for applications demanding robust frost resistance. This study not only paves the way for concrete technology innovation but also extends its relevance beyond frost resistance, promising a broader horizon of possibilities.

Scrap tire rubber and nylon fiber are waste materials that could potentially be recycled and used to improve the mechanical properties of asphalt pavement. The objective of this research was to investigate the properties of scrap tire rubber and nylon fiber (R-F) modified warm mix asphalt mixture (WMA). The high-temperature performance was estimated by the Hamburg wheel-tracking testing (HWTT) device. The low-temperature cracking performance was evaluated by the disk-shaped compact tension (DCT) test and the indirect tensile strength (IDT) test. The stress and strain relationship was assessed by the dynamic modulus test at various temperatures and frequencies. The extracted asphalt binder was evaluated by the dynamic shear rheometer (DSR). Pavement distresses were predicted by pavement mechanistic-empirical (M-E) analysis. The test results showed that: (1) The R-F modified WMA had better high-temperature rutting performance. The dynamic modulus of conventional hot mix asphalt mixture (HMA) was 21.8%~103% lower than R-F modified WMA at high temperatures. The wheel passes and stripping point of R-F modified WMA were 2.17 and 5.8 times higher than those of conventional HMA, respectively. Moreover, the R-F modified warm mix asphalt had a higher rutting index than the original asphalt. (2) R-F modified WMA had better cracking resistance at a low temperature. The failure energy of the R-F modified WMA was 24.3% higher than the conventional HMA, and the fracture energy of the R-F modified WMA was 7.7% higher than the conventional HMA. (3) The pavement distress prediction results showed the same trend compared with the laboratory testing performance in that the R-F modified WMA helped to improve the IRI, AC cracking, and rutting performance compared with the conventional HMA. In summary, R-F modified WMA can be applied in pavement construction.

In order to accurately evaluate the bearing capacity of asphalt pavement structure, the research group, on the basis of real-time temperature data of five kinds of asphalt pavement structure in Daxin experimental road, obtain the dynamic modulus main curves of various types of pavement materials and FWD dynamic modulus of the load acting frequency through dynamic modulus research in laboratory, and determine the dynamic modulus of the pavement structure material true value. According to the principle of dynamic deflection equivalent, this paper puts forward the evaluation method of predicting the bearing capacity of asphalt pavement based on composite modulus determination, pavement structure inverse calculation and bending stiffness modulus attenuation threshold. The evaluation results of five kinds of asphalt pavement structure bearing capacity of experimental road are consistent with the actual performance, which shows that the evaluation method of bearing capacity of asphalt pavement structure based on dynamic deflection equivalent is reasonable and effective.

Waste tire rubber–soil mixtures feature low density, high energy dissipation, and low shear modulus, which are widely used in geotechnical engineering for vibration attenuation. In this study, the evolution of the small-strain stiffness characteristics of clay-rubber mixture (CRM) is investigated; a resonance column test was carried out to determine the small-strain stiffness characteristics of CRM samples with different confining pressures (σ3), rubber particle contents (Crubber), and rubber particle sizes (Drubber). The test results indicate that σ3 can promote the dynamic shear modulus (G) of CRM and restrain the damping ratio (D). The rubber particles have a great influence on both G and D. Under the same conditions, G decreases significantly with the increase in Crubber and increases slightly with the increase in Drubber, which indicates that rubber particles inhibit the development of G. D increases with the increase in Crubber and Drubber. The results show that the contact area between clay particles and rubber particles increases with the increase in Crubber, resulting in the decreases in G and D. The G–γ curves are analyzed by using the Hardin–Drnevich equation. Based on the fitting results, the maximum dynamic shear modulus (Gmax) is obtained. Therefore, the evolution of Gmax with σ3, Crubber, and Drubber are analyzed, and an equation for the Gmax of CRM considering the effects of σ3, Crubber, and Drubber is proposed. In addition, the D–γ curves can be well described by an empirical equation.

Cracks caused by environmental temperature and humidity variation are generally considered one of the most important factors causing durability deterioration of concrete structures. The seasonal or daily variation of ambient temperature and humidity can be considered periodic. The dynamic modulus of elasticity is an important parameter used to evaluate the performance of structural concrete under periodic loads. Hence, in this paper, the dynamic elastic modulus test of concrete under simulating periodic temperature-humidity variation is carried out according to monthly meteorological data of representative areas (Nanjing, China). The dynamic elastic modulus attenuation pattern and a dynamic elastic modulus degradation model of concrete under periodic temperature-humidity are investigated. The test results show that the dynamic elastic modulus of concrete decreases and tends to be stable under the action of periodic temperature-humidity. Comparative analysis shows that the two-parameter dynamic elastic modulus degradation model is more suitable for describing the dynamic elastic modulus attenuation pattern of concrete under periodic temperature-humidity action than the single-parameter one.

Construction materials, among which concrete is by far the most used, have followed a trend of continuously increasing demand in real estate. A relatively small number of research works have been published on the long-term material properties of concrete in comparison to studies reporting their findings at standard curing ages of 28 days. This is due, in part, to the length of time one must wait until the intended age of concrete is reached. The present paper contributes to filling this gap of information in terms of the strength and dynamic elastic properties of concrete. The dynamic modulus of elasticity may be used to assess the static modulus of elasticity (Young’s modulus), a key property used during the design stage of a structure, in a non-destructive manner. This paper presents the results obtained from laboratory tests on the long-term (6 years) characterization of concrete from the point of view of dynamic shear and longitudinal moduli of elasticity, dynamic Poisson’s ratio, static modulus of elasticity, compressive and tensile splitting strengths, and their change depending on the concrete strength class.

As the critical dynamic parameters for soil, an extensive examination of the dynamic elastic modulus Ed and damping ratio λ in coarse-grained soil is of significant theoretical and practical importance. Currently, there is a scarcity of experimental equipment and methods for measuring the dynamic elastic modulus and damping ratio of coarse-grained soils. Moreover, studies examining the influence of relative density on these parameters in coarse-grained soils are largely absent. To investigate the behavior of the dynamic elastic modulus and damping ratio in coarse-grained soil under varying relative densities, a number of dynamic triaxial tests were conducted on a specific coarse-grained soil using the DYNTTS type dynamic triaxial test apparatus. The findings reveal that, under various gradations, the Ed of coarse-grained soils exhibits a decreasing trend with increasing dynamic strain, a trend that intensifies with higher relative densities. Additionally, as relative density increases, the degradation rate of the dynamic shear modulus ratio Gd/Gdmax to dynamic shear strain γd curve escalates. The maximum dynamic shear modulus Gdmax rises with increasing relative density Dr, displaying a linear relationship between Gdmax and Dr. Furthermore, both the increasing rate of λ to γd curve and the maximum damping ratio λmax progressively diminish with the escalation of relative density Dr. Notably, the maximum damping ratio has a power function relationship with the relative density.

The relationship between the static and dynamic elastic modulus in rock materials has been frequently addressed in scientific literature. Overall, when it comes to the study of materials with a wide range of elastic moduli, the functions that best represent this relationship are non-linear and do not depend on a single parameter. In this study, the relationships between the static and dynamic elastic modulus of eight different igneous, sedimentary and metamorphic rock types, all of which are widely used as construction material, were studied. To this end, the elastic modulus values of 33 samples were obtained which, together with the values obtained for 24 other samples in a previous study, allowed a new relationship between these parameters to be proposed. Firstly, linear and nonlinear classical models were used to correlate static and dynamic moduli, giving R 2 of 0.97 and 0.99, respectively. A classical power correlation between static modulus and P-wave velocity has also been proposed, giving an R 2 of 0.99 and a sum of the squared differences (SSE) of 553.93. Finally, new equations relating static and dynamic modulus values have been proposed using new nonlinear expressions. These consider: (a) bulk density ( R 2  = 0.993 and SSE = 362.66); (b) bulk density and total porosity of rock ( R 2  = 0.994 and SSE = 332.16); and (c) bulk density, total porosity of rock and uniaxial compressive strength ( R 2  = 0.996 and SSE = 190.27). The expressions obtained can be used to calculate the static elastic modulus using non-destructive techniques, in a broad range of rock materials.