Static and Dynamic Mechanical Properties of Cement-Asphalt Composites: Fid-Bau Portal

Static and Dynamic Mechanical Properties of Cement-Asphalt Composites

Yongliang, Liu / Xiangming, Kong / Yanrong, Zhang / Peiyu, Yan

Static and dynamic mechanical properties of cement-asphalt composites with various contents of asphalt incorporated were studied. Uniaxial compressive stress-strain curves of different cement-asphalt mortars (CAMs) with cement mass ratio (A/C) in the range of 0.2 to 1.0 were obtained by the Materials Testing System (MTS) under different testing temperatures ranging from $- 40$ to 80°C. Two typical CAMs, one with A/C of 0.2 denoted by LAC and the other with A/C of 0.9 denoted by HAC, were chosen to be tested at varied deformation rates over a range of 0.3 to 30 mm/min at room temperature. The correlation between mechanical properties, e.g., peak stress or elastic modulus, and temperature or loading rate was, respectively, acquired. As a result, temperature sensitivity and loading rate dependence for mechanical behavior of different CAMs were analyzed. Dynamic mechanical analysis (DMA) on three cement-asphalt binders (CABs) with A/Cs from 0.2 to 1.0 was carried out, and temperature spectra and frequency spectra were obtained. The Burger model was used to simulate the viscoelastic mechanical behaviors of CABs. Results indicate that peak stress and elastic modulus of CAMs decline with the increasing A/C and temperature. The temperature sensitivity and the loading rate dependence for mechanical properties of CAMs with higher A/Cs are greater than those of CAMs with lower A/Cs. To quantify the dependence of mechanical properties on temperature and loading rate, temperature-sensitive factor and rate-influencing factor are defined separately. The two factors increase with the A/C, implying that CAMs with higher A/Cs have greater dependence on temperature and loading rate. Furthermore, the two factors for peak stress are bigger than those for elastic modulus for a given CAM. Dynamic modulus of CABs descends with the increase of A/C or temperature but ascends with the loading frequency. As the temperature rises or A/C increases, the viscoelasticity becomes more remarkable. The dependence of dynamic modulus of CABs with varied A/Cs on loading frequency is successfully simulated by using the Burger model.