دانلود رایگان مقاله انگلیسی ویژگی های دمپینگ ملات امولسیون آسفالت سیمان - الزویر 2018

abstract

Cement asphalt emulsion mortars are widely used as construction and building materials, such as high speed railways and road pavements. Their damping characteristics are very important to resist vibration and the deformation caused by repeating loads. Therefore, it is of greatly theoretical and practical significance to study the damping performance of the mortars. In this work, dynamic mechanical analysis (DMA) test was innovatively conducted to analyze damping parameters of the mortars, such as loss factor and complex modulus. The environment scanning electron microscope (ESEM) was adopted to characterize the microstructures of the mortars. The mechanical properties of the mortar were characterized by the compressive strength and flexural strength test. The results show that the addition of asphalt emulsion decreases the mechanical properties of the mortar, but the plasticity of the mortar is improved. The higher the asphalt emulsion content is, the higher the loss factor of the mortar is; and the ability of the mortar to resist deformation is stronger. With the increase of temperature, the loss modulus of the mortar decreases, but the loss factor increases. The damping performance of the mortars can be enhanced. The damping performance of cement asphalt emulsion mortar at low loading frequency is higher than that of the mortar at high loading frequency. With the increase of a/c ratios, asphalt attached to surface of cement hydrates increases. The cement asphalt emulsion mortars with suitable asphalt-cement (a/c) ratios possess excellent damping performance.

4. Conclusions and summary

This experimental study has focused on the effects of a/c ratios in enhancing the damping properties of the cement asphalt emulsion mortars. On the basis of the experimental tests and the theoretical analyses, the following conclusions can be drawn:

1) With the increase of a/c ratios, compressive strength and flexural strength of cement asphalt emulsion mortars decrease. However, the higher a/c ratio can improve the ability to resist the deformation and enhance the plasticity of the mortars. Asphalt attached to surface of cement hydrated products increases significantly with the increase of a/c ratio, which directly influences mechanical properties of the mortars.

2) The addition of asphalt emulsion can significantly improve the damping performance of the cement asphalt emulsion mortar. For, the cement asphalt emulsion mortars with 0.17 a/c ratio, the rigidity of the mortar is dominant and the viscoelasticity of the mortar is very poor. The higher the asphalt emulsion content is, the greater the loss factor of the cement asphalt emulsion mortar is. The energy dissipation capacity of the mortar can be stronger.

3) The damping performance of cement asphalt emulsion mortars is influenced by the loading frequency. The loss factor of cement asphalt emulsion mortar exists a higher increase at low loading frequencies and a lower increase at high loading frequencies.