Preparation And Properties Of Nanometer Montmorillonite Modified Asphalt Emulsion

While reaching a state of perfect, basic maintenance of highway has gradually become the dominant aspect in the national highway system. Asphalt emulsion is one of the most important means of highway maintenance, whose quality is required higher and higher. Meanwhile, nanometer montmorillonite (MMT) modified asphalt emulsion has a good application prospect as it has a nanoscale layered structure and the cost is low.Combining the theory with the actual situation, this paper studies the preparation of MMT modified asphalt emulsion including the raw materials and the process conditions. The composite material are characterized by using conventional test methods including penetration, softening point, ductility, rotation viscosity. And with using X-ray diffraction analysis (XRD), fluorescence microscope, atomic force microscopy, we carried on the analysis of microscopic structure. The results of the test are as follows:The emulsifying and modification are performed simultaneously, a better preparation technology of MMT modified asphalt emulsion comes when the follow process performed, We choose the emulsifier A and B as the matched emulsifier, and the mixed proportion is 2:1 in mass ratio. The soap temperature is 70℃ and the asphalt temperature is 135℃. The high-speed shear emulsifying machine shears for 2 min with a speed of 7000 r/min. The MMT modified asphalt emulsion has much better storage stability and high temperature resistant performance under the optimized preparation conditions. Emulsion particle has good dispersion that the size of the particle is normally distributed and the average particle size is nearly 1 μm. The interlayer space of MMT increased from 1.28 nm to 4.74 nm with a growth of 270%, which confirmed that the MMT had successfully intercalated into the asphalt. The hot oxygen aging simulations of MMT modified emulsified asphalt are performed by rotating thin film to heat aging test (RTFOT). And we study anti-aging mechanism through the Fourier infrared spectrometer (FTIR) and gel permeation chromatograph (GPC). Results show that when the proportion of MMT is 2%, the modified emulsified asphalt has the best anti-aging performance, the reason is that the interlayer space of MMT has reached the largest degree at this time, so the MMT highly dispersed in the asphalt, MMT can hinder the molecular weight of asphalt from getting higher and stop the trend that C=O turn into Ar-CO (aromatic ketone), Ar-CHO (aromatic aldehyde) in the process of asphalt aging. The anti-aging performance of MMT modified emulsified asphalt is far better than that of MMT modified asphalt, and similar to the performance of the OMMT modified asphalt.