Study on pore characteristics of cement stabilized macadam

Abstract:

To study the micro pore characteristics of cement stabilized macadam and the change process of pore space structure under load, through the establishment of three-dimensional pore model to quantify the cross section pore and three-dimensional pore, and the conversion of three-dimensional pore network structure, the parameters such as pore coordination number, pore volume and throat length were extracted. The changing process of pore space structure was deduced by studying the changing rule of parameters with the step-by-step load. Results show that the quantitative porosity of cross section and three-dimensional porosity could characterize the pore change of materials. The peaks in m and n regions extended from 12.10% and 10.29% to 13.89% and 13.41%, the peak distribution region in n region spanned 11 layers. The waveforms in the m and n regions changed drastically and the micro structure of the pores changed significantly. The mean value of coordination number changed from less than 0.45 to 0.505 and the small pores in the pore volume occupied 80% of the pore space structure, but the pore volume changed with increasing load. During the gradual loading process of throat, the maximum throat length increased by nearly 2mm, the throat changed from negative to positive and the load changed the pore space structure. The change of pore microstructure and pore space structure resulted in the change of internal structure of materials and the macro failure of materials. Therefore, the macro failure of materials was essentially related to the change of pore structure.