Design And Study Of Multi-function Asphalt Mixture Shear Apparatus

The asphalt pavement of longitudinal bridge deck pavement, because of the load of the Vehicles, non-uniform load created huge shear force in the asphalt surface, which is the reason of the damaged bridge deck pavement. But people don't consider shear force when they design the asphalt mixture. This is the reason that extensive damage is in the bridge deck pavement. Multi-function asphalt mixture shear apparatus is design for dealing with this problem. This dissertation design and study the composition of mechanical system and data acquisition system, and develop the program of system. we produced the actual prototype, which was used in the asphalt mixture shear experiment and content the requirements of the experiment complacently. Obtained experimental parameters has important guiding significance and practical valuable of the design of asphalt mixture and prevention of the disease of asphalt concrete pavement.In the progress of study and design of the mechanical systems, this dissertation analyzed and compared lots of common modes of shear load, combined with the specific requirements of the experimental, determined the vertical load mode of asphalt mixture specimens, shear mode, the source of the shear force and the program of power transmission, which achieved horizontal shear, vertical shear, and diagonal shear mode for the shearing of asphalt mixture.In the progress of study and design of data acquisition system, we selected YZC-219 pressure sensor for picking shear force. Data acquisition card is deigned of ADUC824 single-chip and CP2101 Bridge chip, the communication between data acquisition card and host computer is through USB Serial. The procedures of single-chip are used for controlling various components of data acquisition card. After that, it sends data to host computer. Application software is developed based on VB6.0, which can realize real-time data and curves display and save them.The apparatus has an advantage of reasonable structure, compact, which is easy to achieve kinds of shear mode, continuously variable, high precision measurement, real-time and responsibility. It can achieve the shear data of asphalt mixture immediately. Through the practical application of shearing a large number of the asphalt mixture samples, it can determine the various factors on the shear properties, which can provide fundamental parameters for the design of the asphalt mixture.