Study on grading envelope of AC-16 asphalt mixture based on rutting resistance performance
In this paper, the coarse aggregate packing density tests are studied on different proportion the various particle sizes over 4.75mm, and the demarcation point between coarse and fine aggregate of AC-16 asphalt mixture is 4.75mm, the optimum grading of coarse aggregate is determined by the minimum voids in mineral aggregate. Freeze-Thaw Split and Rutting are tested on 9 kinds of grading AC-16 asphalt mixture with different size and proportion fine aggregate. The results show that the percent passing 4.75mm sieve has affected significantly on the high-temperature rutting resistance and water stability of the asphalt mixture. Based on laboratory test results and grading application experience, it is proposed that the engineering design grading envelope of AC-16 asphalt mixture adapted to the summer hot climates characteristics, which improved the rutting resistance capability of asphalt pavement in hot areas during summer.
Experimental Investigation of Improving Anti-stripping Performance of Asphalt Mixture
Long term immersing Marshall test and frozen-thaw cycle test were used to investigate the anti-stripping performance of andesite asphalt mixture using cement and anti-stripping agent.It can be concluded from the experimental results that both cement and anti-stripping agent show improvement on moisture stability of asphalt concrete.The anti-stripping performance is significant improved by using cement and anti-stripping agent together.
The Analysis on Fire Smoke Exhausting Robot Vibration Based on Wavelet Transform
Belt relaxation, which affects a lot on operation reliability of the fire smoke exhausting robot, is hard to detect. In this paper, a new method for belt relaxation feature recognition based on continuous wavelet transform (CWT) is proposed, and a vibration model which simplified the robot as a 2-dof forced vibration system under harmonic excitation is established. The vibration acceleration signal has been collected using the IEPE sensor and data acquisition card, experimental results verified the accuracy of the vibration model, and weak impact signal caused by the belt relaxation was distinguished, that testify the practicability of the CWT method in belt relaxation feature recognition.