Bài viết Nghiên cứu thực nghiệm hệ số poát xông phức động của một số loại bê tông nhựa ở Việt Nam trình bày nghiên cứu thực nghiệm xác định hệ số Poát xông động của hỗn hợp bê tông nhựa bằng cách sử dụng thiết bị nén Cooper kết hợp với các đầu đo biến dạng gắn thêm có độ chính xác cao lắp đặt trên thân mẫu hình trụ tròn. | Tạp chí Khoa học Giao thông vận tải Tập 72 Số 9 12 2021 1082-1096 Transport and Communications Science Journal EXPERIMENTAL INVESTIGATION INTO THE COMPLEX POISSON S RATIO OF ASPHALT MIXTURES IN VIETNAM Bui Van Phu Nguyen Quang Tuan Nguyen Quang Phuc University of Transport and Communications No 3 Cau Giay Street Hanoi Vietnam ARTICLE INFO TYPE Research Article Received 18 09 2021 Revised 02 11 2021 Accepted 30 11 2021 Published online 15 12 2021 https Corresponding author Email buiphugt@ Abstract. Complex modulus and complex Poisson s ratio are two parameters which present the 3D linear viscoelastic properties of asphalt mixtures under cyclic loading. This paper presents experimental research to determine the complex Poisson s ratio of the asphalt mixtures using Cooper test equipment and high-precision strain gauges fixed at the surface of cylindrical specimens. The tests were performed at different temperatures and frequencies. Three types of asphalt mixture including 2 asphalt mixtures prepared with the same original 60 70 bitumen and the third one prepared with polymer modified bitumen PMB3 were used for this study. To our best knowledgement this is the first time in Vietnam the measurements of complex Poisson s ratio of asphalt mixtures are performed in a wide range of temperatures and frequencies. The test results showed that complex Poisson s ratio is not a constant factor and that depends on the frequency and temperature. The complex Poisson s ratio increases with the increase of temperature or with the decrease of frequency and vice versa. The phase angle between the axial strain and the radial strain was also determined. The test results also indicated that there is a relationship between complex Poisson s ratio and the type of tested asphalt mixtures. The shift factor values of the two asphalt mixtures used the same type of bitumen are very close. Keywords Asphalt mixtures complex Poisson s ratio linear viscoelastic
