Sponsored by Zhangye Chengtou Group, Changan University Continuing Education College, National Engineering Laboratory for Highway Maintenance Equipment and Changan University Magazine, Zhangye Rongchang Municipal and Nanyang Yalong Road Machinery Manufacturing Co., Ltd. The Technical Seminar (Communication) was held on November 18, 2017 in Zhangye, Gansu.

Dr. Xu Jian, Road Engineering Expert and Researcher, Highway Science Research Institute, Ministry of Transport, Zhang Xiongong, Secretary General of China Construction Machinery Industry Association Road Construction Machinery Branch, Professor Hao Peiwen, Professor Liu Honghai of Chang'an University, Xie Liyang, Deputy Director of Xi'an Road Construction Machinery Testing Center, and other experts Nearly 100 representatives from the road construction and maintenance industry in the province and surrounding areas gathered in Guganzhou, focusing on the theme of “Green Mountain and Green Mountain is Jinshan Yinshan, insisting on the harmonious coexistence of human and nature”, and explore how to use technology such as regeneration and warm mixing to achieve high efficiency. Environmentally-friendly production and recycling of road materials.

Dr. Xu Jian from the Highway Science Research Institute of the Ministry of Transport pointed out that in China, only the large and medium-sized repair projects of the trunk roads generate 160 million tons of asphalt pavement materials every year, and the recycling rate is less than 30%. The national trunk highway only accounts for 11.2% of the total road mileage of the country. According to this calculation, the entire road network in China generates about 1 billion tons of waste pavement materials every year; the wall with a section size of 1 m2 can circle the earth's equator 10 times. How to dispose of thousands of tons of waste asphalt mixture is also a problem that plagues the construction contractor of the road reconstruction project.

Recycling old materials can turn waste into treasure, which is both economical and environmentally friendly. Adding old materials to the plant's hot-mixing equipment will increase the profit per ton of asphalt mixture, but the added ratio cannot be set as desired. It will be affected by factors such as the ageing of the asphalt of the old material, the water content, the mixing temperature, and of course the equipment. How to increase the ratio of RAP incorporation? How to ensure the performance of recycled mix? What kind of asphalt mixing equipment can be called environmental protection? These are all important topics in this seminar.

Professor Hao Peiwen from Chang'an University introduced the RAP recycling technology and experience in the United States, Europe and Japan, and warned that it is a wrong idea to focus on the recycling of RAP on the surface layer. RAP should be applied at different levels to regenerate according to traffic volume. .

He suggested increasing the RAP content by lowering the mixing temperature. At the same time, he also reminded delegates that the low temperature cracking, fatigue cracking and water damage of the mixture after RAP increase must be considered. For aging severe RAP, consider adding anti-stripping agent. To improve the TSR (freeze-thaw splitting tensile strength ratio).

Professor Liu Honghai put forward several key issues and their own opinions on the plant heat regeneration technology - how to control the grading? How to avoid further aging of asphalt? How to ensure that the aged asphalt is fully regenerated? How to determine the proportion of RAP added? How is the mixing time allocated? How to solve the problem of wall material sticking? How to reduce the pollution of the dust bag?

In recent years, asphalt mixing equipment manufacturers have launched a variety of environmentally friendly asphalt mixing plants. Which of these distinctive asphalt mixing plants can really be considered environmentally friendly? Xie Liyang, deputy director of Xi'an Road Construction Machinery Testing Center, believes that the so-called environmentally friendly asphalt mixing plant should meet at least the following requirements: in the production process, the particulate matter, asphalt smoke, sulfur dioxide, nitrogen oxides, carbon monoxide and noise generated by the mixing equipment Effective control, emission indicators meet the requirements of relevant national standards; odor, wastewater, waste liquid, waste materials are properly disposed of; visual perception should be pleasant.

Shen Yuanlin, the chief engineer of Yalong Construction Machinery, introduced the company's integrated asphalt mixture temperature mixing equipment. He said that this product adopts the original, regenerative and warm mix design, which can be used in one machine. The mixing pot is located under the regeneration building and is fully integrated with the regenerative drum. The vertical addition of the recycled material not only reduces the wear, but also solves the problem of the regreasing material adhering to the chute, so that a high proportion of regeneration can be achieved.

Gansu is a Shaolin province with a forest coverage rate of only 11.28%. Zhangye City is located in the middle of the Hexi Corridor, the northern part of the Qilian Mountains, and the second largest inland river in China, the Heihe River runs through the whole territory, and it is important to protect the green mountains and green waters. Shi Yan, deputy director of the Municipal Public Utilities Administration of Zhangye City, said: "Qilian Mountain and Heihe River are the green mountains and green waters of Zhangye. Protecting them is the 'Jinshan Yinshan' that protects our Zhangye people." On the afternoon of the 18th, the delegates visited Zhang Wei. Chengtou Group's integrated asphalt mixture temperature mixing equipment. “We chose Yalong’s environmentally friendly asphalt mixing equipment based on this concept,” he said.