Papers by Author: Yue Li

Abstract: Both asphalt concrete (AC) and Portland cement concrete (PCC) are limited in applications in tunnel pavements, due to special conditions in tunnel. To improve the fire resistance, durability and comfort of the tunnel pavements material, rubber particles, lightweight aggregate and polymer were added into PCC. Experimental results showed that physico-mechanical properties such as strength, rigidity, shrinkage and abrasion resistance got worse when rubber particles and lightweight aggregate were added, but when polymer was mixed, the physico-mechanical properties were enhanced dramatically. Microstructure analysis indicated that the interface transition zone (ITZ) influenced the physico-mechanical properties of concrete directly; the ITZ bondage between rubber particles or lightweight aggregate and cement matrix was very poor, which was the main reason for the decline of physico-mechanical properties; when polymer was mixed into the concrete, the ITZ structure were improved, which made the strain energy absorbing function of rubber particles can be exerted entirely, the flexibility and the strength of ITZ were boosted, thereby the physico-mechanical properties of concrete were improved.

Abstract: The anchorage zone of pylon is the key part of the cable-stayed bridge, and it is also the difficult and important part in designing and construction of cable-stayed bridge. Especially for an abnormally shaped anchorage zone, it is hard to analyze the actual stress distribution on the bridge pylon by a simple mechanical method. The full scale segment model test of the abnormally anchorage zone of Maling River cable-stayed bridge pylon was described. In the test, the cracks, stress and deformation were observed and analyzed. Further more, the finite element analysis for the segment model was carried out. Through the contrast analysis between the model test and the finite element analysis, some important conclusions are drawn such as the model test and the finite element analysis have a good agreement, “the joints outside” and “the polyline inside” are the easy cracking zones, the cracking resistance coefficient of the model is no less than 1.3 and the destroy safety coefficient is no less than 1.6, which can provide important theoretical basis for the design and construction.

Abstract: To improve the cracking resistance of lightweight aggregate concrete, rubber particles and polymer were added. Experimental results showed that the shrinkage rate increased when rubber particles were added into lightweight aggregate concrete, but when polymer was mixed, the shrinkage rate decreased dramatically. Microstructure analysis indicated that the interface transition zone (ITZ) influenced the shrinkage performance of rubberized lightweight aggregate concrete with polymer directly; the ITZ bondage between rubber particles and cement matrix was very poor and the restriction to shrinkage was weak, which were the main reasons for the increase of shrinkage rate of rubberized lightweight aggregate concrete; when polymer was mixed into the concrete, the hole and ITZ structure of concrete were improved, which made the strain energy absorbing function of rubber particles can be exerted entirely and the flexibility of ITZ was boosted, thereby the shrinkage performance and cracking resistance of lightweight aggregate concrete were improved.