Carbon 9 (C9) resin is a major by-product of the petrochemical industry and is rich in unsaturated hydrocarbons. By copolymerization with maleic anhydride (MAH), the product MAH-C9 was used as a carbon foaming agent. Combining MAH-C9 with ammonium polyphosphate (APP), which served as an acid and a gas source, an intumescent flame-retardant system was introduced into thermoplastic polyurethane (TPU). Flammability evaluation indicated that 4.5 wt% APP and 0.5 wt% MAH-C9 helped TPU achieve the maximal limiting oxygen index value of 25.9%, passing UL-94 V-0 rating. Total smoke release was decreased from 1,884.4 m 2 /m 2 for neat TPU to 833.0 m 2 /m 2 and char formation was promoted. The mechanical loss brought by 5 wt% APP was a little recovered by 4.5 wt% APP/0.5 wt% MAH

To study on the failure model, ductility, energy dissipation capacity, structural displacement, and stiffness of the portal frame structures on the effect of earthquake force, a pseudo-static experiment with a 1/3 scaled model has been completed. Based on the test result, though the ductility and the energy consumption capacity of the structure are poor, the requirement on aseismatic bearing capacity is satisfied, because the structure suffers the smaller seismic force as the deadweight of structure is light. Built up a finite element model according to the test specimen, then performed finite element analysis, the results showed that the finite element model can be used for seismic analysis of the portal frame.

A nonlinear 3D solid model of hybrid coupled wall system with steel boundary elements has been founded by using FEM software ABAQUS to study its hysteretic behavior under cyclic loading, which considering the geometric large deformation and materials nonlinearity. To verify the efficiency of the model, two specimens with various coupling ratios of 30% and 45% are analyzed, and the results of analysis are compared with test ones. As the bearing capacities of both agree well in different loading stages, so the FEM model has enough accuracy and could be used to study the seismic behavior of hybrid coupled wall system with steel boundary elements. In addition, the results show that this new system dissipates energy by shear deformation of steel beams along and plastic hinge deformation at the bottom of wall, so it has better seismic performance.

Bamboo fibers (BF) were used as charring agent in thermoplastic polyurethane (TPU), together with ammonium polyphosphate (APP) to prepare intumescent flame retardant composites. In order to improve the dispersibility and flame retardant efficiency, BF was grafted with diammonium phosphate (DAP), named as modified bamboo fibers (M-BF). By the presence of 8 wt% APP and 2 wt% M-BF, the sample could achieve the maximal limiting oxygen index (LOI) value of 30.5% and V-0 rating in UL-94 test. The peak heat release rate for TPU/8APP/2 M-BF is 190 kW/m 2 , which is 86.0% lower than that of neat TPU. Besides, TPU/8APP/2 M-BF sample presented a tensile strength of 23.0 MPa, which was slightly lower than neat TPU sample. The thermogravimetric analysis for TPU composites and the morphology observation of the char demonstrated that APP and M-BF took effects on condensed phase through promoting the formation of intumescent char structure and free radical trapping. Meanwhile, it could release inert gases in gas phase. Therefore, M-BF exhibited great potential in applying as renewable charring agent for alleviating the depletion of petroleum resources.

To effectively control the large surrounding rock deformation of the mining roadway under multiple excavations and mining in Wangcun coal mine, the field investigation, numerical simulation, field test, and monitoring were conducted, and the characteristics of stress and deformation evolution of the surrounding rock under the influence of multiple excavations and mining were analyzed; then the collaborative supporting technology of high prestressed bolt and short anchor cables was proposed in this study. The results show the following: (1) under the influence of multiple excavations and mining, the peak vertical stress of the typical air-return roadway reaches 23 MPa, and the deformation increases by about 2.8 times after the mining of adjacent panel. (2) The principle of the roadway support under the influence of multiple excavations and mining in Wangcun coal mine is determined; from the perspective of prestress, we can conclude that the active support of short anchor cables is better than that of long anchor cables. (3) Based on the results of the field monitoring, the bolt stress can be divided into four stages: the loss stage of prestress, the sudden-decrease stage of the roof periodic weighting, the decrease stage of advanced support, and the rapid-increase stage of strong disturbance. Due to the large anchorage range of anchor cables, there is no decrease stage of advanced support. After the application of prestress, the bolt stress of side bolts and top bolts decreases, and the reduction amplitude is up to 30 kN. (4) As the panel advances, the deformation of the surrounding roadway increases, and the growth rate is also increasing gradually. However, the final displacement of the roof, floor, and two sides is within 18 mm. The bolt and anchor cables are not broken, and the control effect is good. The research results have a certain reference value for similar roadway control.