Estimation of Internal Maximum Thermal Stress of Tunnel Side Wall Lining Concrete During Construction Period

Thermal cracks in lining concrete of large section hydraulic tunnel usually occur in side walls during construction, and most of them are harmful penetrating cracks. In order to meet the needs of real-time rapid control for engineering design in construction period, nine influencing factors of maximum tensile of side wall lining concrete σmax during construction period are determined on the basis of comprehensive analysis of temperature stress effects and finite element simulations, and their influencing regularities are analyzed. Then the estimation formula of σmax and real-time control method of thermal crack are put forward. Through the application of real-time temperature control and crack prevention control of lining concrete in flood discharge tunnel, the estimation formula of σmax and the real-time thermal crack control method are proved to be correct and applicable.

Preliminary Proposal for an Alternative Wall Lining Panel Based on Molded Recycled Cellulose and Designed for Home Wiring Refurbishment of Building Interior Partitions

Old dwellings usually have shortfalls in insulation, acoustic and thermal, and in security of electrical services in the interior partition walls. A common building solution is to add a wall lining with a laminate base gypsum board that improves both acoustic and thermal insulation and facilitates a new invisible cable layout without demolition. Conventional solutions have had limited success because of time consumption, environmental impact and cost. This research aimed to create an integrated building system to carry out these interior building refurbishment works quickly, cleanly and with low inconvenience and environmental impact. The research specifically focused on incorporating new molded materials that have a low environmental impact and improving the handling and future modification of thewall lining system. In response to the above goals, the product development methodology was applied to the design of an internal panel to be inserted between the existing partition wall and the closure wallboard, which is usually laminated base gypsum board (LGB). The proposed internalpanel is molded with recycled cellulose pulp (Biprocel) and has adequate relief designed to improve cable layout tasks and better join the laminate base gypsum board to the existing wall face. The development resulted from collaboration between the public administration, university researchers and undergraduate students in the co-design process. This research contributes to improving the applications of recycled cellulose fibers in molded panels for the building industry, particularly in refurbishment activities.