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Determination of criteria for the acceptance of shotcrete for certification
Published in Erik Stefan Bernard, Shotcrete: More Engineering Developments, 2004
M. Jolin, F. Gagnon, D. Beaupre
Results related to the second objective have already been presented (Beaupré & Jolin 2001). This previous project confirmed and characterised what several knew intuitively: the nozzleman’s experience combined with fresh shotcrete consistency are the key parameters affecting the quality of encasement around the reinforcement. It was shown that good quality encasement is obtained not only through good nozzleman skills, but also through good mix design that will lead to good placement properties. Furthermore, this earlier project facilitated the identification of different types of defects (voids or sand pocket) which could be related to specific parameters such as lack of experience or improper shooting consistency.
The Use of Expanding Monomers in Embedding and Related Processes
Published in Rajender K. Sadhir, Russell M. Luck, Expanding Monomers, 2020
The terms embedding, potting, casting, encapsulation, and impregnation are widely and often interchangeably used in the synthetic resin application industry. All these processes imply the use of resins at or near ambient pressure. This distinguishes such processes from molding, which is an embedment technique in which an object is encased in resin which flows into the mold under high pressure. It is, therefore, appropriate to more stringently define the above terms and, in so doing, we will follow the system used in the Encyclopedia of Polymer Science & Technology.1Casting is the complete encasement of a part, component, device, or assembly in a resin to some uniform external shape achieved with the use of a mold which is removed after the process is completed (i.e., after the resin is cured).Potting is a similar process to casting, except that the part to be potted is positioned within an integral container which becomes the outer surface of the completed potting.Impregnation is a process where a liquid resin is forced into the interstices of the part, component, device, or assembly, after which the resin is cured. This is accomplished by submerging the part in the resin and applying an internal vacuum, external pressure, or a sequence of both vacuum and pressure. Impregnation is sometimes achieved by centrifugal casting, where the part is positioned in a mold, the mold filled with resin, and the entire assembly spun at high speed, thereby causing impregnation to occur by centrifugal force.
The engineering environment
Published in Mike Tooley, Engineering A Level, 2006
Radioactive waste from nuclear power stations or other engineering activities which use radioactive materials poses particular problems. Not only is it extremely dangerous to people—a powerful cause of cancer—its effects do not degrade rapidly with time and remain dangerous for scores of years. Present methods of disposing of radioactive waste, often very contentious however, include their encasement in lead and burial underground or at sea.
Investigation on flexural behavior of a new-type composite column with steel angles
Published in Journal of Asian Architecture and Building Engineering, 2020
Jie Ding, Yun Zou, Cheng-Quan Wang, Hang-Fei Zhou, Tian-Qi Li
In recent years, the steel reinforced concrete (SRC) columns have been widely used for high-rise buildings and large-span structures because of their advantages in bearing and seismic performance (Ellobody and Young 2011; Soliman, Arafa, and Elrakib 2013; Chen, Chen, and Hoang 2016; Zhu, Jia, and Gao et al. 2016; Lai, Richard Liew, and Wang 2019; Yue, Qian, and Beskos 2019; Shichun, Xiongjun, and Zhanqin 1996; Zixiong, Zhiwei, and Yang). For conventional SRC columns Figure 1(a), the steel section was placed at the center of cross section and the reinforcement cage was placed at the edges of cross section, which effectively improved overall shear resistance. In order to make full use of the bending resistance of steel section, extensive researches have been conducted and SRC columns with different forms have been proposed based on experimental studies, numerical simulations, and theoretical predictions (Feng et al. 2015; Zhou and Liu 2010; Zhou, Yan, and Liu 2015; Qi et al. 2011; Liu et al. 2019; Yang et al. 2018; Ding et al. 2017; Zhu et al. 2010; Chang, Wei, and Yun 2012; Chang et al. 2013; Yan, Zhou, and Liu 2019; Wang, Liu, and Zhou 2016). This study develops a new type of precast L-shape steels and infilled reinforced concrete (LSRC) composite column Figure 1(d), where the flexural resistance of L-shape steel placed at corners of the cross section is significantly larger than that of the steel section placed at the center of the cross section. The four L-shape steels are connected by batten plates to form a whole structure, in the meanwhile providing the shear resistance and lateral confinement. The concrete encasement effectively inhibits the corrosion of steel and improves the fire resistance. Furthermore, the concrete encasement also prevents both local and overall buckling of the L-shape steel. The reinforced cage made up of longitudinal bars, hoops, and two-way ties is embedded in the cover, and it is used to prevent the cover concrete spalling and strengthen the cooperative deformation capacity between the steel and concrete.