• Korean Journal of Construction Engineering and Management
• /
• v.22 no.3
• /
• pp.31-39
• /
• 2021

The modular construction method is an off-site construction method using built-in structures from the manufacturing facilities. Modular construction is commonly applied to buildings which have relatively smaller and simpler structures than other types of buildings. Although modular building has emerged in the domestic construction industry as an alternative building strategy, previous researches on the environmental characteristics of modular building has not been comprehensively studied. Thus, this study empirically analyzed the insulation performance of thermal bridge and condensation parts of the modular buildings by using IR image analysis, Air-Surface Temperature Ratio method, and temperature difference ratio. The insulation performance analysis was conducted by comparing a modular building and a RC building in Seoul. The results shows that there was no significant difference between insulation performances of RC building and modular building. Furthermore

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.26 no.3
• /
• pp.209-222
• /
• 2024

The Earth Pressure Balance (EPB) shield Tunnel Boring Machine (TBM) is widely used for underground tunnel construction for its advantages, such as eliminating the need for additional facilities compared to the slurry shield TBM, which requires Slurry Treatment Plant (STP). During EPB shield TBM excavation, a soil conditioning technique is employed to enhance the physical properties of the excavated soil by injecting additives, thus broadening the range of applicable ground conditions to EPB shield TBMs. This study explored the use of xanthan gum, a type of biopolymer, as an alternative to the commonly used polymer additive. Biopolymers, derived from biological sources, are fully biodegradable. In contrast to traditional polymers such as polyacrylic acid, which contain environmentally harmful components, xanthan gum is gaining attention as an eco-friendly material due to its minimal toxicity and environmental impact. Test conditions with similar workability were established through slump tests, and the rheological characteristics were assessed using a laboratory pressurized vane shear test apparatus. The experiments demonstrated that, despite exhibiting similar workability, the peak strength in the flow curve decreased with increasing the content of xanthan gum. Consequently, a correlation between the xanthan gum content and peak strength was established. Replacing the traditional polymers with xanthan gum could enable stable EPB shield TBM operation by reducing equipment load, in addition to offering environmental benefits.