Seismic Safety Research Center, Korea Institute of Civil Engineering and Building Technology, 283 Goyangdae-ro, Ilsanseo-gu, Goyang-si, Gyeonggi-do 10223, Korea.
Department of Civil Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Korea.
Sensors (Basel). 2019 Nov 19;19(22):5053. doi: 10.3390/s19225053.
Slip-forming in concrete construction enables the continuous placement of concrete using a climbing form, the efficiency of which depends on appropriate slip-up timing. This implies the importance of knowing accurately the development of concrete strength over time, which has been assessed manually to date in construction fields. This paper presents a method for automating the slip-forming process by determining the optimal slip-up time using the in-situ strength of concrete. The strength of concrete is evaluated by a formula relating the strength to the surface wave velocity measured with ultrasonic sensors. Specifically, this study validates the applicability of the slip-form system with ultrasonic sensors for continuously monitoring the hardening of concrete through its application in several construction sites. To this end, a slip-form system with a pair of ultrasonic modules at the bottom of the panel was tested and the time variation of surface wave velocity in the concrete material was monitored during the slip-forming process. The results show that the proposed method can provide the optimal slip-up time of the form to automate the slip-forming process. This approach is expected to apply to other construction technologies that required the continuous monitoring of concrete strength for construction efficiency as well as quality maintenance.
滑模施工通过攀爬模板实现混凝土的连续浇筑，其效率取决于合适的脱模时机。这意味着准确了解混凝土随时间推移的强度发展至关重要，迄今为止，这在建筑领域一直是通过手动进行评估的。本文提出了一种通过使用混凝土的现场强度来确定最佳脱模时间从而实现滑模施工自动化的方法。通过将强度与超声传感器测量的表面波速度相关联的公式来评估混凝土的强度。具体来说，本研究通过将其应用于几个建筑工地，验证了带有超声传感器的滑模系统在通过连续监测混凝土硬化情况方面的适用性。为此，测试了带有一对超声模块的滑模系统，并在滑模施工过程中监测了混凝土材料中表面波速度的时间变化。结果表明，所提出的方法可以为自动化滑模施工提供最佳的脱模时间。该方法有望应用于其他施工技术，这些技术需要对混凝土强度进行连续监测，以提高施工效率和保证施工质量。
