Dimensional Behavior of Nail-Laminated Timber-Concrete Composite Caused by Changes in Ambient Air, and Correlation among Temperature, Relative Humidity, and Strain
Sung-Wook Hwang,
Hyunwoo Chung,
Taekyeong Lee,
Kyung-Sun Ahn,
Sung-Jun Pang,
Ji Yong Kim,
Junsik Bang,
Minjung Jung,
Jung-Kwon Oh,
Hyo Won Kwak,
Hwanmyeong Yeo
Affiliations
Sung-Wook Hwang
Research Institute of Agriculture and Life Sciences, Seoul National University
Hyunwoo Chung
Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University
Taekyeong Lee
Research Institute of Agriculture and Life Sciences, Seoul National University
Kyung-Sun Ahn
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
Sung-Jun Pang
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
Ji Yong Kim
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
Junsik Bang
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
Minjung Jung
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
Jung-Kwon Oh
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
Hyo Won Kwak
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
Hwanmyeong Yeo
Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University
A timber-concrete composite (TCC) slab composed of nail-laminated timber (NLT) and topping concrete (TC) was developed for flooring applications. The NLT was laminated alternately with lumber and plywood. To investigate the dimensional behavior of the TCC slab, the temperature, relative humidity (RH), and dimensional changes of the slab exposed to outdoor air were monitored for 205 days. Temperature change was directly transmitted to both components, and RH change was gradually transmitted to the NLT. Concrete pouring caused a sharp increase in NLT width, which was the laminating direction of the nails. This resulted from swelling of the wood because of the moisture in the concrete mixture and loosening of the nail lamination. The member composition for the nail-laminating system, fastener type, and concrete volume help to secure the dimensional stability of the NLT. Cracks in the TC caused width deformation, which was recovered by drying shrinkage of the TC. Correlation analysis among temperature, RH, and strain indicated that dimensional changes in NLT correlated strongly with RH, while those in TC correlated strongly with temperature. The correlation between longitudinal strain in the TC and strain in the three directions of the NLT was attributed to the notches designed for mechanical connection.
