Experimental long-term behavior of a CLT-concrete composite floor system connected with steel plate

This paper presents the long-term experimental behavior of timber-concrete composite (TCC) floor systems with cross laminated timber (CLT) as the timber component. In TCC, the steel plates are installed between concrete and timber with adhesive. This floor system was confirmed to have high bending stiffness according to the conducted short-term bending test using the full-scale specimen. In this paper, the long-term behavior of such TCC floor was evaluated in 1270-day experiments using a full-scale specimen with a length of 6 m. The experiment was conducted in a room with uncontrolled temperature and relative humidity. As a result, it was found that the creep behavior showed a good correlation with temperature and relative humidity variations. Moreover, the amount of increase displacement during the summer tends to decrease year by year. The deflection after 1,270-day was 45.5 mm, and the creep displacement after 50 years predicted by using the power law model was 61.0 mm with a creep coefficient less than 3.60. In addition, in static bending test after long-term bending test, no performance degradation due to creep was observed.