The Office of Graduate Administration is pleased to announce that Hamidreza Chaboki will be defending their thesis as a candidate for the degree Master of Applied Science in Engineering.

You are encouraged to attend the defence. The details of the defence and how to attend are included below:

DATE: 27 March, 2024

TIME: 10:00 AM (PT)

DEFENCE MODE: Remotely via Zoom

Virtual Attendance: Please contact the Office of Graduate Administration for information regarding remote/online attendance. 

To ensure the defence proceeds with no interruptions, please mute your audio and video on entry and do not inadvertently share your screen. The meeting will be locked to entry 5 minutes after it begins: ensure you are on time.

THESIS ENTITLED: A CONNECTION FOR TWO-WAY SPANNING CROSS-LAMINATED TIMBER CONCRETE COMPOSITE FLOORS

ABSTRACT: Cross-laminated timber (CLT)-concrete composite (CLTCC) floors have gained popularity in recent years due to their advantages over pure wood panels. They offer a high load-carrying capacity, increased stiffness, improved fire resistance, vibration performance, sound insulation, and thermal mass, making them suitable for a wide range of applications, including two-way spans. However, to fully utilize the two-way span capability of CLTCC floors, the minor strength axis panel-to-panel edge connections need to withstand out-of-plane bending for composite action.

In this study, experimental and numerical analyses were conducted to investigate the use of steel kerf plates (K connection) and steel T-bars (T connection) as edge moment and shear connectors in CLTCC floors. The kerf plates were embedded in five-layer 139 mm thick CLT panels to a depth of 35 mm, and T-bars were mounted with self-tapping screws to connect two CLT panels of 600 mm length from the top and LVL spline from the bottom. T-bars were connected to CLT by screws in the shear zone as shear connectors.

A total of 30 test specimens were subjected to shear and bending loading to evaluate load carrying capacity, rotational and bending stiffness. In the shear tests, the T connection exhibited a stiffness approximately twice that of the K connection in the minor direction, with a 46% greater load-carrying capacity. The T connection in both directions could provide the two-way composite action required in the CLTCC slab. However, the T connection serviceability stiffness in the minor direction was approximately 40% lower than that in the major direction. The bending tests demonstrated that the combination of T connection and LVL spline effectively reached the rotational and bending stiffness, as well as the load-carrying capacity, of a continuous CLT panel with the same layup. While T and K connections achieved similar load-carrying capacity, the bending stiffness of the K connection was only half of the T connection. In addition, the rotational stiffness with the T connection was approximately 1.6 times greater than that of the K connection. The composite efficiency was 53% for the T connection and 7% for the K connection, demonstrated that only the T connection provides composite behavior in the minor strength axis.

In the numerical investigation, a sensitivity analysis was executed to assess the factors impacting the bending capacity and deformations of CLT and CLTCC slabs interconnected by T connections. Subsequently, a 9 x 12 m CLTCC slab with T connections was simulated. The twoway action was predominantly influenced by the minor axis, and the proposed connection demonstrated adequate stiffness in facilitating the transfer of moment and shear forces between panels and layers.

COMMITTEE MEMBERSHIP:

Chair: Dr. Fan Jiang, University of Northern British Columbia

Examining Committee Members:

Supervisor: Dr. Jianhui Zhou, University of Northern British Columbia

Co-Supervisor: Dr. Thomas Tannert, University of Northern British Columbia

Committee Member: Dr. Fei Tong, University of Northern British Columbia

External Examiner: Dr. Md Shahnewaz, Fast + Epp