The effects of connection types and nailing angles on the shear resistance performance of
cross-laminated timber (CLT) connections using self-tapping screws were investigated in the study.
The 5-layer- and 5-ply-CLT connections with heterogeneous-grade construction were made using
Cryptomeria japonica plantation timber, and were also mixed with southern pine (Pinus spp.).
Results showed that the maximum shear capacity, yield shear load, and initial stiffness of a CLT
surface spline connection were 16, 13, and 22%, respectively, of a CLT butt connection. The maximum
shear capacity, yield shear load, and initial stiffness of a CLT half-lap connection were 63,
64, and 38%, respectively, of a CLT butt connection. As to effects of nailing approaches, the maximum
shear capacity of connections fastened with self-tapping screws at angles of either 90° or 45°
were 40% of that with double angles of a 30°~45° approach. The yield shear loads obtained from
both 90° and 45° nailing approaches were 30 and 47%, respectively, of that with double angles of
the 30°~45° approach. Values of initial stiffness were 11 and 35%, respectively, of that with double
angles of the 30°~45° approach. Improvement in the shear resistance was found in a butt connection
fastened with self-tapping screws when southern pine laminae were used for outer layers of
the CLT. CLT connections fastened with self-tapping screws were classified based on the obtained
ductility. The connection assembled with a surface spline was classified into the high-ductility category,
the CLT butt connection was in the moderate-ductility category, and the CLT half-lap connection
was in the low-ductility category.