Grouted Bolt Connections

Double slip stiffness

Grouted bolt connections for steel-CLBT composite structures achieve more than a twofold increase in slip stiffness compared to traditional demountable bolt connections.

76735175 · Wei, Yang · Du, Hao · Zhao, Kang · Huang, Silu · Chen, Jiawei

Thin-Walled Structures 2026

Specifications

Shear capacity increase

{'zh': '45–70', 'en': '45–70'} %

Slip stiffness increase

{'zh': '1.8–10', 'en': '1.8–10'} ×

Slip stiffness ratio

{'zh': '>2', 'en': '>2'} ×

Advantages

Doubled stiffness

Compared with demountable bolted connections, the grouted bolted connections in the steel-CLBT composite system achieve more than a twofold increase in slip stiffness, enhancing composite action.

Higher capacity

The grouted bolted connections in the steel-CLBT composite system exhibit significantly higher shear capacity than those in the steel-CLT composite system (45–70% increase), with a predictable bolt shear failure mode.

Tunable stiffness

The slip stiffness can be tuned over a wide range (1.8–10 times) by varying bolt diameter, bolt strength, or grout diameter, allowing optimization for design needs.

Applications

• Steel-timber composite floors：Enhance composite action in floors, reducing deflections and improving load efficiency.
• Bamboo-timber composite structures：Exploit bamboo-timber mechanical properties with high-stiffness connections.
• Connection design：Provide design basis for high-stiffness, predictable connections.
• Engineered bamboo and timber components：Pair with engineered bamboo/timber components for efficient connections.