Different methods, including bending tests and small and medium size shear tests, were used to assess the skin to stringer glue line shear strength of Radiata Pine Cross-Laminated Timber Derived Stressed-Skin Panels (CLT SSP). Bending test shear strengths were estimated using the mechanically jointed beam theory (gamma method) for CrossLaminated Timber (CLT) panels with modifications in the layers’ effective widths, and then compared with results from the small and medium size shear tests. Small and medium size shear tests proved to be possible methods for assessing bonding strength for factory production control. The small shear tests provided lower strength values and higher scatter results than those gathered from the medium size tests. The mean shear strength results obtained from bending tests were inferior to the values obtained from the small and medium size specimens. The bending tests proved necessary for assessing the mechanical behaviour of CLT SSP.
Inspection, Testing, and Monitoring of Buildings and Bridges
Depending on the severity, fire damage can compromise the structural integrity of wood structures such as buildings or residences. Fire damage of wood structures can incorporate several models that address (1) the type, cause, and spread of the fire, (2) the thermal gradients and fire-resistance ratings, and (3) the residual load capacity.
The investigator should employ engineering judgment to identify those in-service members that are to be replaced, repaired, or can remain in-service as they are. Suchjudgment will likely be based on the visual inspection of damaged members, connections, and any protective membranes.
The application of cross-laminated timber (CLT) as floor panels is limited by excessive deflection and vibration. A composite system combining CLT and ultra high-performance fibre-reinforced concrete (UHPFRC) was developed to extend span limits. Push-off tests were conducted on different connectors, and a glued-in rod connector was chosen and further refined for the proposed system. Static bending tests and free vibration tests were conducted on bare CLT panels and two composite specimens. By comparing the results, it is concluded that the proposed system considerably extend the span limits of CLT panels.
This book contains experiences and results of computer simulations in the field of research on glued laminated timber. Literature and references to the corresponding methodical approach are given to facilitate the access to the elementary basics. It also contains constructive explanations and critical annotations on modelling glued laminated timber for bending, tension and compression tests. Finally, the relevance of the simulation results for practical issues is discussed.
In this contribution bending and shear tests of cross laminated timber (CLT) plates under concentrated loads are presented. The so loaded structural members can fail either due to punching along a critical perimeter line in the vicinity of the concentrated load or in bending. Two test configurations were developed and investigated by linear elastic models. The obtained test results and observed failures as well as their correlation with the mechanical modeling are shown in this paper. The established numerical model was a 3D solid model with different material behavior for all acting stresses. The material behavior was implemented in a user subroutine for the FE program ABAQUS. By comparison of measured and computed load displacement curves numerical models could be discussed regarding their reliability and conclusions about missing input for an increasing accuracy of the model could be drawn.
The performance of timber-concrete composite bridge constructions crucially depends on the design of the joint between concrete deck and timber main girders. In research studies at the Bauhaus-University Weimar, innovative joining techniques based on grouting with highly-filled, tolerance-compensating polymer glue mortars have been developed to improve the shear capacity of this joint significantly. By applying a thin layer of polymer mortar on the top of the wooden main girder a continuous, slip-free connection to the timber can be realized. This layer can be utilized for the embedding of steel plates with welded-on shear studs (stud connectors), so that the joint to the concrete side is ensured by a standardised connection. The steel plates are rigidly anchored in the polymer mortar by adhesive bond and form closure. As an alternative, a slip-free grout-glued connection between concrete and timber can be realized by the glue mortar itself, so that also a continuous connection to the concrete is accessible, whereby manufacturing tolerances can easily be compensated due to the high degree of mineral filling of the polymer mortar. The paper focuses on experimental results of shear and bending tests for the new composite joint configurations.
Massive timber panels (MTPs) has shown a great potential in construction of tall buildings. Evaluation of the face-bond strength of MTPs is of an interest to use of this kind of products. This study was aimed at developing an appropriate test procedure for evaluating the adhesive bond strength of cross-laminated laminated strand lumber (LSL). Short span bending tests were conducted on two-layer asymmetric cross-laminated LSL specimens, which were adhesively bonded using two-component polyurethane (PUR) and polyvinyl acetate (PVAc). For comparison, block shear specimens were tested as well. It was found that the 2-layer asymmetric cross-laminated specimen assembly under the short span bending could be used to differentiate between good and poor bond quality.
Various kind of in-plane bending tests of cross laminated timber (CLT) with different shapes have been previously carried out. The results indicate that the bending strength of CLT loaded in plane reduces as the number of layer increases. To evaluate this lamination effect on in-plane bending strength of CLT, a computational model based on Monte Carlo method was developed. The estimated bending strength showed the same tendency.