This paper presents an experimental study about the acoustic and thermal behaviour of a novel type of sandwich panel solution based on Cross-Laminated Timber (CLT). The layout of the new panel, named Cross-Insulated Timber (CIT), is similar to the one of a five-layer (CLT) panel, but the inner layer is made of polyurethane (PUR) rigid foam instead of timber, aiming to rationalize the wood volume and combine it with a low-density core layer for improved thermal insulation and reduced weight. For the acoustic behaviour, the study included the assessment of (i) the airborne and impact sound insulations of the developed panel, as well as of equivalent-thickness CLT solutions, and of (ii) the suitability of analytical models to describe such sound insulation. In general, the airborne and impact sound insulation of the CIT panels were found to be lower than that of CLT panels with equivalent thickness, namely due to their mass differences. Analytical models available in the literature to describe the airborne sound insulation of typical sandwich panels failed to describe the behaviour of the CIT panels. The Sharp model for homogeneous isotropic elements was able to provide a good description of the airborne sound insulation behaviour of the thicker CIT panels; however, it also failed to describe the behaviour of the thinner CIT panels. An adaptation of such model, by replacing the typical critical frequency due to bending by the dilatational frequency, enhanced the accuracy of predictions. An empirical model to estimate the impact sound insulation of both CIT and CLT panels was also proposed and fitted quite well the results. Regarding the thermal behaviour, some variability was found in the thermal resistance of the CLT and CIT panels, which was attributed to the intrinsic scatter in their material properties, namely for wood. Despite such variability on the coefficient of thermal conductivity of wood, its overall influence on the thermal resistance of the CIT panel solutions was actually marginal due to the considerably lower thermal conductivity of PUR. As expected, the analytical model (conventional heat conduction) was able to predict the thermal resistance of the CIT panels, with good accuracy.

本文介绍了一种基于交叉层压木材 (CLT) 的新型夹芯板解决方案的声学和热学行为的实验研究。新面板的布局称为交叉绝缘木材 (CIT)，类似于五层 (CLT) 面板之一，但内层由聚氨酯 (PUR) 硬质泡沫制成，而不是木材，旨在合理化木材体积并将其与低密度芯层相结合，以提高隔热效果并减轻重量。对于声学行为，该研究包括评估 (i) 所开发面板的空气传播和撞击隔音，以及等效厚度的 CLT 解决方案，以及 (ii) 描述此类隔音的分析模型的适用性. 一般来说，发现 CIT 面板的空气传播和撞击隔音效果低于具有相同厚度的 CLT 面板，即由于它们的质量差异。文献中描述典型夹芯板空气声隔离的分析模型未能描述 CIT 板的行为。均质各向同性单元的 Sharp 模型能够很好地描述较厚 CIT 板的空气声隔离行为；然而，它也未能描述更薄的 CIT 面板的行为。这种模型的适应，通过用膨胀频率代替由于弯曲而引起的典型临界频率，提高了预测的准确性。还提出了一个经验模型来估计 CIT 和 CLT 板的冲击隔音效果，并且与结果拟合得很好。关于热行为，在 CLT 和 CIT 面板的热阻中发现了一些变化，这归因于它们的材料特性的内在分散，即木材。尽管木材的导热系数存在如此大的差异，但由于 PUR 的导热系数相当低，因此它对 CIT 面板解决方案的热阻的总体影响实际上是微不足道的。正如预期的那样，分析模型（传统热传导）能够准确地预测 CIT 面板的热阻。这归因于其材料特性的内在散射，即木材。尽管木材的导热系数存在如此大的差异，但由于 PUR 的导热系数相当低，因此它对 CIT 面板解决方案的热阻的总体影响实际上是微不足道的。正如预期的那样，分析模型（传统热传导）能够准确地预测 CIT 面板的热阻。这归因于其材料特性的内在散射，即木材。尽管木材的导热系数存在如此大的差异，但由于 PUR 的导热系数相当低，因此它对 CIT 面板解决方案的热阻的总体影响实际上是微不足道的。正如预期的那样，分析模型（传统热传导）能够准确地预测 CIT 面板的热阻。