A sandwich wall-panel solution based on Cross-Laminated Timber (CLT) has been recently developed aiming to rationalize the wood volume and combine it with a low-density core layer for improved thermal insulation and reduced weight. Such panel, named Cross-Insulated Timber (CIT), was previously optimized to fulfil structural and thermal requirements with a minimum production cost. The layout of the new panel is similar to the one of a five-layer CLT panel, but the inner layer is made of polyurethane rigid foam instead of timber. Besides its technical and economical benefit, it is also of interest to assess its environmental impact. This paper presents a study about the environmental impact assessment through Life-Cycle Analysis (LCA) of this new type of wood-based sandwich wall panel. A cradle-to-gate LCA with consideration of different end-of-life scenarios is performed in order to identify the processes that contribute the most to the environmental impact of the CIT panel solution proposed during its life cycle, namely during manufacturing. The LCA includes also the comparative assessment of: (i) varying the thickness of the wood layers, with respect to the optimized CIT panel; (ii) using an alternative core material, namely insulation cork board (ICB), and (iii) applying structurally equivalent three-layered CLT solutions, with alternative core materials. The results obtained show that the manufacturing process of the CIT panel, namely the polyurethane foam production and the press and curing processes during the panels assembly are the ones that produce the highest impacts. It was also found out that varying the thickness of the wood layers compared to the optimized solution leads, in general, to an increase in all impact categories. This means that the optimized solution in terms of economic costs is also the one which presents the lowest environmental impacts. Compared to equivalent CIT panels with ICB core and CLT solutions, the environmental performance of the panel proposed was better for some impact categories, while it was worse in others.

最近开发了一种基于交叉层压木材（CLT）的夹心墙板解决方案，旨在合理化木材体积并将其与低密度芯层结合使用，以提高隔热性并减轻重量。这种面板被称为交叉绝缘木材（CIT），之前经过了优化，可以以最低的生产成本满足结构和散热要求。新面板的布局与五层CLT面板的布局相似，但内层由聚氨酯硬质泡沫材料代替木材制成。除了其技术和经济利益外，评估其环境影响也很重要。本文介绍了通过生命周期分析（LCA）对这种新型的木质夹心墙板进行环境影响评估的研究。为了确定在建议的CIT面板解决方案在其生命周期内（即在制造过程中）对环境的影响最大的过程，执行了考虑了不同寿命终结方案的从摇篮到大门的LCA。LCA还包括以下方面的比较评估：（i）相对于优化的CIT面板改变木材层的厚度；（ii）使用替代芯材，即绝缘软木板（ICB），以及（iii）使用替代芯材应用结构等效的三层CLT解决方案。获得的结果表明，CIT面板的制造过程（即聚氨酯泡沫的生产以及面板组装过程中的压制和固化过程）产生的影响最大。还发现，与优化解决方案相比，改变木材层的厚度通常会导致所有冲击类别的​​增加。这意味着就经济成本而言，优化的解决方案也是对环境影响最小的解决方案。与具有ICB核心和CLT解决方案的等效CIT面板相比，建议的面板在某些影响类别中的环境绩效更好，而在其他影响类别中则更差。