格雷戈里·哈维尔（Gregory Havel）
交叉层压木材（CLT），一种制造的形式木材, was developed in Switzerland and Germany in the 1990s. Its use is common in Europe, becoming common in Canada, and may soon be common in the United States. It has been used extensively in commercial and residential buildings of five to eight stories, and its designers proposed that high-rise buildings can be constructed of it in place of steel and concrete. The size and strength of the panels make it useful in prefabricated structures, since it provides nearly the strength of concrete with less weight.
CLT panels (照片1)是由几层空间的木材(2 x 4, 2×6) stacked with adjacent layers at 90 degrees to each other. The boards are glued together on their wide faces and sometimes also on the edges. A CLT panel has at least three layers, and may have seven or more layers.
（1）
用于组装CLT面板的粘合剂通常是热固性树脂，例如今天在胶合板中使用的粘合剂，定向链板（OSB）和其他木制产品。但是，也已经使用了热塑性树脂。
For specific applications, CLT panels are manufactured in widths to 11 feet 8 inches (3 m); and in lengths to 59 feet (18 m), depending on transportation regulations and the vehicles that are available. The individual boards running lengthwise in a CLT have finger joints (照片2）他们在一起的地方。
（2）
The boards in the outer faces of CLT wall panels are usually vertical, parallel to the loads imposed on them from above. For floor and roof panels, the boards usually run parallel to the long span and perpendicular to the beams that support them.
CLT面板的建筑物可以是平台或气球结构。The most common connectors between these panels and other structural members are construction adhesives; self-tapping wood screws; bolts; dowels; splines; metal bracket and fastener systems; dowels; and ledger boards.
尽管CLT面板可能与熟悉的I-tosist和木桁架结合在一起，但它们不是轻量级的结构组件。它们的重量与相同尺寸的锯木材大致相同。
CLT panels are promoted as having excellent fire resistance, comparable to that of non-combustible materials and to heavy timber (Type IV) construction, due to the ability of thick wood assemblies to char slowly at a predictable rate while maintaining most of their strength during the exposure. After testing CLT panels to the standard fire resistance test (CAN/ULC S101 (Canada), ASTM E119 (USA), and ISO 834 in other countries), manufacturers propose that a five-layer CLT floor panel can receive a 1.5-hour rating; and a three-layer wall panel can receive a 45-minute rating. This fire resistance is based upon the insulating properties of the char layer that develops during the exposure to the fire, and assumes that a thermoset resin adhesive has been used, rather than a thermoplastic resin.
A 5/8-inch (15.9mm) layer of Type X gypsum board on the exposed side of the panel adds 30 minutes of fire resistance; and two layers add 60 minutes of fire resistance to the assembly.
在建筑构建中使用CLT面板需要对建筑物代码进行重大更改，尽管随着基于绩效的代码的过渡，它们可能已经在住宅和轻型商业建筑中使用了。
交叉层压的木材没有足够长的历史，无法为消防员提供有关其在火灾，地震和飓风等异常情况下的行为的信息。我们需要观察我们的响应区域的施工，并在看到使用这些材料时注意到我们的事前计划。我们还需要在异常情况下共享有关使用CLT的结构行为的信息，以减少由于意外的结构崩溃而导致的消防员死亡和伤害的可能性。
有关交叉层压木材制造和使用的详细信息，请搜索互联网“交叉层压木材”。
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格雷戈里·哈维尔（Gregory Havel）一世S是伯灵顿镇（WI）的成员消防部门;退休的副局长和培训人员;以及30年的老兵消防。He is a Wisconsin-certified消防教练II，消防官II和消防检查员；兼职在structor在消防网关的程序技术的College; and安全director for Scherrer Construction Co., Inc. Havel has a bachelor’s degree from St. Norbert College; has more than 30 years of experience in facilities management and building construction; and has presented classes at FDIC.
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