Developing sustainably constructed buildings is an urgent concern as cities look to decrease their ecological footprint. Skidmore, Owings &Merrill LLP (SOM) sought to address this issue by exploring the potential of mass timber to reduce the embodied carbon footprint of high-rise buildings. The Timber Tower Research Project, funded by the Softwood Lumber Board (SLB) and launched in 2013, examined solutions that could utilize mass timber as the main structural material to reduce the embodied carbon footprint of buildings by 60 to 75 percent compared to a benchmark concrete building. The research team proposed a structural system called the Concrete Jointed Timber Frame, a system which employs mass timber for main structural elements and reinforced concrete for connections. This approach was further developed in a second report in 2014 that focused on gravity framing systems and recommended a physical testing program.
隨著城市希望擴大生態足跡，設計以可持續性方式建造的建築也就成為需迫切考慮的問題。SOM希冀發掘層壓實木減少高層建築隱含碳足跡的潛力，從中尋求解決方案。木造塔樓研究項目由軟木材組織（SLB）出資，於2013年啟動，檢驗了用層壓實木作為主要結構材料的做法，驗證了可使建築隱含碳足跡比基準混凝土建築減少60%到75%。研究團隊提出一種稱為「混凝土節點木框架」的結構系統，該系統使用層壓實木建造主要結構元素，用鋼筋混凝土製作接縫節點。這個方法在2014年的第二次報告中得到進一步深化，報告重點研究了承重框架系統，並推薦了一套物理測試程序。
To advance the findings of the research initiative, SOM and Oregon State University (OSU), with support from the Softwood Lumber Board, developed a comprehensive physical testing program that, to date, has included nearly 20 tests of varying sizes and configurations. On August 8th, the successful test of the final full-scale specimen provided strong evidence that the timber-concrete composite system can satisfy code requirements and compete with traditional construction methods.
為了推進研究結果，SOM與俄勒岡州立大學（OSU）在軟木材組織的支持下，研發了一套綜合物理測試程序，至今已包括近20項各種尺寸和構造的試驗。最終的全比例樣板於8月8日成功通過測試，有力地證明了木材-混凝土組合系統可滿足規範要求並可匹敵傳統建造方式。
The tested floor specimen—36 feet long by 8 feet wide—was modeled on a portion of a typical structural bay. The tested element was a Cross-LaminatedTimber (CLT) deck topped with a thin layer of reinforced concrete to enhance the structural, acoustic, and fire performance of the system. The two materials were joined and made composite with connectors specifically designed for this application. The reinforced concrete topping slab was thickened at the supporting CLT beam to form a rigid connection between CLT decks, a feature which allows floors to span between beams with a relatively thin cross-section. For the test, the specimen was loaded with a hydraulic actuator and was recorded by 48 different sensors over the course of two hours.
地板測試樣本長36英尺（11米），寬8英尺（2米），是按典型結構開間的一部分製作的樣板。所測試的元素是交錯層壓木材（CLT）樓承板，上面鋪薄薄一層鋼筋混凝土，以加強系統的結構、隔音、防火性能。兩種材料用為此應用特別設計的連接件連接，形成組合樓板。鋼筋混凝土面層樓板在起支撐作用的CLT梁的位置加厚，在CLT樓承板之間形成剛接，讓地板跨於梁之間的橫截面可以相對較薄。測試時，樣板上安裝了液壓執行器，在整個過程的兩小時內用48個不同感應器記錄測試。
The floor system provided greater stiffness than required by code and supported an ultimate load of 82,000 pounds—approximately eight times the required design load. The initial results are promising and will serve as the basis for verification testing—a series of tests that will address issues such as fire resistance—which will be required before the system can be used in high-rise buildings.
地板系統的剛度大於規範要求，最終支撐了82,000磅（37,000公斤）的荷載——約為所要求的設計荷載的八倍。最初結果很有希望，將成為驗證測試的基礎。驗證測試是一系列針對防火等問題的測試，系統須通過驗證測試才能用於高層建築。
SOM Associate Benton Johnson remarked that the successful test「highlights the real benefits of the composite timber approach. We took a small amount of concrete that was necessary for acoustic and fire performance and used it to enhance the structural performance of the floor. This move allows mass timber to reach its full potential, allowing it to compete in the market while also reducing the carbon footprint of cities.」
SOM的理事BentonJohnson表示這次測試成功「彰顯了組合木材方法的真正優勢。為隔音和防火性能必須使用混凝土，我們用這少量的混凝土加強了地板的結構性能。這個做法讓層壓實木充分發揮潛力，在市場上具有競爭力，同時減少城市的碳足跡」。