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Cross-laminated timber (CLT) is an innovative building material that has become increasingly popular in midrise building construction due to its rapid assembly capability, environmental friendliness, and beneficial strength-to-weight ratio. Currently, CLT balloon-style construction requires the engineering team to use the alternative means procedure within design standards for areas of high seismicity in the US. This study experimentally investigated the behavior of CLT balloon-style construction connections and characterized their behavior. Various wall-to-floor and panel-to-panel connections were identified in the test matrix and tested under monotonic and cyclic loads. A series of full-scale CLT shear wall tests focusing on the response of connections was conducted, adopting a biaxial loading protocol to characterize connection and system response to loading in two directions. [ABSTRACT FROM AUTHOR]

This paper presents the seismic performance of two types of cold-formed steel wall systems as characterized during a full-scale five-story building shake table test program: (1) an exterior architectural façade, which spanned the lower three levels of the building, and (2) interior partition wall systems distributed at all levels of the building. The test building was subjected to a suite of earthquake input motions of increasing intensity, first while the building was isolated at its base, and subsequently while it was fixed to the shake table platen. This paper presents the observed physical and measured responses for the two cold-formed steel wall systems and in particular associates physical damage states with measured drift demands in the building. The tests illustrate damage mechanisms for cold-formed steel wall systems when used in architectural façades and highlights areas that should be given particular consideration during seismic design. [ABSTRACT FROM AUTHOR]

Abstract: A method for the analysis of rainwater ponding on flat or nearly flat one-way and two-way roofs, published in 2007, is modified. The existing method appears accurate for roofs of continuous secondary members and profiled steel sheeting, but is far too pessimistic for roofs in which all composing parts are simply-supported. After summarizing the formerly published method, a modification is proposed in order to fit better with FEM-packages, considered in this context to be exact solutions. In essence, the stored water in the deflected secondary members and steel sheeting elements is estimated more properly. An easy way has been found how to adapt the existing spring-piston model in order to better account for the correct volume of accumulated water in the secondary members and profiled steel sheeting. An application example and discussion of the results complete the article. [Copyright &y& Elsevier]

Abstract: Ponding on flat or nearly flat roofs keeps drawing attention due to the large number of collapses over the course of years. Though at present computer programs start to offer functionality to check the sensitivity of roofs for water accumulation, true insight appears to be missing on the very nature of the phenomenon. In this paper two models are presented for regular grids, that fill the understanding gap: the piston–spring model for rather stiff roofs and the bar–spring model for extremely flexible ones. The models apply for horizontal roofs, sloped roofs, roofs with initial deflection due to permanent load, camber and composed roofs. Rain showers are considered, so heavy that the water level keeps staying at the specified height of the emergency discharge (full ponding). The case of a specified limited water volume (partial ponding) is not considered. Full ponding is studied for both fully filled roofs and partially filled roofs. The derived theory brings to light that two main roof categories exist; one stress-dominated and one stability-dominated. Four application examples demonstrate that the models are easy-to-use design tools for structural engineers. The derived theory clarifies the effect of the profiled steel roof sheeting on safety and other practical hints are included in the paper. [Copyright &y& Elsevier]

Recent historians have unquestioningly supported the hypothesis that balloon-frame construction was invented in Chicago in 1833. In Space, Time, and Architecture, Sigfried Giedion based his argument on a set of circumstances peculiar to Chicago and on the improved production of nails and dimension lumber. However, at the time, Chicago was not a unique town in the Midwest, and the amount and type of materials required for balloon framing, including nails, were not significantly different from those required for timber framing. Documentary evidence suggests that the balloon frame existed elsewhere in 1833 and as early as 1804 in the French settlements along the Mississippi River. [ABSTRACT FROM AUTHOR]