The following research presents the numerical and experimental results obtained on a reduced scale steel model of a medium-rise building structure dynamically protected with energy dissipaters. The steel-steel friction dissipates energy as the structure undergoes interstory drifts. A preliminary numerical analysis is performed to determine the best position of the friction dampers in the longitudinal frames. All the nodes of the numerical model have been assumed with the same bending stiffness. Shaking table tests have been performed, both in random vibration tests (to determine the natural periods and the dynamic characteristics of the model) and in earthquake simulation tests (to study the dynamic behaviour of the model with and without dampers). The results have been compared to those achieved during a previous experimental study based on the same model protected with only one friction damper for each longitudinal frame.

Seismic analyses of concrete structures under maximum-considered earthquakes require the use of reduced stiffness accounting for cracks and degraded materials. Structural walls, different to other flexural dominated components, are sensitive to both shear and flexural stiffness degradations. Adoption of the gross shear stiffness for walls in seismic analysis prevails particularly for the design codes in the US. Yet available experimental results indicate that this could overstate the shear stiffness by more than double, which would hamper the actual predictions of building periods and shear load distributions among columns and walls. In addition, the deformation capacity could be drastically understated if the stipulated constant ductility capacity is adopted. This paper reviews the available simplified shear and flexural models, which stem from classical mechanics, empirical formulations and/or parametric studies, suitable for structural walls at the state-of-the-art. Reviews on the recommended flexural and shear stiffnesses by prominent design codes such as ACI318-11, Eurocode 8 and CSA are included. A database comprised of walls subjected to reverse-cyclic loads is formed to evaluate the performance of each model. It is found that there exist classical models that could outweigh overconservative codified values with comparable simplicity for practical uses.

Methods to monitor the schedule and to control cost in dwelling construction projects are numerous and varied but commonly constitute an obstacle to a fast and agile response by construction managers, whose decisions require information to be comprehensive and summarized. A simple model to monitor these projects is proposed that can easily be implemented within control systems that are already in place. For the first time, process control charts are combined with cost control in dwelling construction in order to prevent overruns in terms of time and/or cost. The model facilitates the production supervision of construction contracts by regularly providing information on the work completed and the incurred cost of the production processes per period, through charting and/or summarizing this information in a manner consistent with statistical control charts. Finally, the manager can easily identify those processes which are off target by consulting control charts.

High performance concrete M60 cubes of 150 mm X 150 mm X 150 mm were tested experimentally under static loading. With the variation in the water binder ratios of 0.25, 0.28, 0.33, 0.39 and hyper plasticizer of 0.6%. 0.8%. 1.0%, 1.2% the cubes were cast and accordingly the cylinders were cast. For each ratio of water binder, 12 cubes and 2 cylinders were cast. Out of 12 cubes, 3 cubes were cured for 7 days, 3cubes for 15 days, 3 cubes for 21 days and the balance 3 cubes for 28 days. All the cubes were tested in a 2000kn compression testing machine. The load deflection curves, stress- strain curves were drawn for each cube and cylinder. The average compressive strength of each mix for different number of days of curing were calculated. The modulus of elasticity was calculated for each design mix.

The paper is devoted to the investigation of the seismic response of eccentrically braced frames characterised by links having different length. In addition, the analysed structures have been designed according to a methodology, already proposed by the authors, aiming to guarantee a collapse mechanism of global type. Therefore, the results of the nonlinear analyses herein presented provide the validation of the proposed design procedure, by testifying that all the designed structures exhibit a global failure mode where all the links are yielded while all the columns remain in elastic range with the exception of the base section of first storey columns, leading to high energy dissipation capacity and global ductility. Furthermore, two different distributions of the link lengths are examined. The first one is characterised by short links with uniform lengths along the height of the structure. The second one is characterised by the use of link elements having different length at the different storeys which are selected to assure the same value of the non-dimensional link length. The seismic response of EB-Frames with such distributions of the link length is investigated by means of both push-over analyses and dynamic non-linear analyses. The comparison of the performances is mainly carried out in terms of plastic hinges distribution, local ductility demand and frame lateral stiffness.

The manufacturing industry has experienced a great deal of improvement in efficiency and cost reductions throughout the last centuries. But although there have been improvements in the manufacturing industry, the principles and work methods in the construction industry have stood still for more than a hundred years. Based on principles of mass customization applied in the manufacturing industry, two cases of successful implementation of mass customization and modularization have been investigated as a means of showcasing the possibility to incorporate standardization in parts of the construction industry. The investigation examined two different companies that have standardized parts of a construction. One, Altan.dk, standardized the method for constructing balconies; and NCC Skakt standardized the construction of shafts.

Throughout the last centuries, the manufacturing industry has experienced great improvements in efficiency and cost reductions, but the same improvements have not taken place in the construction industry. Based on the principles of mass customization that are known from the manufacturing industry, a case study of one of the largest construction companies in Northern Europe was carried out according to the principles of action research. This approach was used to clarify whether potential exists for using the principles of mass customization to improve efficiency and minimize costs connected with the construction of buildings; and if so, what they are. The main technical solutions used for residential and office buildings were analyzed using a top-down approach. These solutions were identified and their relations mapped using a Product Variant Master (PVM). When a satisfactory overview was achieved of the major technical solutions, a configuration system was made. Such a system is often used to communicate findings from the PVM to the user. Through the work of constructing the PVM and the configuration system, it was found that a great potential exists for implementation. Based on the findings and experiences gathered throughout the process, the conclusion is that the principles of mass customization are best used in the construction industry if used with a top-down perspective.

Reinforced concrete slabs are a widely diffused structural solution either in Italy, or abroad; this for a series of advantages connected to their structural conception and their performances. However, this series of advantages is obtained as a result of proper design, especially oriented to appropriately sizing the thickness of the plate itself. Moreover, for flat structures with concentrated loads, as the case of flat slabs on punctual supports, phenomenon of punching can't be neglected, as it inevitably affects the structure and so it must be taken into account even in the early stages of the project. In this paper an attempt to evaluate the reliability of punching verifications has been made, referring to some in force regulations; this has been possible making a comparison between the mean resisting value of punching, obtained applying law prescription and the real collapse load for some columns belonging to a building that collapsed during the early stages of its construction. For the specific case study analyzed, there has been the opportunity to perform an on-site investigation, collecting a great amount of information regarding the mechanical properties of the used materials, the real positioning of the rebars in the structural elements, the real amount of concrete cover and so on. Since in a punching failure mechanism a crucial element is the resistance of the concrete, the precise definition of its properties attains great importance, especially when existing buildings are involved. To analyze the exact conditions of collapse and the factors that may have originated it, an important procedure is the acquisition of information, as much as possible, about the mechanical properties of the onsite materials. After this first evaluation of the accuracy of the actual regulations, another interesting comparison has been carried out, studying the influence of two main factors in the definition of the punching shear resistance; more specifically, it has been observed which is the contribution of the variability of the compressive strength of the concrete on site and the effective depth of the plate. The first related to a series of circumstances that may affect the value of the resistance, reducing it from that established during the design phase, the second closely related to inaccuracy in the laying of the longitudinal reinforcement. Therefore two sensitivity analysis have been performed, either referring to Eurocode 2, or following the prescriptions given in Model Code 2010, varying once the mean value of the compressive strength of the concrete, once the effective depth d.

This work designs a novel hydraulic-walking incremental launching equipment. The working principle of the equipment is proposed. Considering that the contact in incremental launching construction is a typical elastic contact problem, and changes in contact state will directly affect the stability of the incremental launching, this work proposes the equilibrium equations of computational contact mechanics and numerical analysis method for the incremental launching equipment through analyzing the working process of the equipments. The proposed model and method are applied in the analysis of typical working conditions of the incremental launching of Donghua Bridge. The structural characteristics in the construction process are analyzed and discussed. The analysis results show that the strength and stability of the steel box girder can meet the construction requirements. The incremental launching of Donghua Bridge was completed successfully. The proposed model and method can be used to predict and analyze the structural performance in incremental launching construction as well as provide theoretical reference and analysis method for similar constructions.

Infill walls have attracted the attention of many researchers since the early 1950's, and much work has been undertaken to study their behavior and interaction with the surrounding frames. In addition, efforts have been made to utilize infill walls as a means of producing economic designs by reducing the sizes of the members of the bounding frames. A large number of researchers have studied the behavior of infilled frames. It is evident through their studies that infill walls can provide both an economic and practical means for the lateral stability of framed structures and a viable alternative for retrofitting existing structures to resist seismic, wind, and blast loads. Despite this, there is reluctance from the engineering community to use this structural system widely and consider infill walls as structural elements due, firstly, to lack of knowledge concerning the composite behavior of infilled frames, and secondly, due to lack of practical methods for the stiffness and strength prediction. Therefore, although the subject of infilled frames has been studied for more than sixty years, there are still no definitive answers either about their behavior and interaction with the bounding frame or about the estimation of their stiffness and strength. Some problems that make it difficult for practicing engineers to use infill walls as structural elements are the inherent nonlinearity, and degradability of infill walls, as well as their high degree of variability. The fact that infill walls exhibit completely different in-plane and outof- plane behavior makes the problem even more difficult to tackle. The problem becomes even more complex when openings are present in infills that change their overall behavior, which is the rule rather than the exception. Consequently, two schools of thought in seismic resistant design have been formulated concerning infill walls. In the first, it is required that infills be effectively isolated structurally from the structural system, so that their structural effects can justifiably and correctly be neglected and in the second, infill walls are considered to be tightly placed and therefore, their interaction with the structural system to resist the effects of all kinds of excitations should be properly considered in the design, detailing and construction. Taking into consideration that a main principle for seismic-resistant design is: avoid unnecessary masses, and, if a mass is necessary, use it structurally to resist seismic effects, then the second philosophy offers more conceptual and practical advantages. Thus, if walls and partitions are needed and the economical material is masonry or concrete, attempts should be made to use these infills as structural elements. The proper use of infill elements can be of great practical value in the design of new or in the retrofitting of existing structures The large number of parameters that affect their behavior, the variability, nonlinearity and anisotropy of their properties, the large number of failure modes, which can be inplane or out-of-plane and are affected by the presence of openings, the interaction with the bounding frame, which affects the failure mode of the overall system, as well as many other factors, makes the numerical modeling of these systems very difficult. Both macro-modeling and micromodeling have been used to simulate the linear and nonlinear response of this complex system, in an effort to encapsulate its behavior and provide a tool for the analysis and design of such systems. Nevertheless, as yet, there is no definitive answer to the modeling of such systems, since the macromodels fail to follow the nonlinear sequence of failure of infilled frames and can therefore be used for obtaining upper or lower bound solutions, while the micro-models require too many parameters to be set, which are not always known, and are very computationally demanding to be used for everyday engineering work The above discussion reveals the difficulties associated with this problem and the need for more research to answer these long standing questions. Therefore, I consider timely the Special Issue on Infilled Frame Structures that the Open Construction & Building Technology Journal is publishing. The Co-Editor-in-Chief Panagiotis Asteris who has a significant contribution to the subject matter, has made an excellent effort in bringing together a group of distinguished scholars and researchers from several institutions in nine different countries located in three continents to present their work that covers the various aspects of infilled frames. I am certain that the present volume will lead to further insights, new research and developments in the subject area, thereby providing a valuable source of knowledge for students, researchers and practicing processionals