Precast Concrete Cladding Research Articles

Improving the operational reliability and safety of channels in precast concrete cladding on substandard aggregates

The article is devoted to the problem of safety and reliability of water management systems. Most of these systems in the North Caucasus are in unsatisfactory condition, which leads to a rise in the groundwater level, salinization and contamination of adjacent lands, flooding of territories, pollution of places of residence and a decrease in the standard of living of the population. For the repair and restoration of systems and prevention of environmental damage to environmental components, by reducing filtration losses, both under normal operating conditions and under seismic impacts, precast concrete elements on inexpensive non-composite aggregates are proposed. Despite their (aggregates) relatively low quality and availability, concretes and trays, pipes and slabs made of it are characterized by a high resource-saving effect and meet the requirements of safety and reliability. This is achieved by adding a formiate-alcohol plasticizer to the concrete mixture, which has a super-liquefying effect that reduces the water consumption of the concrete mixture (water-reducing effect) and increasing the construction, technical and operational properties, including the reduction of seismic activity. The recommended proposals will significantly reduce the losses of water supplied to consumers, both in normal and extreme operating conditions, prevent flooding, pollution and waterlogging of adjacent territories, and improve the living conditions of the population.

Seismic performance of precast concrete frame with energy dissipative cladding panel system: Half-scale test and numerical analysis

An energy dissipative cladding panel system was proposed for large precast concrete cladding panels in multi-story buildings. A six-story, three-span planar prototype frame structure with energy dissipative cladding panel was designed to evaluate the seismic performance and damage control effects of the precast concrete frame with the proposed energy dissipative cladding panel system. The bottom two stories of the middle span were selected as the test substructure and were tested under cyclic loading. The damage evolution mode and seismic performance of this structure were identified. A numerical simulation method was recommended for such a structure based on the damage characteristics observed in the two-story substructure, and validated against the test results. The seismic responses of the six-story prototype frame structure with and without the energy dissipative cladding panel were then compared through nonlinear time-history analyses under near- and far-field ground motions. The analysis results indicated that the maximum inter-story drift ratios of the precast concrete frame with energy dissipative cladding panel were 23.8%–35.2% and 19.8%–41.6% lower than those of the bare precast concrete frame under far- and near-field ground motions, respectively. The maximum inter-story drift ratios of the precast concrete frame with energy dissipative cladding panel under near-field motions were 1.72 and 1.76 times those under far-field motions under the maximum considered and very rare earthquakes, respectively.

Seismic and collapse performance of a hybrid structure comprising steel frame with precast concrete shear walls and cladding panels

AbstractA hybrid structure constructed by replacing external steel beams and columns in the steel frame (SF) to precast concrete shear walls with insulation (PCSWs) and precast concrete cladding panels (PCCPs, SFPCSW) is proposed in this paper to avoid the problem of columns protruding from walls and PCCPs directly connected with SF. Numerical models of the SF and SFPCSW structures are established in ETABS software based on an 18‐story assembled steel residential building to investigate the seismic performance and collapse resistance capacity of SFPCSW. Time history analysis results show that the SFPCSW exhibits bending‐shearing lateral deformation and has more uniform interstory drift ratios than the SF. Under major earthquakes (i.e., probability of exceedance of 2% in 50 years), the damage of SF is concentrated in stories 1–6; for SFPCSW, the plastic hinges mainly appear in the concrete beams between PCSWs at each story, and the damage in PCSWs and the internal frame is small. Using pinned connections between the steel beam and PCSW reduces the structural lateral stiffness and increases the earthquake load carried by the internal frame. The incremental dynamic analysis results show that the SF and SFPCSW have similar collapse resistance capacities.

Cyclic Behaviour of Two-Story Low-Damage Rocking Precast Concrete Cladding Panel System

ABSTRACT This paper presents the bidirectional (in-plane and out-of-plane) cyclic performance of two-storied precast concrete cladding panel assemblies designed to accommodate, through a ‘rocking’ mechanism, in-plane and out-of-plane inter-story drifts expected in major earthquakes. Two sub-assemblies comprising four rocking precast concrete panels oriented parallel and perpendicular to the loading direction were subjected to quasi-static lateral cyclic inter-story drift demands. The test results show the ability of slotted rocking connections to accommodate the designed 2.00% inter-story drift without any noticeable damage to the panels or their connections. The only damage observed was the partial detachment of the sealant along the bond-line between the panels at 1.40% drift, possibly because of the test being conducted prematurely (only in 9 days) before the sealant had fully cured, and a relatively weak adhesion due to inadequate cleaning of the dusty concrete panel surfaces before the sealant was applied.

Lessons for loss assessment from the Canterbury earthquakes: a 22-storey building

By comparing damage and loss predictions with those observed for a 22-storey steel building with eccentrically based frames (EBF) that underwent the Canterbury earthquakes, this paper gauges the performance and explores the benefits of applying the PEER performance-based earthquake engineering assessment procedure. The study shows that steel EBF repair costs are significantly affected by the work required to remove and reinstate non-structural elements in order to access the steel structure. It is therefore concluded that the location of non-structural elements relative to structural elements should be considered in the seismic design of new buildings and within loss assessment procedures. Two retrofit and/or rehabilitation options are considered for the building; improving the deformation capacity of drywall partitions, and re-detailing the exterior cladding connections to better accommodate structural deformations. The findings show that, for the specific building, improving the drywall partitions should lead to a reduction in expected annual losses whereas the use of improved detailing for the precast concrete cladding would not. This suggests a general strategy for cost-effective decisions might be to focus on increasing the performance of the most vulnerable components (plasterboard partition walls, in this case). An examination of the potential effects of aftershocks to the selection of cost-effective options adds support to this conclusion. Aftershocks are found to increase the predicted losses by around 10%, emphasizing the need to consider aftershocks when assessing expected annual losses due to earthquakes.

A multi-criteria decision-making model for selecting curtain wall systems in office buildings

PurposeThe purpose of this paper is to develop a model that facilitates the evaluation and selection processes of curtain wall systems used in office buildings.Design/methodology/approachA comprehensive literature review and interviews with local experts were conducted to identify common types of curtain wall systems used in office buildings and their selection criteria. A questionnaire was designed and completed using multi-criteria decision-making techniques through face-to-face meetings with consultants in the Eastern Province of Saudi Arabia. The proposed model was implemented in prototype software as a proof of concept.FindingsThe results revealed that fire resistance scored the highest weighting of all the criteria. Furthermore, precast concrete cladding panels were found to be the best system for use in office buildings located in the Eastern Province of Saudi Arabia. The model validation reveals that the score for any curtain wall system varies depending on the nature of the project and that the prioritisation of criteria can vary from one practitioner to another.Originality/valueThe model captures the knowledge of professionals who are experts in the prioritisation of criteria for selecting curtain wall systems. The research design presented expands the boundaries of knowledge of the relevant literature, through demonstrating a conceptual framework incorporating different techniques into a computerised model. It has practical implications through presenting a systematic procedure for developing and adopting a computerised decision-making tool, which aligns experts’ professional practice and requirements, for use in selecting fragmented options.

Flexural performance of non-loadbearing blast-resistant precast concrete cladding panels with discrete connections

Boundary conditions of non-loadbearing precast concrete cladding panels differ from monolithic cast-in-place walls by relying on discrete connections for attachment to the main structural system, typically at the floor diaphragms. When the panels are designed to resist far-field blast loading, discrete connections at the diaphragms are commonly idealized as horizontal lines of continuous support, with cladding panels are analyzed assuming vertical (primary) one-way flexural behavior. Two-way or horizontal (transverse) one-way flexural response can realistically occur with variations in reinforcement layout or connection spacing; however, these modes of flexural response are typically neglected in conventional design approaches but could severely limit a panel's flexural ductility and capacity. In this paper, a validated nonlinear finite element model is used to conduct a comprehensive parametric study of the flexural responses of solid non-loadbearing precast concrete façade panels with discrete connections subjected to uniform lateral (normal) pressure. Sensitivity of ultimate flexural capacity based on discrete boundary conditions is examined for different ratios of primary to transverse reinforcement as well as different vertical-to-horizontal span aspect ratios. Models with discrete connections were able to achieve a vertical mechanism by either decreasing the ratio of vertical-to-horizontal flexural capacity and/or increasing the number of lateral connections (thereby reducing the horizontal span between connections). For panels with vertical-to-horizontal span aspect ratios near 1.0, a vertical-to-horizontal flexural capacity ratio of 0.5 was needed to develop the vertical plastic mechanism. For panels with vertical-to-horizontal span aspect ratios greater than 1.5, a vertical-to-horizontal flexural capacity ratio of 1.0 was needed to develop the vertical plastic mechanism.

Seismic accelerations in architectural precast concrete cladding

Architectural precast concrete (APC) cladding is a type of building facade broadly used worldwide. It is composed of an array of concrete panels attached to the building structural system with steel connections. During earthquakes, the APC system can be damaged both by excessive drifts and accelerations. While research on drift-compatibility has been performed in recent years, to the author’s knowledge there are limited studies aimed to determining the level of seismic forces in APC cladding panels and connections. However, these forces could be larger than anticipated since this system has low natural frequencies due to its large mass and low stiffness in the out-of-plane direction.This paper presents an experimental and numerical study of the seismic accelerations developed in APC cladding panels installed on a building. The design limits provided by the code for ductile and brittle elements of the cladding system indicate that the code is able to meet the desired performance criteria both in case of service and design level motions. However, the satisfactory results obtained for design level earthquakes are due to the combination of significant errors in the prediction of the component and structure amplification factors.

Evaluation of fragility functions with potential relevance for use in New Zealand

One barrier to adopting seismic loss estimation frameworks in New Zealand engineering practice is the lack of relevant fragility functions which provide probabilities of exceeding certain levels of damage (e.g. cracking of gypsum wallboards) for a given demand (e.g. interstorey drifts). This study seeks to address this need for four different building components; interior full-height steel-framed plasterboard partition walls, unbraced suspended ceilings, precast concrete cladding, and steel beam-column joints with extended bolted end-plate connections. Fragility functions were sourced from literature, and their potential for use in New Zealand is evaluated considering similarities in component detailing with local practices. Modifications to a number of fragility functions, including generalizations for easier adoption in practice, are proposed. A loss estimation case study of a 4-storey steel moment-resisting frame is performed to investigate the significance of fragility function selection. It is shown that the definition of damage states can have a noticeable influence on the assessment of incurred repair cost of individual building components. This indicates that fragility functions should be carefully selected, particularly if the performance evaluation of each individual component is of utmost importance. However, the observed difference in expected annual repair cost of the entire building was small, indicating that in cases where fragility functions are not readily applicable for use in New Zealand, other fragility functions may be used as placeholders without drastically altering the outcome of loss analysis for the entire building.

Project Spotlight: Precast concrete cladding saves time and money in Ohio parking structure

The Tri-C district parking structure at Cuyahoga Community College in Cleveland, Ohio, used precast concrete for faster and easier construction of the facade. Sidley Precast Group in Thompson, Ohio,was the firm selected for the precast concrete portion of the project.

Experimental investigation of the response of precast concrete cladding panels with integrated connections under monotonic and cyclic loading

One major issue in the design of precast structures against earthquakes is the importance of cladding connections on the overall response. In the present work, an experimental investigation on the monotonic and cyclic behaviour of fixed panel connections, also referred as ‘integrated’ connections, is reported. The extensive experimental program was performed at the Laboratory for Earthquake Engineering of the National Technical University of Athens, Greece, within the framework of the FP7 European project SAFECLADDING, and aimed at the investigation of the behaviour of several types of connections materialized with vertical reinforcement bars, referred as ‘rebar’ connections, or steel mechanisms of two types: ‘wall shoe’ and ‘steel plate’. The results show that rebar and wall shoe connections can attain large ductility and strength, but with significant pinching for large lateral displacements, due to the plastic deformation of the connections’ rods that can lead even to residual joint opening. When this happens, apart from the horizontal slip that can occur, the energy dissipated decreases, as evident from the corresponding normalized energy dissipation capacity curves of the tested specimens. The damage to the panels observed during the tests was generally limited, except of large drifts combined with strong connections, and the overall failure was determined by the failure of the connectors.

Concrete solar collectors for façade integration: An experimental and numerical investigation

Precast concrete cladding systems can be converted into concrete solar collectors by embedding pipes within the exposed concrete, providing a unique building integrated solar thermal solution. Past research of non-integrated, roof-attached concrete solar collectors have largely focused on experimental studies in high temperature climates and/or simulation studies using simplified 1D and 2D models. This study (1) Experimentally investigates the performance of a façade integrated concrete solar collector in a mid-latitude European climate (Dublin) and (2) Develops and validates a 3D numerical model which is then used to predict the performance of other façade integrated concrete solar collectors in other European climates. The study primarily quantifies the performance in relation to the energy output and the solar fraction. The experimental set-up of the concrete solar collector is designed to represent a south facing façade installation. The experimental results showed that one quarter of the annual hot water demand of a single occupant dwelling could be provided using 1m2 of concrete solar collectors with spring and autumn months producing the highest daily energy outputs; attributed to the vertical orientation of the concrete solar collectors. A 3D numerical model of the vertically installed concrete solar collector is developed in COMSOL Multiphysics and validated against the experimentally measured results. The validated model is used to expand the study to different collectors and systems, as well as two additional contrasting Northern and Southern European climates where precast concrete is a popular cladding material, namely Helsinki and Sofia. The simulation results showed that the solar absorptance, flow rate, collector area and pipe length have a significant influence on the performance of the concrete solar collector system. Annual solar fractions of 20% (Helsinki), 24% (Dublin) and 30% (Sofia) are predicted for a small apartment building using a façade integrated concrete solar collector. The concrete solar collectors presented a negligible influence on the interior environment provided sufficient insulation is located at the back of the concrete absorber, as would be typical of a precast concrete sandwich panel construction.

Evaluation of out‐of‐plane seismic performance of column‐to‐column precast concrete cladding panels in one‐storey industrial buildings

SummaryRecent earthquakes in Italy (L'Aquila 2009 and Emilia 2012) highlighted the vulnerability of precast cladding panels, typically associated with a connection system not designed to account for displacement and rotation compatibility between the panels and the supporting structure. Experimental investigations were performed in the past to investigate the in‐plane performance of cladding panels and design recommendations have been made accordingly; however, in the case of out‐of‐plane seismic loads, the load demand is commonly evaluated in the design practice by means of formulations for nonstructural components.This paper summarizes the results obtained from parametric analyses conducted to estimate the out‐of‐plane load demand in column‐to‐column cladding panels typical of one‐storey commercial and industrial buildings. Empirical equations suitable for both new and existing panels are proposed and compared with the design equations given in Eurocode 8 and ASCE 7. The paper also considers the effects of the development of plastic hinges at the column base and of the roof flexibility on the load demand in panel‐to‐column connections. The roof flexibility may generate the torsion of the panels; consequently, an analytical procedure to account for such effects is proposed. Finally, general design recommendations are made.

Parametric investigation of concrete solar collectors for façade integration

Concrete solar collectors are a cheap and durable option for solar thermal energy harvesting for hot water and space heating applications. They offer a unique facade integrated solar thermal solution, allowing for seamless integration with precast concrete cladding systems. The thermal energy output of a concrete solar collector is dictated by its material (thermal conductivity and specific heat capacity of concrete and pipe), geometry (pipe spacing, pipe diameter, collector thickness, pipe embedment depth) surface finish (absorptance and emittance) and fluid flow. Given the wide range of individual parameter values documented in the literature an investigation into these parameters is required. In this work concrete solar collectors are simulated using an experimentally validated 2D finite element model computed in COMSOL Multiphysics. Outlet fluid temperatures up to 40°C and a daily efficiency of 56% are predicted for a clear summer day in Ireland using the model for a reference case concrete solar collector. Concrete solar collectors compare well with other unglazed collectors (metallic absorber; daily efficiency=62%) and (polymer absorber; daily efficiency=29%). Parameters are investigated individually and compared collectively within the range of values found in the literature. Concrete conductivity and solar absorptance are highlighted as two influential performance parameters which can be improved and are subsequently investigated experimentally. Additionally, geometric parameters, including the embedment depth and pipe spacing are identified as key performance parameters. These material and geometric parameters are limited by practical, economic and aesthetical constraints. These limitations are also examined and summarised.

Experimental Investigation on Steel W-Shaped Folded Plate Dissipative Connectors for Horizontal Precast Concrete Cladding Panels

ABSTRACTA dissipative connector device, consisting of a steel plate folded at right angle along three lines to get a W-shaped profile, is proposed for the safe fastening of the horizontal cladding panels of new or existing precast structures under seismic action. Experimental tests are carried out to characterize the hysteretic behavior of the connector device. Different technological features, restraint conditions, and loading protocols are considered. Nonlinear hysteretic models are validated against the results of pseudo-dynamic tests on a full-scale prototype of precast building with cladding panels. Guidelines for the design of the dissipative connector device are provided.

Data from the Network for Earthquake Engineering Simulation/E-Defense Collaborative Test Program on Innovative Isolation Systems and Nonstructural Components

The data sets generated from E-Defense shake table experiments of a full-scale, five-story building tested with two innovative isolation systems and in the fixed-base configuration are available in the Network for Earthquake Engineering Simulation (NEES) Project Warehouse. The experiments included an integrated subassemblage of partition walls, suspended ceilings, and sprinkler piping on the fourth and fifth floors of the building; a full-story precast concrete cladding column cover; and enclosed areas staged with building contents. Totaling approximately 211 GB between three experiments, the data set includes isolator forces and displacements, floor accelerations, and story drifts, local accelerations, and relative displacements at strategic locations on the nonstructural components, as well as extensive videos and inspection photos. The project was a collaboration between U.S. researchers of the NEES Tools for Isolation and Protective Systems (TIPS) and NEES Nonstructural Grand Challenge projects and Japanese researchers from the National Research Institute of Earth Science and Disaster Prevention. Data set DOIs are 10.4231/D3X34MR7R, 10.4231/D3SB3WZ43, and 10.4231/D3NP1WJ3P.

Blast resistant design of precast reinforced concrete walls for strategic infrastructures under uncertainty

Extreme loads can have devastating effects on civilian structures since these buildings are not designed to withstand extreme events. Typical buildings and other critical infrastructures are particularly prone to external man-made attacks. This study focuses on probabilistic analyses, and investigates the probability of exceeding a given limit state of a precast concrete wall subjected to blast loads. The wall under investigation is a non-load bearing precast concrete panel used as exterior cladding for buildings. From the blast design point of view, these walls must protect people and equipment from external detonations. The aim of the paper is to compute both the fragility curves and the probability of exceedance of a typical precast concrete cladding system, considering a prescribed detonation of a vehicle borne improvised explosive device. To this aim non-linear dynamic analyses are carried out by the widely adopted equivalent single degree of freedom method. The fragility curves and the probability of exceedance of the precast concrete cladding wall are computed using Monte Carlo simulations.

Blast Resistance Assessment of Concrete Wall Panels: Experimental and Numerical Investigations

The cladding system of a building is crucial for protecting people and equipment against external explosions. Both experimental and numerical investigations are carried out in order to evaluate the resistance of precast concrete cladding wall panels against man-made attacks. The cladding system under investigation is a precast concrete wall panel for using in police station facilities that particularly need to be protected against man-made or subversive attacks. A total of three precast concrete cladding wall panels are studied. The panels are 3500 mm long and 1500 mm wide; and one is 150 mm thick while the other two are 200 mm thick. The longitudinal reinforcement consists of a single layer of reinforcement bars located in the middle of the cross section. The blast demand is due to the detonation of 3.5 and 5.5 kg of TNTeq, and the numerical simulations are carried out using the finite element software LS-Dyna©. Details of the experimental and numerical investigations are shown, and a discussion on the obtained results is provided.

Introduction of an Innovative Cladding Panel System for Multi-Story Buildings

An Energy Dissipating Cladding System has been developed for use in buildings designed based on the concept of damage-controlled structure in seismic design. This innovative cladding panel system is capable of functioning both as a structural brace, as well as a source of energy dissipation, without demanding inelastic action and ductility from the basic lateral force resisting system. The structural systems of many modern buildings typically have large openings to accommodate glazing systems, and a popular type of construction uses spandrel precast cladding panels at each floor level that supports strip window systems. The present study focuses on developing spandrel type precast concrete cladding panels as supplementary energy dissipating devices that are added to the basic structural system. Through a series of analytical studies, the result of evaluating the ability of the proposed Energy Dissipating Cladding system to improve the earthquake resistance of the buildings is presented here.

Fragility analysis for the Performance-Based Design of cladding wall panels subjected to blast load

This paper presents a probabilistic method to support the design of cladding wall systems subjected to blast loads. The proposed method is based on the broadly adopted fragility analysis method (conditional approach), widely used in Performance-Based Design procedures for structures subjected to natural hazards like earthquake and wind. The cladding wall system under investigation is composed by non-load bearing precast concrete wall panels. From the blast design point of view, these wall panels must protect people and equipment from external detonations. The aim of this research is to compute both the fragility curves and the limit states exceedance probability of a typical precast concrete cladding wall panel considering the detonations of vehicle borne improvised explosive devices. Moreover, the limit states exceedance probability of the cladding wall panel is estimated by Monte Carlo simulation (unconditional approach) in order to validate the proposed fragility curves.