1. President FERO Corporation Edmonton, Alberta
2. Structural Engineer COSYN Technology Edmonton, Alberta
3. Ph.D. Student University of Alberta Edmonton, Alberta CANADA, T6G 2G7

ABSTRACT

With the incorporation of insulation in the cavity of masonry veneer wall assemblies, providing support for the exterior wythe or veneer wall has become very expensive. The continuity of the insulation and that of the air barrier has increasingly made it necessary to install an elaborate system consisting of a gusset plate fastened or welded to the main structural elements and an angle iron bolted or welded to the gusset plate.   This system is designed by a structural engineer and typically handled at the job site under miscellaneous iron at substantial cost. A new and innovative system for supporting masonry veneer is presented. The system requires no weld and thus allows installation to be performed by the masons. Out-of-plumb building tolerances can easily be accommodated during veneer construction to ensure the veneer is both plumb and has sufficient support by the shelf angle.

Veneer02

1. Professor
2. Ass. prof. Eindhoven University of Technology, Dep. of Structural Design, BKO, P.O. Box 513, Postvak 7, 5600 MB Eindhoven. The Netherlands.

ABSTRACT

In the Netherlands, a tendency is recognised to make more and more movement joints in veneer walls. Consequently, these walls act like rigid elements in which all deformation concentrates in the movement joints. In surrounding countries (e.g. Belgium) the spacing of vertical and horizontal movement joints is much larger. Questions that arise are: how much movement joints are needed to prevent cracking, and when cracks occur which crack width is acceptable?

The paper describes different crack-causing parameters, some explorative studies and several research items. An inventory of cracking in facades was made, as well as literature surveys concerning the shrinkage and temperature deformation of masonry walls [Vermeltfoort & Martens]. In order to determine the most critical areas in a veneer wall, the stress distribution in facades with and without movement joints was numerically simulated with the finite element program DIANA.

Based on the explorative studies, three proposals for fundamental research at PhD level are presented to study: a) the masonry stiffness aspects such as: how to make a soft mortar and the effect of open perpend joints, b) the execution aspects like stress distribution in and around lintels during building and c) the architectural aspects such as: detailing of walls, the use movement joints and crack-control.

PhD candidates are invited to reflect.

Key words: veneer wall, movement joint, cracking parameter

veneer01

1. PhD. Student in the Course of Civil Engineering, CPGEC/UFSC/BRAZIL E-mail: tatiana_amaral@hotmail.com

ABSTRACT

This paper presents a specific masonry training program based on quality, productivity, rationalization, hygiene and safety concepts. This paper revisits the systemic approach that brings into focus four different phases: diagnosis, programming and planning, execution and evaluation. Some concepts were developed according to a Brazilian method called SEMEAR, focused on participant teaching-learning techniques and based on the New Pedagogy principles. More important for ours purposes was stimulate a better verbal communication, improve the group relationship and call the attention to the need for a new professional posture.

The validity of this training program is demonstrated through two empirical examples. The results show that this specific training program represent a viable and effective tool to improve the understanding of services orders and to increase the interaction among construction workers. This training program can also be seen as part of a group of strategies that aims to answer the new patters of behavioral and attitudinal posture, recent requested by companies.

traing01

1. Professor,
2. Graduate Student Department of Civil Engineering, University of New Brunswick, P.O. Box 4400, Fredericton, NB, Canada E3B 5A3 E-Mail: BISCHOFF@UNB.CA

ABSTRACT

When designing reinforced masonry for strength, the contribution of tension in the masonry is typically neglected and the tensile forces are assumed to be resisted by the steel reinforcement. Although the masonry does not resist tension at a crack, it is still able to carry tension between the cracks through transfer of bond forces between the reinforcement and masonry. This effect is called tension stiffening, and it affects the deformation and stiffness of reinforced masonry elements where part of the element is under tension, such as beams or walls subjected to bending.

This paper describes the results of an experimental programme to investigate tension stiffening of reinforced masonry members under axial load. Half-block specimens six courses high are reinforced with either a single 15M or 20M bar and subjected to uniaxial tension. The load-deformation response of each member is compared with the bare steel response to observe the effects of tension stiffening for reinforced masonry under direct tension. Results are then used to determine the average tensile stress carried by the masonry after cracking (and before yielding of the reinforcing steel), which is compared with the average tensile strength of cracked concrete. This effectively provides a material model for cracked masonry, which can be useful for nonlinear analysis of reinforced masonry structures as well as for assessing serviceability requirements after cracking related to member stiffness, deformation and crack control. Analysis of the test data indicates that tension stiffening in masonry may be comparable to concrete, but results are affected by shrinkage and more work is required to validate this behaviour.

Key words: reinforced masonry, shrinkage, tension stiffening

TNSTIF01

1. Post Doctoral Researcher, 205 N Mathews Avenue, University of Illinois at UrbanaChampaign, 61801, nichols1@uiuc.edu
2. Hanson Engineers Professor of Civil Engineering and Director of the Mid-America Earthquake Center, University of Illinois at Urbana-Champaign, 205 N Mathews Avenue, Urbana, 61801, d-abrams@uiuc.edu

ABSTRACT

The Mid America Earthquake Center is a collaborative research center, established by seven participating core universities with funding from the National Science Foundation. The primary vision of the center is to reduce earthquake losses through research. Research at the Center is directed at improving seismic resistance through effective mitigation procedures. This results from the vulnerability of gravity-load designed buildings located in the eastern and central United States to an infrequent, but large future earthquake. A complementary program of research on earthquake resistant evaluation and rehabilitation for low-rise, unreinforced masonry buildings is underway at the MAE Center. This paper provides a summary of masonry-related research at the Mid-America Earthquake Center. It will include descriptions of experimental and computational research done to study seismic performance of unreinforced masonry building structures, and the effectiveness of various retrofit procedures. The summary will highlight:

• Behavior of unreinforced clay-unit masonry walls and piers behaving in shear or flexure and retrofitted with shotcrete, FRP and ferrocement coatings, and reinforced cores.
• Dynamic response of low-rise buildings with flexible floor diaphragms where dynamic stability of out-of-plane walls is a concern.
• Behavior of timber floor diaphragms retrofitted with various means.
• Three-dimensional behavior of a full-scale, two-story URM test structure subjected to simulated earthquake forces, and a corresponding half-scale replicate structure subjected to simulated earthquake motions.
• Response modification procedures for seismic retrofit of URM low-rise buildings. Each description will include statements as to the relevance of the research for impacting structural engineering practice through the updating of seismic codes and guidelines for reducing losses resulting from future earthquakes in the central and eastern United States.

Key words: Masonry Testing, URM Building, earthquakes, Mid America

seismc06

1. Research Assistant, Ph.D. Candidate, Mid-America Earthquake Center, University of Illinois, Urbana, IL 61801, simsir@uiuc.edu
2. Assistant Professor of Civil Engineering, University of Illinois, Urbana, IL 61801, aschheim@uiuc.edu
3. Hanson Engineers Professor of Civil Engineering, University of Illinois, Urbana, IL 61801; Center Director, Mid-America Earthquake Center, d-abrams@uiuc.edu

ABSTRACT

The paper concerns the seismic response of masonry buildings—in particular, the effects of diaphragm flexibility on the dynamic response of unreinforced masonry walls responding out of plane. Previous static and dynamic studies of out-of-plane response resulted in midheight or rocking collapse of the walls. These modes of failure were enforced by the test setups. No such failures resulted in the present tests, which were conducted on the earthquake simulator (shake-table) at the University of Illinois. In these tests, inertial loads were applied to the outof-plane walls through the diaphragm element. Different diaphragm stiffnesses and various earthquake ground motions were used. Results from this ongoing experimental study as well as an analytical method to determine the dynamic stability of the out-of-plane walls are reported.

This project is supported by the National Science Foundation through the Mid-America Earthquake Center.

Keywords: Unreinforced masonry, dynamic testing, out-of-plane wall, diaphragm flexibility.

SEISMC05

1. Research Structural Engineer, USAERDC, P.O. Box 9005, Champaign, Illinois 61826-9005 g-al-chaar@cecer.army.mil
2. Graduate Research Assistant, University of Illinois at Urbana-Champaign 1203 Clifford Dr., Apt. 5, Urbana, Illinois 61802   glamb@uiuc.edu
3. Hanson Engineers Professor of Civil Engineering,University of Illinois at Urbana-champaign 1245 Newmark Civil Engineering Laboratory, 205 North Mathews Avenue Urbana, Illinois 61801   d-abrams@uiuc.edu

ABSTRACT

Even with recent advancements in the analysis of masonry-infilled frames, the seismic behavior of this complex structural system is not fully understood. Therefore, a threestory, three-bay R/C frame with URM infill model was subjected to a series of in-plane lateral forces to better understand its performance under seismic excitation.

The test specimen was a half-scale model designed from a building constructed in the 1950’s. This building lacked the current seismic detailing typical of modern construction. A prescribed cyclic loading history placed displacement demands on the structure representative of those that are expected to occur during light, moderate, and strong earthquake motions. In this manner, knowledge of the behavior of this structural system under seismic loading was acquired.

Test results will be discussed in this paper with respect to measurements of strength, stiffness and deformation capacity as well as observed damage patterns and apparent performance limit states. Propagation of cracks in the concrete frame and masonry infill during the loading will be illustrated and discussed with respect to measured histories of force and deflection. Measured shear strains in each of the nine infill panels will also be correlated with the progression of damage to infer the distribution of lateral force to each infill panel.

Key words: Cyclic Loading, Multibay, Multistory, Reinforced Concrete, Seismic,     Stiffness, Strength, Unreinforced Masonry.

SEISMC04

1. Research Structural Engineer, USAERDC, P.O. Box 9005 Champaign, Illinois 61826-9005   g-al-chaar@cecer.army.mil
2. Hanson Engineers Professor of Civil Engineering University of Illinois at Urbana-Champaign 1245 Newmark Civil Engineering Laboratory, 205 North Mathews Avenue   Urbana, Illinois 61801     d-abrams@uiuc.edu

ABSTRACT

This paper summarizes analytical research on stiffness and capacity evaluation of non-ductile reinforced concrete frames with masonry infill panels performed at the US Army Corps of Engineers Construction Engineering Research Laboratory. A series of nonlinear finite element analyses were completed to investigate sensitivities in behavior attributable to various design parameters. Computational simulation models were calibrated with measured data from one-story reinforced concrete frames containing one, two, and three bays. These frames were braced with either masonry or brick infill. The infill-frame structures were constructed at half-scale and subjected to lateral in-plane displacements. Modeling procedures and computed results from this investigation are summarized in this paper.

Finite element models can be employed to supplement expensive testing of large physical models provided that proper simulation exists. Once results of experimental and computational simulations are calibrated, analyses of a large array of different building configurations can be done to investigate plausible concepts for design, evaluation or rehabilitation of actual structures. Research described in this paper addresses variables significant to the determination of ultimate strength and deformation capacities for concrete frames with solid infills, and their sensitivities to variations in material properties and configuration. As well, results of this series of analyses address important variables found in laboratory tests of infill-frame systems, such as mortar type, infill type, load application points, and load distribution.

Key words: Masonry infill, non-ductile reinforced concrete frames, capacity evaluation, inplane capacity, multi-story buildings, multi-bay buildings, reduction in shear capacity due to openings, experimental and finite element study.

seismc03

Laboratory of Strength of Materials and Laboratory of Reinforced Concrete, Department of Civil Engineering Aristotle University, Thessaloniki 54006, Greece. Fax: 003031 995769, email: gcmanos@civil.auth.gr.

ABSTRACT

The earthquake performance of partially reinforced masonry piers when subjected to seismic loading is examined here in the framework of an extensive experimental investigation. The objective is to be able to construct earthquake resistant low-rise partially reinforced masonry buildings in areas of moderate seismicity of Greece. This paper includes an overview of the earthquake performance of partially reinforced piers employing a “Greek” type brick, which is developed and manufactured by Filippou Structural Clay Products and is now available from their industrial production facility. Almost all the brick units employed in the framework of the current research program were produced by this industrial process; similarly the rest of the materials employed in the construction of the examined masonry piers are also available in the current construction practice in Greece. This research has been conducted at the Department of Civil Engineering, Aristotle University and was under the financial support of the Greek Ministry of Energy and Industry, General Secretariat of Research and Technology.

Key words: Partially reinforced masonry, Earthquake performance, In-plane cyclic loading

SEISMC02

1. Prof., Inst. of Struct. Anal. and Aseismic Res., Nat. Tech. Univ. of Athens, Zografou Campus, GR-15773, Athens, Greece.
2. Res. Asst., Inst. of Struct. Anal. and Aseismic Res., Nat. Tech. Univ. of Athens, Zografou Campus, GR-15773, Athens, Greece.

ABSTRACT

In this paper, the seismic behaviour of multistory, reinforced concrete, partially infilled frames is investigated. Using the Method of Contact Points for the analysis of masonry infilled frames, the influence of the masonry infill panel opening in the variation (reduction) of the infilled frames stiffness has been investigated. A parametric study is carried out using as parameters, the area and the position of the masonry infill panel opening. The investigation has been extended to the case of soft stories, where infill does not exist.

Key words: Infilled frames, masonry wall, seismic response, soft story.

SEISMC01