Astm stp 1512 2010

Journal of ASTM International Selected Technical Papers STP1512 Masonry JAI Guest Editors: Jamie Farny William L Behie ASTM International 100 Barr Harbor Drive PO Box C700 West Conshohocken, PA 19428-2959 Printed in the U.S.A ASTM Stock #: STP1512 Library of Congress Cataloging-in-Publication Data Masonry / JAI guest editors: Jamie Farny, William L Behie p cm (Journal of ASTM International selected technical papers; STP1512) “This compilation contains only the papers published in JAI that were presented at a symposium in St Louis, MO, June 8, 2010 and sponsored by ASTM Committees COI on Cement, C07 on Lime, C12 on Mortars and Grouts for Unit Masonry, and C15 on Manufactured Masonry Units’’ Foreword Reprinted from JAI, Vol 7, No Includes bibliographical references and index ISBN 978-0-8031-3424-9 (alk paper) Masonry Congresses Masonry Materials Congresses I Farny, James A., 1962II Behie, William L TA670.M326 2010 693’.1 dc22 2010030872 Copyright © 2010 ASTM INTERNATIONAL, West Conshohocken, PA All rights reserved This material may not be reproduced or copied, in whole or in part, in any printed, mechanical, electronic, film, or other distribution and storage media, without the written consent of the publisher Journal of ASTM International „JAI… Scope The JAI is a multi-disciplinary forum to serve the international scientific and engineering community through the timely publication of the results of original research and critical review articles in the physical and life sciences and engineering technologies These peer-reviewed papers cover diverse topics relevant to the science and research that establish the foundation for standards development within ASTM International Photocopy Rights Authorization to photocopy items for internal, personal, or educational classroom use, or the internal, personal, or educational classroom use of specific clients, is granted by ASTM International provided that the appropriate fee is paid to ASTM International, 100 Barr Harbor Drive, P.O Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9634; online: http://www.astm.org/copyright The Society is not responsible, as a body, for the statements and opinions expressed in this publication ASTM International does not endorse any products represented in this publication Peer Review Policy Each paper published in this volume was evaluated by two peer reviewers and at least one editor The authors addressed all of the reviewers’ comments to the satisfaction of both the technical editor(s) and the ASTM International Committee on Publications The quality of the papers in this publication reflects not only the obvious efforts of the authors and the technical editor(s), but also the work of the peer reviewers In keeping with long-standing publication practices, ASTM International maintains the anonymity of the peer reviewers The ASTM International Committee on Publications acknowledges with appreciation their dedication and contribution of time and effort on behalf of ASTM International Citation of Papers When citing papers from this publication, the appropriate citation includes the paper authors, “paper title’’, J ASTM Intl., volume and number, Paper doi, ASTM International, West Conshohocken, PA, Paper, year listed in the footnote of the paper A citation is provided as a footnote on page one of each paper Printed in Bridgeport, NJ September, 2010 Foreword THIS COMPILATION OF THE JOURNAL OF ASTM INTERNATIONAL (JAI), STP1512, on Masonry, contains only the papers published in JAI that were presented at a symposium in St Louis, MO, June 8, 2010 and sponsored by ASTM Committees C01 on Cement, C07 on Lime, C12 on Mortars and Grouts for Unit Masonry, and C15 on Manufactured Masonry Units The JAI Guest Editors are Jamie Farny, Portland Cement Association, Skokie, IL, USA and William L Behie, Holcim, Huntersville, NC, USA Contents Overview vii Water Management and Efflorescence Efflorescence: Evaluation of Published Test Methods for Brick and Efforts to Develop a Masonry Assembly Test Method I R Chin and B Behie Test Method for Determining the Efflorescence Potential of Masonry Materials Based on Soluble Salt Content J P Sanders and D A Brosnan 14 Detailing Masonry Veneer/Steel Stud Backup Systems at Fenestration Systems to Avoid Moisture Problems N V Krogstad, R A Weber, and M J Huhtala 32 A Laboratory Evaluation of Plastic „Stucco… Cement-Based Plaster as a Barrier to Water Penetration of Concrete Masonry Construction at Hurricane Force Wind Speeds R T Flynn and J Gulde 55 Strength and Freeze-Thaw Testing Statistical Analysis of Flexural Tensile Strength of Clay Masonry as a Function of Void Area R M Bennett, J P Sanders, and J Bryja 71 Comparative Study of Freeze and Thaw Test Procedures on Molded Brick R A Cyphers and A R Whitlock 78 Proposed Masonry Specified Compressive Strength Requirements R M Bennett 90 Performance and Failure Analysis and Repairs Seismic Performance Tests of Masonry and Masonry Veneer R E Klingner, P B Shing, W M McGinley, D I McLean, H Okail, and S Jo 103 Improving the Thermal Resistance of Brick Masonry Systems J P Sanders and D A Brosnan 134 Evaluation and Repair of Thin Brick Veneer Facades J L Leafblad and C L Searls 147 Design and Use of Expansion Joints in New and Existing Clay Masonry Wall Systems M C Farmer and E A Gerns 170 Common Sense and Masonry Repair K A Pashina and S M Talafous 196 Overview Whether used as veneer, as a structural system, or as both, masonry has served people well for a long time Yet materials and systems are continuously evolving Through testing, research programs, and forensic evaluations, it’s possible to analyze what works well, where improvements can be made, and what techniques can make masonry systems more robust so that they are better able to perform their intended function Since moisture plays a key role, keeping water out of the structure is a top priority—whether for interior comfort, to keep occupants dry; for structural durability, to reduce the opportunity for rust and degradation; or for aesthetics, to minimize potential for efflorescence and otherwise maintain a pleasing appearance Testing and research are critical tools to study physical performance of masonry assemblies, including various aspects of strength and durability And ultimately, it’s important to use common sense in the way we design, build, and repair masonry construction The 12 papers contained in this STP address these issues and more, adding to the body of knowledge of masonry The information can be used to improve new and old installations so that masonry attains its top performance, both structurally and aesthetically Jamie Farny Portland Cement Association Skokie, IL William L Behie Holcim Huntersville, NC vii WATER MANAGEMENT AND EFFLORESCENCE PASHINA AND TALAFOUS, doi:10.1520/JAI102727 203 FIG 5—Existing shelf angles were left in place, even though there was no through-wall flashing or other protection • Veneer ties and anchors have evolved from plain steel to galvanized to stainless steel and variations thereof Expected corrosion effects need to be consistent with design life considerations • Flashing materials have gone from traditional methods 共i.e., copper, lead, or other metals兲 to faster-cheaper materials Many choices are available to the repair designer, but their limitations must be carefully considered Plastics are common for relatively shorter life expectancy repairs, and not all of these materials are durable Some have failed prematurely For example, plastic flashings of the 1970s 共PVC兲, when exposed during pre-repair examination, often are brittle, cracked, and split, often into the wall cavity and beyond If a long-term life expectancy is to be attained, materials that are more durable need to be used • Additives for mortars and manufactured units need to be evaluated carefully for use Not all additives are stable over the life of the repair, and sometimes they can be deleterious to the masonry wall As an example, in the 1970s, a well-known additive was promoted and used to enhance masonry bond strength, often for panelized-type construction Subsequently, it was discovered the additive was contributing to release of chloride ions, associated with extensive corrosion to embedded ferrous metals Not all walls constructed with this material experienced these problems, and many wall systems with this material are still in service The selection of the masonry type has also led to problems Such is the case with Carrara marble, which is prone to hysteresis when several conditions have to occur simultaneously 共a “perfect storm”兲 • A significantly great enough thermal gradient has to be present between the front and backside of the stone 204 JAI • STP 1512 ON MASONRY • The stone has to be sufficiently thin so that when grain re-orientation occurs, resulting volume changes occur, without the restraint afforded by thick sections of marble This is why this problem was not observed until thinner exterior Carrara marble-cladding panel systems became available Material manufacturers have strived to innovate with new materials and processes for the repair market When repairing a building, a specifier contemplating the use of any manufactured repair material must carefully consider the future performance of the product This is difficult when a product is newly manufactured and is intended to perform for decades During repair of buildings, it is typical for repairs to be limited to discrete areas, and the majority of the field of masonry is left in place 共an exception would be re-cladding the exterior, which is a smaller percentage of the overall projects being repaired兲 As shown above for the cases of PVC flashings and the use of thin Carrara marble panels, with innovation come growing pains Specifiers must use common sense in evaluating new-to-market materials and not “go all in” right away—or be prepared for the consequences Many times the reality of a building owner’s budget does not align with their expectations Compromises need to be made on nearly every repair project and distinctly communicated with the owner, so they are aware of their choices One means of resolving a budgetary problem is by providing an owner with a repair life that is compatible with their budget Such choices can be provided during the pre-design services stage of a project Shorter, medium, and longer term repair approaches can be presented with their estimated costs for comparison The differences between the approaches typically are a combination of the following • Extent of repair: Some areas of the masonry might not require repair until the life expectancy of the repair approach is exhausted Delaying repairs that otherwise would be undertaken with a longer life repair approach is a consideration • Repair methods: One example is the use of Dutchman replacement during stone repair versus an architectural repair mortar patch Varying combinations of amounts of repair types can also be considered and are appropriate One recent marble-clad structure was eventually repaired at spalled and cracked panels by repairing 30 % of the stone spalls using architectural repair mortar, 40 % by Dutchman replacement, and the remainder by full piece replacement 共Fig 6兲 • Material type: Stainless steel versus galvanized steel shelf angles and anchors will likely have potentially large differences in their performance over the life of the repair Owners should also be made aware that differing maintenance costs are associated with each various repair approach 共method兲 and can influence the selection Factors such as cash flow, interest rates, time to completion, and other considerations influence the selection of a repair approach and in turn material selections PASHINA AND TALAFOUS, doi:10.1520/JAI102727 205 FIG 6—Marble Dutchman repair matches adjacent stone very closely Inadequate Management of Water/Moisture Entering the Masonry Our experience has been that water leakage into occupied buildings is usually the flaw that is most likely to get the owner’s attention! However, it is often the case that water may be entering, entrapped, or otherwise moving inappropriately within the wall system long before distress is visible inside the building • Exterior masonry construction has steadily evolved over the years from barrier to cavity to rain screen walls Water management in each is vastly different, and there is a large stock of buildings of various ages and design types in regard to how they manage water entry • Some drainage cavity walls have inherent design problems that are now recognized by the masonry industry The earlier designs tended to have narrow, bridged cavities that were often ineffective Newer designs are much more effective, but there is a huge inventory of older buildings out there with built-in flaws 共Fig 7兲 Some of the older building exterior masonry wythes are tied to the interior wythes using header courses, which bridge the cavity and allow water migration from the outer to inner wythes • Flashing is commonly misunderstood and incorrectly installed • It may be terminated incorrectly, such as with reverse laps directing water into veneer below, cut back too short at the bottom leg of shelf angles, or not fully extended around shelf angle anchors, anchor clips, etc 共Fig 8兲 • The lack of end dams or sealed laps is a common flaw, with prodigious water leakage problems as a result • Incorrectly installed flashing at the backup wall For example, a lack of termination bar to mechanically fasten the flashing can allow it to slough down over time 206 JAI • STP 1512 ON MASONRY FIG 7—This wall has many inherent defects with the flashing and cavity wall drainage • Materials can change their behavior over time A common example is the self-adhering flashings consisting of a rubberized asphalt-based coating adhered to a polymer backup sheet Some products can flow in higher heat, potentially weakening the flashing performance Other products, such as plastic-based flashings, can embrittle, eventually crack, and split FIG 8—Shelf angle without provisions for movement and drainage PASHINA AND TALAFOUS, doi:10.1520/JAI102727 207 FIG 9—Cracked stone panel at horizontal joint Note the lack of weeps in the joint • Flashing is vulnerable to tears and punctures during construction Haphazard construction practices can cause • Puncture of the flashing when mechanical fasteners are installed such as for wall ties or window installations, but the fastener entry point is then left unsealed • Handling of the masonry materials being installed or careless handling of tools can cut or tear the flashing • Displacement or damage by work of other trades • Provision for drainage is necessary, but not always provided See the following, for example: • Lack of a water exit path, such as weeps • In a previously discussed example, the top joint of the horizontal shelf angle leg was sealed over with sealant Merely cutting away the sealant may greatly improve wall drainage • Another common example is the situation with masonry walls where the shelf angles and lintels are known to be improperly flashed, but the repair scope does not entail removing the masonry to expose the shelf angle/lintel in order to reflash Cutting holes in mortar head joints in an attempt to then insert weeps can damage the existing flashing and shelf angle/lintel Sometimes it may be better to nothing • Mortar droppings clogging the cavity is a well-documented problem Manufacturers have provided many devices to assist contractors, and the knowledge base has been improved, but the large inventory of older buildings with this condition will continue to provide problems for designers to repair 共Figs 9–11兲 • In many older barrier style walls, the primary seal between adjoining constructions is flexible sealant This system has a relatively shorter life expectancy than flashing and is susceptible to localized failures 208 JAI • STP 1512 ON MASONRY FIG 10—Granite panel with concealed spalling Incompatibility of Building Components Much can be learned and observed about actual construction and design practices by filling the role of a third party inspector during new construction We recently experienced this on a newly constructed school building The owner was a sophisticated buyer with considerable experience on many new buildings In fact, he had published his own design guidelines for the design team to meet The project in question was high end brick masonry cavity wall construction It had a in air cavity, air and water barrier, reinforced FIG 11—Spalled stone corner reveals corroded support PASHINA AND TALAFOUS, doi:10.1520/JAI102727 209 FIG 12—Example of surface coating entrapping water beneath the coating concrete masonry backup wall construction, a dual asphaltic copper flashing system at the windows, and detailed instructions 共written and drawn兲 on how to fold and fabricate end dams and the use of custom fabricated stainless steel pan flashings at all openings During flashing installation around the first window opening, knowledgeable personnel were providing inspection services The design team was informed of an incompatibility that existed between the concealed urethane based flexible sealants to be used around the windows and adjoining some of the flashing mastic The owner was quite fortunate that his entire flashing system was not yet installed, avoiding a sealant reversion problem later on Although special knowledge was needed to advert this potential disaster, common sense during the design phase could have prevented the problem from reaching the field by checking all materials for compatibility prior to issuing the construction documents for bid Some other common examples of incompatibility of building materials include: • Coatings that reduce the movement of water vapor through the wall system, essentially becoming a vapor retarder on the masonry surface 共Fig 12兲 • Architectural patching materials used on stone or terra-cotta but with substantially different expansion-contraction properties than the natural material The failed patch material then spalls or creates “blowouts” 共Fig 13兲 Permeability issues also can arise between the repair material and remaining masonry Common sense dictates that the consideration of materials includes both individual performance and compatibility with other materials Repairs are especially challenging since compatibility with existing and dated materials must be considered 210 JAI • STP 1512 ON MASONRY FIG 13—Stone patching material has weathered poorly and is incompatible with parent brownstone Lack of Provision for Movement of the Masonry Cracked masonry facades are another common problem A few years following construction, many buildings experience visible cracking distress, usually at predictable locations, such as the following: • At building corners, where opposing movements of the building frame and masonry veneer results in cracks This problem is recurrent with brick veneers but can just as easily occur with stone and terra-cotta • Propagating from wall openings, such as corners of windows and doors Once again, misunderstanding or failing to consider expected masonry movements results in cracking • Cracking within the general masonry field, where movement joints are far apart or incorrectly sized Many joints are built 3/8 in wide to match typical brick mortar joints, but this joint opening width may be inadequate, depending on the joint spacing, building movement, etc • Non-functioning movement joints, where the joint outwardly appears to be functional, but is constructed to prevent full movement These joints are often a thin sealant over a mortar-filled head or bed joint At first glance, a building may appear to have an adequate number of movement joints, but further investigation should always be done to verify that wall joints actually allow for movement 共Fig 14兲 • Mortar droppings can bridge an intended movement joint, allowing locations of concentrated stress • Previous attempts to install additional joints may not have been effective if, for instance, joints not fully extend through the masonry PASHINA AND TALAFOUS, doi:10.1520/JAI102727 211 FIG 14—Toothing brick at a building corner where the original joint construction was ineffective The placement of movement-capable joints both affects and is affected by building aesthetics Designers and owners may strive for a clean appearance, with fields of masonry divided the fewest number of joints Where a balance of performance versus aesthetics is not attained, function over form will always win out and result in unsightly cracking It is our opinion that a properly designed repair anticipates the movement of the masonry, appearance of the movement joints, and cost For example, a large structure with rough cut limestone block veneer over common brick without a cavity 共barrier wall兲 was recently repaired Portions of the facility contained towers, which were an important visual feature Being tall, narrow, and fully exposed to weather, the towers eventually underwent extensive cracking These cracks tended to be vertical and near the outside building corners To prevent repeat cracking, it was suggested that new vertical expansion joints be saw cut through the limestone veneer and backup construction However, after considering the need to allow for future veneer movement compared to a perceived change in the wall’s appearance, the owner preferred to forgo adding any new movement joints and accepted increased maintenance costs for correction of anticipated redevelopment of the cracks in upcoming years Common bond brick masonry construction is another example where allowing adequate movement is problematic Many older buildings were built with barrier wall brick masonry construction, where the exterior brick veneer was laid in common bond and integrally tied every sixth or seventh course to backup wall with header courses, which was usually clay tile or concrete masonry This type of wall was relatively robust and performed reasonably well for the building owner As the building aged, brick expansion, shrinkage or creep of the concrete building frame, and seasonal expansion and contraction tended to create numerous vertical cracks from constraint of the brick masonry In this construction, the differing movement characteristics of brick, clay tile, or con- 212 JAI • STP 1512 ON MASONRY FIG 15—Corner restraint at Carrara marble panel has a repair that has also failed crete masonry and the building frame inevitably led to cracking However, in designing the repairs, we found a situation where the inherent nature of the wall construction prevented adding movement joints that could be effective everywhere Our repair approach was to balance what could be consistently done to allow movement versus what could not be changed with the building construction 共Fig 15兲 In most situations, the masonry was repaired, movement joints added to the brick veneer at building corners and other areas with the largest expected movements, and the remainder of the wall left “as-is” 共after replacing cracked brick units and mortar joints兲 Poor Workmanship of a Masonry Facade A residential high-rise was scheduled for repair in the mid-2000s This 23-story tower was typical of early 1970s construction, a brick veneer with a narrow PASHINA AND TALAFOUS, doi:10.1520/JAI102727 213 FIG 16—Missing anchor at shelf angle drainage cavity The brick veneer was supported with painted steel shelf angles at every floor line As the building aged, the owner realized the need to perform maintenance on the exterior facade, and a repair program was designed, which included repointing isolated areas of masonry, resealing wall joints, and widening expansion joints, which had narrowed due to brick expansion Other than the minor distress seen on the exterior, the building outwardly appeared to be performing adequately During the repair, we were retained by the owner to make periodic inspections to verify the contractor’s compliance with the project requirements Beginning with the first swing stage drop, mortar joints were cut, and isolated cracked brick began to be removed at building corners Soon, some of the shelf angle anchor holes were exposed—with no anchor bolts! Further investigation was made on randomly selected shelf angles, and it was found that over 25 % of the shelf angles had: • Missing anchors 共Fig 16兲 • Anchors protruding through a drilled hole but no washer or nut • Shelf angles with drilled anchor holes but only a grossly undersized 共3/8 in diameter兲 anchor, nut, and washer • Flame-cut holes, some open to the top of the angle vertical leg, with haphazard engagement of the anchor nut • Inadequate shims consisting of a stack of washers at the top of the angles 共Fig 17兲 214 JAI • STP 1512 ON MASONRY FIG 17—The shelf angle is shimmed with haphazardly placed washers • Shelf angles displaced upward by the expanded masonry below, displacing the anchor wedge out of the slot Although it was not the case with this project, we have found incorrectly sized shelf angles to be a common condition in our studies of other buildings These global conditions were surprising, even more so when considering no significant movement of the facade had been observed Some wall segments had a slightly convex vertical curve between shelf angles but not necessarily exceeding “typical” construction tolerances How and why was the building constructed in this manner? These errors in workmanship throughout the building were certainly not random events We came to the conclusion that qualified inspection was not performed and careless or untrained workmanship was the likely cause for the observed problems Our initial inspection and follow-up investigation found serious defects and potential safety hazards The owner immediately agreed with the need to address these conditions, and the resultant repairs to the shelf angles 共by change order兲 more than doubled the project cost We finished the project still scratching our heads in amazement at the variety of careless defects we had found! Many of the perceived restraints on the design and construction phases such as time, budget, level of craftsmanship, and material costs and should affect the project However, these constraints must be balanced against the overall performance of the masonry PASHINA AND TALAFOUS, doi:10.1520/JAI102727 215 Conclusions Masonry is constructed with a wide variety of materials It has more components than many other types of construction, so its performance is more dependent on both workmanship and materials When repairs to masonry are required, a common sense approach helps Major considerations for developing a successful repair project include • Planning and communication are key • Initial consultation with the building owner to establish the owner’s needs, desires, and expectations • Performing a thorough pre-design investigation of both good and bad areas—known or documented problems as well as areas conceived to be functioning as intended 共for comparison兲 • Making sure the owner’s budget matches the anticipated work scope and his expectations • Making adjustments or compromises where appropriate and reevaluating as the project progresses • If cash flow is a problem, can the repairs be extended over multiple years and phases to meet the owner’s budget constraints? • Is a shorter life expectancy repair approach sufficient to meet the building’s immediate concerns and owner’s budget and desires? Can the extent of repair be limited to the most critical areas? Can some of the future anticipated needs be included now? Is the selection of repair materials and techniques appropriate for the work? Critically assessing these questions in advance can result in lower cost for repairs • Providing the owner with choices of repair approaches with varying life expectancies, initial costs, and accompanying maintenance costs Bring the owner into the discussion and let him examine their options from an informed viewpoint The repair consultant needs to thoroughly communicate the differences between the approaches, not just the work scope and initial construction costs, but anticipated future costs as a consequence of choosing one approach over another • Selecting materials and techniques that are appropriate for the building and repair approach, keeping in mind not only the performance of each product individually but also how it will interact with adjacent materials that are to remain or are new to the building • Providing the repair contractor thorough yet concise and understandable repair documents using proven materials and techniques • Choosing design professionals and other qualified personnel with sufficient repair experience and familiarity with the type of construction, project size, and complexity of the repair project Masonry repair is a specialty field, and most new construction designers not have the knowledge to undertake such projects • The design professional should remain involved in the repair during construction activities • The contractor should be one who specializes in masonry repair, not new construction The skill set of the masons is vastly different between the two types of contractors 216 JAI • STP 1512 ON MASONRY • Finally, be prepared for and expect changes due to hidden conditions or other unknowns It is the nature of repair Communicate this with the owner at the beginning and insist that a contingency be budgeted It will make the entire process more pleasant and demonstrate your foresight