1、Designation: C1496 11C1496 18Standard Guide forAssessment and Maintenance of Exterior Dimension StoneMasonry Walls and Facades1This standard is issued under the fixed designation C1496; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide outlines how to visually assess exterior stone masonry walls and facades to determine their
3、general condition.Examining key features of the construction can help identify and diagnose problems which require repairs or corrective action.Such an examination can expose conditions which may be addressed with maintenance and minor repairs, or may require expertassistance. This guide is not inte
4、nded to be used for buildings requiring major exterior rehabilitation or structural repairs.1.1.1 This guide applies to walls of solid stone or dimension stone used as a cladding. Stone cladding is typically connectedto a backup material with a variety of anchoring methods, including traditional han
5、d-set masonry anchors such as straps, dowels,cramps, hook-and-eyes, dove-tails, wire ties, and the like. Joints between stones in these types of buildings are usually filled withmortar or sealant. Sealant-filled joints are usually designed to accommodate structural and thermal movements.1.2 This gui
6、de specifically excludes dimension stone used in interior building surfaces, flooring or paving, slate dimension stoneused as roofing. Though they share some similar assessment and maintenance concerns, thin stone (less than 2 in. nominalthickness) exterior cladding, and stone cladding attached to m
7、etal flames are also excluded due to their unique designcharacteristics and performance requirements. Although procedures and cautions listed herein may apply to walls and facadescontaining semi-dimension, or partially sized, stone in the form of split-face, or rubble and to stone-facade concrete pa
8、nels, theguide is not specifically directed to such stone use. It does not address removal of small-area stains.1.3 This guide offers an organized collection of information or a series of options and does not recommend a specific courseof action. This document cannot replace education or experience
9、and should be used in conjunction with professional judgment.the judgment of stone restoration design consultants. Not all aspects of this guide may be applicable in all circumstances. ThisASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given pro
10、fessional stoneconsultants service must be judged, nor should this document be applied without consideration of a projects many unique aspects.The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensusprocess.1.4 The values stated in i
11、nch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It
12、 is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsib
13、ilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestabl
14、ished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.1 This guide is under the jurisdiction ofASTM Committee C18 on Dimension Stone and is the direct responsibi
15、lity of Subcommittee C18.07 on Environmental Properties,Behavior, and Cleaning.Current edition approved Oct. 1, 2011Nov. 1, 2018. Published November 20011November 20018. Originally approved in 2001. Last previous edition approved in20092011 as C149609.C149611. DOI: 10.1520/C1496-11.10.1520/C1496-18.
16、This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior edi
17、tions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:2C119
18、Terminology Relating to Dimension StoneC1515 Guide for Cleaning of Exterior Dimension Stone, Vertical And Horizontal Surfaces, New or ExistingE1971 Guide for Stewardship for the Cleaning of Commercial and Institutional Buildings3. Terminology3.1 Terms used in this guide are defined in Terminology C1
19、19.3.2 Definitions of Terms Specific to This Standard:3.2.1 crack monitorany of the several two-part devices that can be attached to stone masonry in such a way that they can spancracks in order to periodically measure changes in crack width thereby indicating movement.3.2.2 dutchmanrepair used to p
20、atch stone masonry with a section of new stone. The damaged area within a particular stoneelement is removed. The remaining void is trimmed to a regular shape.Anew piece of stone, or “dutchman,” is cut from matchingstone cut slightly smaller than the area to be filled. It is installed using dowels o
21、r some other mechanical attachment, then adhered,or mortared into place.3.2.3 exfoliationdeterioration or loss of certain types of stone in the form of flakes, scales, and layers.3.2.4 professional assistancequalified stone consultantindependent opinions and recommendations provided by personshaving
22、 expertise in the assessment and repair of stone masonry. Such professionals These may include independent consultantssuch as architects, engineers, material scientists such as mineralogist or geologists, or stone masonry contractors.3.2.5 thickstones with a nominal bed-depth of 2 in. (5 cm) or more
23、.4. Significance and Use4.1 This guide attempts to provide information to assist building owners and managers with limited knowledge of stoneconstruction to recognize basic problems with performance of facades, and to keep them in good condition through periodicinspections and maintenance. Increased
24、 awareness of the behavior of stone masonry facades and associated materials can reducemaintenance and replacement costs by addressing problems and deterioration early.4.2 The objective of all maintenance should be to limit deterioration through early intervention.4.3 When it appears damage to stone
25、 support elements has occurred, professionals a qualified stone consultant should beconsultedemployed to evaluate the support conditions, as well as recommend methods to restore the buildings integrity andpreserve public safety.5. Introduction5.1 An effective maintenance program for exterior stone m
26、asonry should incorporate preventive maintenance among its keyelements. Early attention to problems, and simple measures to remedy them, will often avoid costly renovation later. This guideis intended to help interested personnel locate such problem areas, better understand potential causes of stone
27、 deterioration, andidentify appropriate corrective measures for the observed deficiencies.5.2 Maintenance supervisors should understand how their building is constructed to apply this guide and better maintain theirbuildings. Employing a professional qualified stone consultant to assist them in inte
28、rpreting pertinent drawings and documents, andinitially inspecting conditions should help them become effective observers of stone performance.5.3 This guide lists many typical problems that can affect stone masonry, facades. It describes likely causes, and discussescommon repair methods. All initia
29、l attempts at repairs should be done under the observation of a professional qualified stoneconsultant to ensure the use of proper materials and techniques.5.4 Personnel responsible for stone facade maintenance should be familiar with the systems used in the construction of theirbuildings on at leas
30、t an elementary level. Prior to inspections, they should be briefed by personnel knowledgeable about thebuilding and its construction, particularly the stone wall system. This background should help in determining when the engagementof a professional qualified stone consultant should be considered.5
31、.5 In cases where the building or its facade has cultural, civic, historic, or architectural significance, consultation with aspecialist is recommended.5.6 When assessing the condition of exterior dimension stone, and particularly any problems requiring action, the appropriatecleaning or repair meth
32、ods should promote eco-efficiency, avoid any adverse impacts on humans present or involved, avoid any2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Do
33、cument Summary page on the ASTM website.C1496 182adverse impacts on the building structure, and reduce stress on the environment. See Guide E1971. Choices must be made oncleaning products and processes, and building repair materials and method.5.6.1 Certain pertinent questions should be considered h
34、ere: (1) how is the building used? (2) what type of dimension stone andwhat finish was used? (3) is the dimension stone load-bearing or is the load carried by other materials such as steel or concrete?(4) are there any issues relating to building age or architecture? (5) what criteria or measures wi
35、ll be used to evaluate the qualityof cleaning and repairs?6. Guidelines for Inspections6.1 Schedule InspectionsSchedule and perform semi-annual inspections of stone wall elements. Inspect all elevations of thebuilding.Awalk-around visual survey with a camera and binoculars should be a minimum proced
36、ure. Use adjacent buildings roofsand windows to gain same-level access, to examine building facades and associated elements. Use building windows and set-backswhere possible for additional vantage points. If the available access is not sufficient to perform the inspections, then considermethods, as
37、outlined in 6.3. Photograph any observed distress or problem areas for later reference in determining appropriaterepairs.6.2 Condition Documentation/MonitoringKeep accurate and cumulative records of inspection findings. Buildings constructedof thick dimension stone with mortar or sealant-filled join
38、ts react slowly to environmental forces. Knowledge of the timing of aconditions onset and understanding its progress aid in assessing the distressed condition. Monitor critical or deteriorated areasbetween scheduled inspections. Use measurements or crack monitors to measure changes in cracks, increa
39、sing lippage betweenstones (stones projecting or retreating in plane from the adjacent stones), or other changes and displacements in stone position.Well-kept records will aid in the diagnosis of the specific causes of the conditions observed, should more experienced professionalsa qualified stone c
40、onsultant be required.6.3 Tall BuildingsInspections of buildings with heights that exceed those readily observable with binoculars, or with limitedvantage points require more detailed planning. It will be necessary to view representative areas of the facades from suspended orfixed scaffolding, mobil
41、e work platforms, or personnel lifts to adequately observe existing conditions.7. Procedure for Evaluation of Stone Conditions7.1 At a minimum, the following procedure should be used as a guide to decide an appropriate course of action for observeddeficiencies as part of an inspection and maintenanc
42、e program for stone masonry facades.7.1.1 Identify and document the defects.7.1.2 Note the extent of the defects, patterns or concentrations of distress.7.1.3 Postulate the likely causes.7.1.4 Perform necessary maintenance or obtain assistance with repairs:7.1.4.1 If the condition is stable and does
43、 not appear to be progressive, perform appropriate maintenance, and simple ortemporary repairs.7.1.4.2 If the cause is not apparent, and the condition appears stable and not progressive, monitor the condition and consult withprofessionals a qualified stone consultant to determine the cause and appro
44、priate repairs.7.1.4.3 If the observed conditions are considered dangerous or progressive, obtain professional assistance assistance from aqualified stone consultant immediately.8. Maintenance8.1 Routine MaintenanceMany problems can begin or worsen due to neglect of routine maintenance. Stone masonr
45、y itself,when used in an exterior application, requires periodic joint repairs, such as sealant replacement, tuck pointing, and cleaning. Stonefacade components can also be affected by a lack of maintenance of other building systems, such as roofs, parapets, windows, andflashing.8.2 CleaningRegular
46、cleaning is also critical to the long term durability of natural stone facades, as well as their appearance.Cleaning methods should be selected that do not damage the stone. Cleaning methods and materials should be first tested, fromthe least to the most aggressive, to determine the mildest treatmen
47、t that provides satisfactory results. Prior to implementing acleaning technique building-wide, test areas should be cleaned using the proposed methods. The areas should be evaluated for aminimum period of six weeks to assess the results. Improper selection of cleaning chemicals and procedures will p
48、roduce unsightlyand irreversible damage to the appearance, and potentially the structural integrity, of the stone facade components. Refer to GuideC1515 for procedures for cleaning exterior stone.9. Areas of Focus for Inspection9.1 Moisture or Water StainingLook for signs of moisture on interior and
49、 exterior surfaces, as well as throughout the stonewall system. Water penetration can lead not only to deterioration of interior finishes, but also to stone and joint material degradationand corrosion of anchor system components if the water is trapped behind or within the wall or facade system for prolongedC1496 183periods. Water absorbed into stone and joint materials can cause dimensional changes, potentially reducing clearances and creatingstress concentrations. Trapped water can freeze and expand, causing the stone to weaken, and eventually spall or crack. J
