MSJC TAC Responses 2013ef.engr.utk.edu/efp/msjc/TAC_Review_Comments-MSJC-2… · Web view2013. 5....

2013 MSJC Committee Responses to the 2013 MSJC TAC Comments onBuilding Code Requirements and Specification for Masonry Structures & Commentaries

No. Section or Article #

Page Line Classification

Comment Sub 2013 Committee Response Holdover (Y)

2016 Committee Response

C or S (P,S,E,L)

5 P General: A TAC comment from the 2011 cycle (TAC Comment 7) suggested to the Committee that Code chapters should be organized in a logical and consistent manner so that a user does not need to ‘relearn’ where provisions are located when jumping between (say) ASD and SD. The recently updated Committee response to this previous TAC comment is that work on this is ongoing with the hopes of finishing this effort in the next cycle. Taken by itself, this presents little problem, however, when coupled with the major reorganization of the Code introduced in this cycle a significant issue does arise. Effectively the Committee is asking users to learn a new Code in 2013, with explicit plans to do so again in the next cycle. While never pleasant, most recognize the need for such reorganization every couple decades to maintain a user-friendly document. By the Committee’s own acknowledgement, however, this reorganization is only partially complete. To the extent possible, the committee is requested to address this issue.

GR The Committee agrees that further adjustments could be made for greater consistency between chapters such as between ASD and SD or SD and AAC chapters. The Committee also agrees that certain provisions could be moved from design chapters in Part 2 into Part 1. The Committee has proposed changes in an attempt to address the commenter’s intent. Those changes were balloted as part of Main Ballot 2013-07-G-021. Persuasive negatives were found. The committee will continue to work on this. If possible the comments from Bennett and Jaffe will be incorporated and re-balloted at subcommittee and then at Main 08.

Update from Chair: Proposed changes received persuasive negatives at subcommittee ballot prior to Main 08. No reballot on Main 08.

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As examples of needed reorganization, the committee should group common design provisions together rather than in separate locations (e.g., beams). Another need is to organize provisions similarly within chapters covering different engineering design methods (e.g., ASD and SD provisions).

6 S A comment submitted during the last cycle asked that shear friction provisions be considered. This was not completed in this cycle, which is unfortunate. The response indicates that this was worked on, but not completed. If possible, consider working on this now before the Public Comment period. It would be nice to get it done.

FAS The subcommittee has had discussions on this item but due to time constraints and other higher priority items, no consensus at the subcommittee level has been reached.

The Committee prioritized the important Primary comments as well as numerous editorial comments assigned to the FAS Subcommittee for consideration, ahead of this item and as such the Committee will carry it forward to the next cycle for consideration.

Y

18 1.1 C-1 50 P Move first paragraph on the commentary side down to parallel section 1.1.2 of the code side. This paragraph reads like commentary to 1.1.2.

GR To be balloted on Main 08.

Update from Chair: The subcommittee was unable to prepare a ballot for Main 08. Item will continue as new business.

Y

19 1.1 C-1 55-65

S Seems an odd place for structural integrity commentary. No code has been presented yet. Consider creating nominal provisions for integrity and placing in the code. Otherwise, find a more appropriate location.

GR The Committee prioritized the important Primary comments as well as numerous editorial comments assigned to the General Requirements Subcommittee for consideration ahead of this Secondary item and accordingly, the Committee will carry

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it forward to the next cycle for consideration.

21 1.2.2 C-2 12 S Regarding the list of code-required drawing items shown on the project drawings, I know that the quality assurance program is typically laid out within the project specifications, but would it be beneficial to list the Level (A, B, or C) of the required quality assurance program on the drawings as well?

GR The Committee prioritized the important Primary comments as well as numerous editorial comments assigned to the General Requirements Subcommittee for consideration ahead of this Secondary item and accordingly, the Committee will carry it forward to the next cycle for consideration.

Y

27 1.2.1 C-2 50 S The following Commentary sentence is unrelated to the discussion. Delete or relocate.“A Commentary on TMS 602/ACI 530.1/ASCE 6 follows the Specification.”


Y

29 Commentary – 1.2.2

C-2 60 S Change last sentence to read “While load transfer usually involves non-structural masonry…frames, to structural and non-structural masonry should also…”


Y

32 Fig CC-1.2-1

C-3 66 S For the figure on veneer wythe wall anchorage details, not to be too self-promoting of masonry, but should we also show a detail for veneer over masonry backup? This could help drive home the idea that

GR The Committee prioritized the important Primary comments as well as numerous editorial comments assigned to the General Requirements Subcommittee for consideration ahead of this Secondary item and

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accommodation for differential movement also needs to occur between masonry elements, and not just between masonry/steel or masonry/concrete.

accordingly, the Committee will carry it forward to the next cycle for consideration.

40 2.1 C-7 6 S For the list of notations, has any consideration ever been given to listing the code section where the variable is used, similar to the format of the notation section in ACI 318?


Y

50 2.2 P Delete the following definitions from the Code and Spec outright:

- Column- Foundation pier- Pier- Wall

And any other configuration-dependent definition. These definitions do more harm than good. According to the Committee responses to TAC comment from the past two cycles, the Committee recognizes the flaws in these definitions and has been attempting to fix them for years. Don’t fix them, delete them. Because of the absolute nature of these definitions they override engineering judgment and are therefore unsafe. I have lost count of how many times I’ve spoken with engineers that intentionally make their columns a little longer in one direction so they

GR The committee agrees that definitions and the use of geometric requirements in the definitions can be confusing and restrictive. The Committee, however, feels that acceptable definitions provide value to the user and has crafted revised definitions for ballot. New definitions were balloted at subcommittee and an item addressing several items except for columns and piers was balloted as part of Main Ballot 2013-07. (Item 07-G-005a) Persuasive negatives were found .Committee intends to continue work on this item.

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do not need to comply with the prescriptive column detailing requirements.

51 Code – 2.2

C-14 5 S Delete “structural” before “support”. GR The Committee prioritized the important Primary comments as well as numerous editorial comments assigned to the General Requirements Subcommittee for consideration ahead of this Secondary item and accordingly, the Committee will carry it forward to the next cycle for consideration.

Y

53 Code – 2.2

C-14 35 S Add “structurally” before attached in definition for Backing.


Y

61 2.2 C-16 11 and 15

P The definitions and terms for ‘cavity’ and ‘collar’ and not used consistently throughout the Code and Spec. The commentary differentiates between these two spaces by their size. The composite/non-composite provisions are slightly different yet. The veneer provisions use ‘cavity’ when the backing is non-masonry (as opposed to two wythes as defined here). The Spec requires (not permits) collar joints to be filled with mortar when of a certain size.Be consistent throughout.

GR Committee Response: The committee agrees that the definitions and use of the terms ‘cavity’ and ‘collar’ are at times unclear and overlapping and that greater clarity is required. Changes to the definitions were balloted as part of Main Ballot 2013-07. Persuasive negatives were found. The committee will continue working on this item. Also see response to TAC Comment 51.

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62 2.2 C-16 17 P Delete “isolated”. Every engineer understands what a column is. Isolated could have other meanings as being not attached to anything including top and bottom. Does the code address attached columns similar to boundary elements in RC shear walls?

GR The committee disagrees that the concept of isolated is understood by every engineer and has concern that deleting the term literally or conceptually would lead to greater confusion and possible mis-application of the Code than would better definitions for the members. Of particular concern is the case of slender portions of masonry within walls that may satisfy the geometric portions of the definitions while not being ‘isolated’ – research among crafters of the Code indicates strong consensus that masonry within a wall be designed under the wall provisions and only when the masonry is isolated should it be designed under the provisions for a column or a pier.

Changes were balloted to clarify the members and their definitions as part of Main Ballot 2013-07. Persuasive negatives were found. The committee will continue working on this item.

Y

68 2.2 C-17 27 E Revise as follows, waiting for all losses to occur could be time consuming:Effective prestress — Stress remaining in prestressing tendons after all losses have occurred.

Prestress

Balloted on 07-P-006. Changes proposed consistent with TAC comment. Received one negative that was found persuasive. After further discussion, the committee recommends maintaining the current language and revisiting this item next cycle when PTI finalizes their definitions.

Y

71 Code – 2.2

C-19 10 P Change definition for Load, Service to “Load specified by the legally adopted building code when the structure is in service.” to match the

GR The Committee agrees that the definition of Service Load could be improved. Changes were balloted at subcommittee to revise the definition

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commentary in 8.1.1. for Service Load and to create definitions for Nominal Load and Factored Load where a persuasive negative was received. The item was reworked and will be balloted as part of Main Ballot 2013-08, if the subcommittee ballot does not receive persuasive negatives.

Chair Update: Persuasive negatives received at subcommittee. No ballot on Main 08.

Work will continue next cycle.

72 2.2 C-19 11 P The Code uses the term ‘service load’ both incorrectly and inconsistently, sometimes in the context of serviceability and sometimes for nominal design loads. The correct term here is ‘nominal load’, which is the term used in ASCE 7 and the building codes. Search and replace correctly throughout.

GR The Committee agrees that the use of Service Load is neither consistent nor correct. Changes were balloted at subcommittee to revise the use of Service Load to Nominal Load where appropriate and that ballot received a persuasive negative. The item was reworked and balloted as part of Main Ballot 2013-08 if persuasive negatives are not received at subcommittee. See also item 71Chair Update: Persuasive negatives received at subcommittee. No ballot on Main 08.

Y

83 Chapter 2

Chapter 8

C-23 C-112

13 4

E Chapter 2 (definitions) states tensile resistance of masonry exists. Chapter 8 (ASD) states tensile resistance of masonry is neglected. Improve wording to be clear on meaning.

FAS Change Section 2.2 in Ballot 07-F-018 consistent with the TAC suggestion. A persuasive negative received. Main ballot 08-F-018 addresses the negative and the TAC comment. Negative was received. Item does not move into the working draft.

Work will continue next cycle.

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89 3.1.2 C-26 5 S The single largest performance problem of contemporary masonry construction centers on masonry veneers. Every investigation following every natural disaster has documented veneer failures; and in virtually every one of these cases the reports cite the lack of ties; the improper use of ties; ties bent up and not engaging the veneer; fasteners installed into sheathing and not studs; nails used as ties; and on and on. The problem isn’t with the provisions of the MSJC, but rather their execution in the field. The performance of masonry veneers would significantly improve with a very small amount of inspection. Require the equivalent of a Level B QA for the installation of masonry veneers in Risk Category II, III, and IV structures (possibly with an exception for one- and two-family construction).

CR This item was balloted at Main 07-C-033 and received several negative votes with 1 found persuasive. The guidance of inspection requirements may extend beyond veneer which requires additional consideration. This item will be considered as new business in the next cycle.

Y

95 Tables 3.1.2 & 3.1.3

C-28 to 30

1-40 S I understand that it is the responsibility of the designer to lay out the expectations for the QA program in the project documents. However, the term “periodic” when describing inspection frequency is very open-ended. Should the code provide some guidance, if not within the code table then at least in the commentary, on what the maximum and minimum reasonable expectations are for periodic inspection? It could be defined as a percentage of time onsite or review

CR The CR Subcommittee understands the quagmire presented by the TAC Comment. The term “Periodic Special Inspection” appeared in the 1973 Uniform Building Code (Section 305 (c)) and since then, the Uniform Building Code and the International Building Code has not quantified how much periodic special inspection is appropriate.

Quantifying the appropriate amount of period inspection is complex since it will vary with the type of building and building use, and other possible factors. In addition, the designer may

Y

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of a certain percentage of elements. require a level of inspection confidence that may vary between designers and also be contingent on the contractor performing the installation.

The CR Subcommittee will work on this item in the next cycle with a goal of quantifying how much is appropriate for periodic inspection.

100

3.2.2.1 C-32 50 S Add additional commentary discussion to clarify that ‘embedded’ and ‘encased’ materials are two different details and that these limits do not apply to conduits, pipes, and sleeves encased in masonry.


Y

115

4.3.1 C-41 55 S Delete the following commentary statement. It is unclear what the user is being instructed to do or what this minimum net section would be used for.The designer may choose to use the minimum thickness of the face shells of the units as the minimum net section.


Y

116

4.3.1 C-41 59 S Revise as follows. A few conditions are missing.For masonry of hollow, ungrouted units laid in face shell mortar bedding, the minimum cross-sectional area in both…


Y

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117

4.3.1 C-41 66 S Revise as follows:Since the elastic properties of the materials used in members designed for composite action may differ, equal strains produce different levels of stresses in the components. To compute these stresses, a convenienttransformed section…


Y

120

4.3.4 C-43 4 S Change the phrase “The bearing area, Abr, for concentrated loads shall not exceed the following:” to “The bearing area, Abr, shall equal the lesser of:”. Rationale is that Abr is something that is calculated per the code for analysis purposes, not something that is specified by the designer with “not to exceed” values.

F&S The Committee balloted a change consistent (but not exactly the wording proposed in the TAC comment) with the TAC Comment on 07-Q-16. That ballot item received three negatives that are unresolved. Item will continue to be discussed next cycle.

Y

121

Commentary – 4.4

C-44 41 S Does this first sentence refer to veneer only or all masonry? If veneer only, it should say so. Otherwise, change “curtain” to “infill.”


Y

122

4.4 C-44 70 S What does ‘embedded’ mean in this context? I’ve never heard of beam supporting masonry as being ‘embedded’.

GR The Committee prioritized the important Primary comments as well as numerous editorial comments assigned to the General Requirements Subcommittee for consideration ahead of this Secondary item and accordingly, the Committee will carry it forward to the next cycle for

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consideration.

123

4.4 C-44 70 S Revise as:Beams or trusses supporting masonry walls are essentially embedded, and their deflections are required to should be limited…


Y

130

5.1.3.2 C-51 11 S For clarity, revise as follows:5.1.3.2 For walls not laid in running bond, concentrated loads shall meet the requirements of Section 5.1.3.1 and shall not be distributed across head joints.


Y

131

5.1.3 C-51 45 S Revise as follows to clarify for multi-story construction:Arora (1988) suggests that a concentrated load can be distributed at a 2:1 slope, terminating at half the wall height, where the wall height is from the point of application of the load to the foundation, not to be taken larger than the story height.


Y

137

5.2.1.1.1

C-53 10 S This section addresses the span length of beams not built integrally with the supports – what about beams built integrally with supports?

FAS Beams with fixed or partially fixed supports can be conservatively dealt with using the current provisions. A ballot will be submitted to Main 08 to add commentary.Chair Update – This item received a persuasive negative at Subcommittee

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(ballot 08-F-43) so it didn’t get balloted on Main 08. It will be considered in the next cycle.

146

5.2.2 C-55 50 S There was recently a paper in TMS Journal related to deep beams by Fonseca, Mathew, and Bennett. If appropriate, reference here.

FAS The Committee prioritized the important Primary comments as well as numerous editorial comments assigned to FAS Subcommittee for consideration, ahead of this Secondary item and as such the Committee will carry it forward to the next cycle for consideration.

Y

148

5.2.2.4 C-56 11 P These provisions make masonry beams unbuildable in many cases where shear reinforcement is required.

The last sentence of item (b) would require two legged stirrups (or steel on both faces) for all beams wider than 8 in. This is very difficult to do in masonry due to constructability issue, congestion, etc. But item (c) is even more ridiculous. It requires the shear steel (admittedly only when it is required) at a maximum spacing of 1/5 the total deep depth. That means, for typical concrete masonry, with cores every 8 inches on center, all beams less than 40 inches deep would require shear reinforcing (if it is required) at a spacing of less than our 8 inch module.

Because these restrictions are so excessive, it encourages designers to use of deep beams without shear reinforcement. That is counter to

FAS The provisions mentioned in this TAC comment do require significant amounts of shear reinforcing, but these provisions are based on the research cited in commentary. However it should be noted that the shear reinforcing provisions only apply to deep beams (Ones whose depths dv are at least ½ the effective span) and do not have sufficient shear strength to resist the applied loads with the masonry alone. This is not very common.

The Committee prioritized other important Primary comments, assigned to the FAS Subcommittee for consideration, ahead of this item and as such, the Committee will carry it forward for future consideration.

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what we want (that is, these provisions encourage the designer to make the beam deeper to give us more masonry shear resistance, so we don’t have to include shear steel – it just makes no sense, and it makes the beam “deeper”).

I think these provisions need a major overhaul to be reasonable and practical. They should not penalize a design that adds strength and ductility through the use of shear reinforcement.

154

5.3.1.4 C-57 15 P The requirements for an included angle of not more than 135 degrees” in this section has been causing confusion:

(c) Lateral ties shall be arranged so that every corner and alternate longitudinal bar shall have lateral support provided by the corner of a lateral tie with an included angle of not more than 135 degrees.

Please consider clarifying this section to make it clear the difference between the “included angle” for ties and a standard hook. That is, we want the longitudinal bars to be supported by a tie, and that tie is to be bent at that location. The angle formed by that bend is not permitted to exceed 135 degrees, so that rigidity is provided at the longitudinal bar. This requirement does not pertain to the hooks at the

R&C

The subcommittee agrees and balloted changes via subcommittee ballot. Item will be on Main 08 as item 08-R-012. Negatives received. Item does not move into the working draft.

Item will be carried over into the next cycle.

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ends of the ties.

ACI 318 has similar requirements and language. The ACI commentary includes a clarifying figure (right-hand figure). Consider adding a similar figure to our commentary.

159

6.1 C-61 15 P I would like to see consistent requirements for reinforcement in ASD and SD (and prestress and AAC as appropriate). This includes type and size of reinforcement permitted. Also whether bundled bars are permitted or not.

As a practical matter, IBC over-rides the MSJC provisions on this issue.

R&C

Several ballots in previous editions have tried to align the ASD to SD and AAC provisions relative to reinforcement requirements. These previous ballots were not successful, with a roughly 50-50 split. From previous cycles, it was determined that:

1. There is no data saying that the maximum size of bars for ASD should be limited to #9 rebar. Larger bars have been used successfully when designed using ASD procedures and there have

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been no reported failures associated with the larger bars. The consensus was that the large bars are limited by other factors and additional limits are really not needed.

2. We tried to increase the maximum bar size in Strength Design but could not find any data with larger bar sizes that could be used to confirm the strength equations are accurate enough for use with the larger bars.

The current subcommittee considered several options to address this comment and was again unable to come to resolution on this issue in the absence of any new research.

Consideration of this issue will continue in the next Code Development Cycle if new research develops.

191

7.3.2.6.1.1

C-80 30 P Unlike Section 7.3.2.6.1.2, Section 7.3.2.6.1.1 does not limit this check to in-plane seismic loads. I put myself into a straightjacket each time I attempt to comply with this provision for out-of-plane wind uplift, in-plane seismic overturning, and the myriad of other loads and load combinations for a single element. The only functional solution as written is to set Vn = 2.5

Seismic

Although this comment refers to several aspects of capacity design for shear, its key request seems to be that Code 7.3.2.6.1.1 be worded more like Code 7.3.2.6.1.2. Because capacity design is independent of loads, it would be impossible to require capacity design for in-plane seismic shear only. It is useful to insert the clarification that this is for design for in-plane forces. The Seismic

Y

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Vu and increase the thickness of the wall and/or add unnecessary bond beams.

Subcommittee has balloted a change to address this issue. The next request is for clarification of the axial load at which the in-plane flexural and shear capacities are to be evaluated. In previous discussions of this issue, the Seismic Subcommittee has generally favored using the axial force from gravity loads alone in the governing seismic loading combination (usually the 0.9D from 0.9D + 1.0E). As an item of new business, the Seismic Subcommittee will consider developing formal language for this.

192

7.3.2.6.1.1

C-80 30 P Does the shear capacity check apply to a line of resistance, or to each element within a line of resistance? Clarify.

Seismic

As currently written, the shear capacity check applies to each element (“When designing reinforced masonry shear walls . . . of the element, . . .”). The Seismic Subcommittee believes that the present language is clear, and also proper. If capacity design is applied to a line of resistance, it would be possible to have individual wall segments in that line fail in shear. This would clearly be undesirable. The current requirement is intended to ensure that the capacity of each wall segment is governed by flexure. This will then apply to the entire line as well. As an item of new business, the Seismic Subcommittee will consider whether this requirement ought to be applied to each line of shear walls rather than each shear wall.

Y

201

7.3.2.12 C-83 49 P This is confusing to refer to two different editions of ASCE 7 (two different tables from two different

Prestress Balloted on 07-P-009. Changes

proposed were consistent with TAC

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editions of ASCE 7) are referred to), particularly when neither is listed in the references at the end of the Code. Revise for clarity. Same issue on Line 60 of the commentary as well.

comment. One of three negatives was found persuasive. The prestressed subcommittee will continue to work on this item next cycle to address comments and negatives received on this item.

216

8.1.2 C-89 30 P In other sections of the Code, the user is required to use the loads from ASCE 7 when not addressed by the building code. Add a similar requirement here as well.

GR The Committee agrees that the Code should consistently refer the user to ASCE 7, as in Section 9.1.2, rather than to the building official as is done in this section. Changes were balloted as part of Main ballot 2013-07-G-019 to revise the language to be similar to the language in the strength design provisions of Chapter 9 with modifications for allowable stress design.

This ballot item received a persuasive negative and the subcommittee has re-worked the item and has brought it to Main 08 as item 08-G-019. Negatives received. Item does not move into the working draft.

Work will continue in the next cycle

Y

227

8.1.5 C-91 32 S Any technical reason that multi-wythe construction is not applicable to strength design?

FAS The committee agreed - See Ballot 07-F-021. Persuasive negative. Reballot 08-F-047. Negative received. No change made.

The item will be carried into the next cycle.

Y

232

Chapter 8

C-91 34 E Words “other than AAC or glass units” added at end of Section 8.1.5.1; ballot 05-F-014

FAS Agreed – See Ballot 07-F-021. Persuasive negative received.

Reballoted on 08-F-47 consistent with TAC suggestion –and provisions were

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moved to Chapter 5 only (Chapter 8 is ASD and does not apply to AAC)

Negative was received. Item does not move into the working draft.

Item will be carried into the next cycle for consideration.

237

Chapter 8

C-92 47 E Word “metal ties” replaced with “headers”; ballot 04-F-014

FAS Agreed – See Ballot 07-F-021. Persuasive negative received. Reballotted on 08-F-047. Negative received. No change made.


Y

238

8.1.5.2 C-92 71 S I find commentary statements such as this perplexing. If the committee does not recommend a specific detail, why is it permitted?


Y

245

8.1.7.2 C-96 29 P Equation 8-11 applies to the development of wires in tension, but there are no corresponding splicing requirements for wire. Is welding permitted, and if so, what are the requirements? The 6 inch minimum lap length cited in the Spec is inadequate for all wire diameters – being only half of what would be required for 0.25 inch diameter wire.

R&C

The subcommittee agrees. See Ballot 07-R-019 and Ballot 08-R-019. Negative was received. Item does not move into the working draft.


Y

247

8.1.7.4 C-97 14 P The embedment requirements for ASD are largely those given in ACI

R&C

The committee agrees with the comment. However, the committee

Y

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318. Similar requirements are absent for SD (Chap 9) and AAC (Chap 11). Why?

Add these reinforcement detailing requirements to Chapter 6 so that they apply to other design methods as well.

feels a comprehensive approach is required for this and other related items rather than to develop a piecemeal approach. This will be taken up as a new item of business in the next cycle.

273

8.3.1 C-113

5 S Chapter 2 has a definition for unreinforced masonry, but not for reinforced masonry. Having a definition for reinforced masonry would save repeating charging language such as this.


Y

277

8.3.4.2.1

C-114

15,

20

P I would like to see the 0.25 factor in code equations 8-21 and 8-22 changed to 0.33. This change can be supported by the research and trial designs used when recalibrating other ASD allowable stresses during the 2011 code cycle. Although this change may have been delayed during the 2013 cycle due to concerns and/or coordination issues with unreinforced and prestressed masonry provisions, I believe it could still be made this cycle if limited to reinforced masonry only (Section 8.3.4.2.1) which should not adversely affect the unreinforced and prestressed code provisions.

FAS The committee was not able to come to consensus on the value to be used for this compression stress factor. While the analysis used for the stress recalibration showed that that the 0.25 value was conservative, the compression stress does not govern often and due to time constraints and other higher priority items, this issue will continue to be discussed in the next code revision cycle.

Y

279

8.3.4.4 C-116

3 S Relocated this section to Chapter 7 for seismic-specific requirements.

FAS The Committee prioritized the important Primary comments as well as numerous editorial comments

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assigned to the FAS Subcommittee for consideration ahead of this Secondary item, and as such, the Committee will carry it forward to the next cycle for consideration.

291

Chapter 9

C-121 thru C-148

S Shear strength in multiwythe walls not noted; ballot 04-F-014 received outstanding negatives. Committee should continue working on the item.

FAS This item was balloted on 04-F-014 and received persuasive negatives. It was re-balloted on 05-F-014 which also had a persuasive negative. As the committee agrees with the TAC comment this is being balloted on Ballot 07-F-021. Persuasive negative received. Reballotted on 08-F-047. Negative received. No change made.


Y

300

9.1.8.2 C-125

70 S Previously, the modulus of rupture values were ‘directly proportional’ to the allowable flexural tensile stress values, but this proportionality is becoming looser with each edition of the Code. Commentary should reflect this.

FAS The committee agrees but the statement is still true. The values of the MOR values are in flux and may change further. The subcommittee discussions have not resulted in a ballot that is ready for Main committee but work will continue as time permits.

Y

302

Table 9.1.8.2

C-126

10 P The MoR values are out of sync with the flexural tension values of Table 8.2.4.2. The Allowable values were increased during the last Code cycle. But the MoR values were not adjusted similarly. Either increase the MoR values, or move the allowable values back down.

FAS The Committee prioritized other important Primary comments assigned to the FAS Subcommittee for consideration, ahead of this item and as such the Committee will carry it forward for consideration.

Y

320

9.3.4.1.1

C-137

55 P The word “if present” at the end of the sentence is confusing. It refers to what? The element is prismatic, simply supported, and the load is uniformly distributed. If there is a

F&S The Committee balloted a change consistent with the TAC Comment and ballot item 07-Q-13 that proposed to delete the phrase in question. The ballot items also made two

Y

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case where the resultant deflection is not symmetric, then please list.

grammatical corrections: a comma is inserted after “loading” and “results” is changed to “result”.07-Q-13 received a persuasive negative and a new ballot item was presented on Main 08-Q-013. In addition, the committee will consider changing “element” to “member” consistently throughout the documents, as has been done by ACI 318, as new business for the next cycle. Item passed.

350

11.2 C-164

3 S The chapter for strength design of unreinforced conventional masonry requires that P-Delta effects be considered, per Section 9.2.4.3. Should they also be considered for unreinforced AAC masonry?

AAC

The AAC subcommittee and Main Committee did not consider the use of P-Delta effects this cycle. The comment is a good one, however looking at the provisions of Section 9.2.4.3, they are not directly applicable to AAC, in particular 9.2.4.3.3 and 9.2.4.3.4. We propose that this item be considered new business in the next cycle because this is not an issue that needs to be immediately addressed with respect to life safety.

Y

361

Commentary – 12.1.1

C-179

60 S This graphic shows more information than the Code deals with (beyond scope) and may be misleading. Delete the reference to the overlap in the building paper. Delete the insulation (which does not meet IBC or IECC requirements in many jurisdictions) and state that insulation is not shown for clarity.

VGE

Due to higher priority items, the subcommittee has not resolved this item, but it will stay on our agenda.

Y

365

12.1.2 C-182

46 S There are many sets of industry recommendations to limit the deflection of masonry veneers, not

VGE


Y

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all of which are consistent. As an item of new business review available recommendations and incorporate as a minimum requirement in the next edition of the MSJC.

Should the code provide a code-required deflection limit for out-of-plane deflection of backing for veneer, based on the recommendations made by the references listed in the commentary? There are limits for vertical deflections of veneer supporting elements to limit veneer in-plane deflection. Why not for out-of-plane?

Where does the basis for the deflection limit of L/720 come from? BIA Tech Note 28B only lists a deflection limit up to L/600. Is there another reference for L/720?

366

12.1.2 C-182

49 S It would be beneficial for the commentary to provide additional guidance on what wind load levels should be used to calculate out-of-plane deflection, when evaluating backing stiffness against the industry-recommended deflection limits. Factored loads or service loads? What recurrence interval should the wind loads be evaluated at, the full design level or something less? Because the ASCE 7-10 calculations for design wind loads

VGE


Y

22





have changed to a “strength design approach” with a load factor of 1.0, the basic wind speeds and their recurrence intervals have all been increased. For example, in ASCE 7-05 for a Risk Category II building in the Midwest, the basic wind speed was 90 mph and the recurrence interval was 50 years; for the same building in ASCE 7-10, the basic wind speed is now 115 mph and the recurrence interval is 700 years. This change blurs the concept of service level wind loads versus design level wind loads. IBC acknowledges the idea of reducing the recurrence interval for wind loads used to calculate wall deflection, by allowing the wind loads to be multiplied by 0.42, as done within IBC 2012 Table 1604.3 “Deflection Limits.” Is this something that might be beneficial to mention in the MSJC commentary? Otherwise, designers may get the impression that a backing needs to be designed to L/720 for a wind load that only happens once every 700 years, which seems too stringent.

367

12.1.2 C-182

56 S There is a deflection limit listed at the start of this paragraph which reads “stud span length divided by 200 multiplied by the specified veneer thickness.” Is it intended to mean “stud span length divided by the product of 200 times the specified veneer thickness?” If so,

VGE

Balloted on Main 08-V-005A and 08-V-005B consistent with the TAC Comment. Negatives received. Item does not move into the working draft.

Item will be considered in the next cycle.

Y

23





can it be written this way?

368

12.1.2 C-182

63 S Is the referenced NCMA TekNote 16-3A an active TekNote? I’m having trouble locating it. Has it been superseded by another?

VGE

Balloted on Main 08-V-011A and 08-V-011B consistent with the TAC comment. Negatives received. Item does not move into the working draft.

Item will be considered in the next cycle.

Y

369

12.1.4 C-183

7 S The limitation on the use of dimension stone seems arbitrary. Is there a technical reason an anchored veneer cannot be stone? If not, remove this limit. If so, state why. The IBC and IRC do not have such a limit.

VGE


Y

372

12.2.1(c)

C-184

10 E Correct the reference to Section 1.1.3 (which addresses SI info.) Same in Section 12.3.1(c) as well.

VGE


Y

376

12.2.1(e)

C-184

16 S When designing an alternative-designed anchored veneer, is Paragraph 12.2.2.10.2.2 also excluded from the requirements? This paragraph requires that in high-risk seismic areas D E F that the maximum wall area supported by each anchor be reduced by 75% when designing veneer anchors prescriptively. Is this extra factor of safety also expected when doing alternative-designed anchored veneer, or should this paragraph be listed as an exclusion under the alternative design section?

VGE


Y

380

12.2.2.3.1.2

C-185

7 P For the paragraph regarding vertical support of anchored veneer with wood backing, when the changes to

VGE

Balloted on Main Committee Ballot 07-V-007 consistent with the TAC Comment. Persuasive negative was

Y

24





this paragraph were discussed in the TMS Spring 2012 Meetings, I believe it was mentioned that veneer on wood backing may be built taller than 30 feet if movement is accommodated and the veneer is supported at each story. If this is the case, can this paragraph be rewritten to follow the construction of 12.2.2.3.1.3 for cold-formed steel framing, which does allow this? If not, can an additional sentence be added to this paragraph to explicitly state that brick veneer on wood backing is not allowed above 30 feet (38 feet at a gable), regardless of what is supporting it?

found.

Item will continue to be considered in the next cycle.

381

12.2.2.3.1.4 & 12.2.2.3.1.5

C-185

13-22

S Recommend moving these two paragraphs into subparagraphs of 12.2.2.3.2. The first paragraph addresses veneer used as an interior finish. The second paragraph addresses veneer supported on wood construction. Both seem more appropriately located within a section dealing with support at floor construction. If persuasive, then their references within Paragraph 12.2.2.3.1 should be deleted.

VGE


Y

386

12.2.2.6.2

C-188

6 E In the context of the wood and steel stud standards, ‘framing’ refers to the entire assembly of components. This provision could be interpreted as permitting anchors to be attached to sheathing. Revise to clarify that veneer anchors are required to be attached to studs. Same for Section

VGE


Y

25





12.2.2.7.2.

394

12.3.2 C-191

17 S Add deflection limits for adhered veneer.

VGE


Y

396

13.2.1 C-194

4 P The design figure for glass block cites ‘factored’ wind pressure. Here it is ‘design’ wind pressure. In commentary Figure CC-13.2-1 is is ‘ultimate’. Be consistent and clear which load is correct.

VGE

Balloted on Main Ballot 07-V-013 consistent with the TAC Comment. Persuasive negative found.Item will continue to be addressed in the next cycle

Y

397

13.2.1 C-194

4 P As with other sections of the Code, add requirement that the design loads be determined in accordance with the legally adopted building code, or ASCE 7.

VGE

(Note TAC comment 397 was balloted concurrently with TAC comment 396). Balloted on Main Ballot 07-V-013 consistent with the TAC Comment. Persuasive negative found.Item will continue to be addressed in the next cycle

Y

401

13.3.2.1 C-196

11 S Clarify what loads are considered in calculating ‘total’ deflection.

VGE


Y

402

13.3.2.2 C-196

15 S In addition to the 12 ft height limit above support, add additional requirement for above grade plane.

VGE


Y

403

13.3.3.1 C-196

27 S Is the 200 lb/ft load a factored or unfactored load?

VGE


Y

411

14.2.3.1 C-199

27 S Is the 200 lb/ft load a factored or unfactored load?

VGE

Balloted on Main Ballot 07-V-026 consistent with the TAC Comment. Persuasive negative found.Item will continue to be addressed in the next cycle

Y

414

14.2 C-199

59 E Move “Design is based on the condition that gravity loads are reasonably centered on the walls.” to Commentary Section 14.2.3.1.

VGE


Y

41 14.2.3.5 C- 11 P ‘Service’ load is incorrect, I believe VG Balloted on Main Ballot 07-V-026 Y

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8 200 this should be ‘nominal’ load. If true, then this limit makes these provisions almost useless as the 18% of the MWFRS interior partition pressure from ASCE 7 often will exceed 5 psf.

E consistent with the TAC Comment. Persuasive negative found.Item will continue to be addressed in the next cycle

420

14.3.2 C-201

7 P Delete Section 14.3.2. These provisions were based on exterior walls subjected to out-of-plane wind pressures and are no longer applicable to interior partitions of enclosed buildings. Instead, add a prescriptive minimum (such as the vertical and horizontal distance between openings shall not be less than 3t or 24 in., whichever is less) to prevent unrealistic opening spacings.

VGE

Balloted response for the TAC Comment on Main 08-V-007:

“The Committee prioritized other primary comments as well as numerous editorial comments assigned to the VGE subcommittee for consideration, ahead of this item since the opening provisions in Chapter 14 were brought directly over from the Empirical provisions and as such have been applicable to partition walls for many cycles. The Committee will add as new business in the next cycle, consideration of this section.” Item passed.

Y

421

14.3.2 C-201

23 S What is a ‘virtual opening’? VGE


Y

426

14.4 C-203

10 S This section only addresses anchorage for horizontally spanning elements – what about vertically spanning elements?

VGE

Due to higher priority items, the subcommittee has not resolved this item, but it will stay on our agenda

Y

429

14.5.2 C-203

31 E Delete reference to Section 9.3.4.2, this is already covered by the reference to Section 5.2 and implies that ASD is not permitted.

VGE

Balloted on Main 08-V-008A and 08-V-008B consistent with the TAC comment. Negative was received on each item. Items do not move into the working draft.Item will continue to be addressed in the next cycle.

Y

437

A.1 C-205

61 S Please confirm the reference to Chapter 8 since other Chapters can

VG Due to higher priority items, the subcommittee has not resolved this

Y

27





be used for the design of lateral-force-resisting systems.

E item, but it will stay on our agenda

439

A.1.1 C-208

45 S Revise as:“Risk Category IV structures, or portions thereof, are not permitted to be designed…”

VGE


Y

440

A.2 C-209

5 S Where is the 35 ft height measured from? I assume grade plane?

VGE


Y

443

A.4 C-211

65 P There are several requirements discussed in this commentary section that are not in the mandatory requirements of the Code. If these are required, add them to the Code.

VGE

Balloted on Main Ballot 07-V-020A consistent with the TAC Comment. Item passed. Also balloted on Main Ballot 07-V-020-B - persuasive negative found. Reballot on 08-V-010. Negative was received. Item does not move into the working draft.Work will continue next cycle on this item.

Y

447

A.7.3 C-217

38 S Wythes bonded by ties in accordance with A.7.3 are by definition non-composite walls. Changes were made in Main Ballot 06-R-009 that assumes detailing in accordance with A.7.3 provides composite action. A negative was received on this ballot item, stating that this was incorrect. Subsequent discussion suggests that the Subcommittee should reconsider whether they wish to have this limit on adjustable ties applied to non-composite assemblies. Perhaps the option to provide either adjustable or non-adjustable ties, provided the appropriate tie spacings are provided.

R&C

This item has had a fair amount of discussion at recent subcommittee meetings, and the subcommittee believed the issue was settled. The comment indicates it is apparently still not clear.

The subcommittee would like to revisit this topic and determine whether there is an underlying misunderstanding of what this section is about. We propose to keep it on the list for further discussion.

Y

47 1.1 S-3 1 S Additional requirements are needed CR This item was balloted on 07-C-036 Y

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4 specific to the construction of masonry infills in accordance with Appendix B.

and received one negative that was found persuasive. This item will be considered by both the Infill and Construction Requirements subcommittees as future business in the next cycle.

480

1.4 B S-15 9 S As an item of new business, I would encourage the Committee to consider permitting (as an option) the use of historical data or even the unit strength method to provide preconstruction confirmation of compliance with f’m when prisms are specified on a job. Currently, in Quality Assurance Level C, compliance with f’m is required prior to and during construction. Many plans and specifications require similar compliance on other projects as well. If the prism test option for verification of compliance with f’m is used, preconstruction prisms must be constructed, and the expectation would be that the results would be available prior to the actual construction - thus the prisms should be constructed at least 30 days prior to construction. Since materials are not typically on the jobsite that far in advance, this is very onerous, and often an unrealistic requirement.It seems that an acceptable alternative would be to allow, as an option, historical data, and/or the unit strength method to be used for the preconstruction check. Then if prisms are desired for the actual

CR This item was balloted on 07-C-037 and received several negative votes. One was found persuasive. As suggested by the TAC Comment, the committee will continue to consider the comment as new business in the next cycle.

Y

29





construction, they can be constructed and tested. But at least the contractor would not be forced to try to make and test prisms before they typically have access to the actual materials.As a basis for such a change, (perhaps) recall that the UBC had permitted an option for historical data to be used to determine compliance with f’m.One final point. We say the contractor has the “option” to use either the unit strength method or the prism test method, so some may question why this is needed. Increasingly however, designers are specifying the tests required on the job, often including prisms. In such cases, the contractor no longer has the option to use the unit strength method. In addition, in rare cases, the contractor may want to use prisms during construction to “maximize” the materials he is expecting. In this case, the unit strength may be too conservative, but historical data may support the contractor’s desire to use those materials to achieve the specified strength. As such, for these reasons, having this as an option, could give the contractor reasonable options that would be verified later by actual prism breaks.

487

1.4 B.2.b

S-18 1 P New research is available to update Table 2 (Committee has been provided this research – “Recalibration of Unit Strength

CR This item was balloted on 07-C-041 and received several negative votes. The Construction Requirements subcommittee will continue to work

Y

30





Method …”). Please review this research and revise Table 2 accordingly.

on this complex item and attempt to resolve. Balloted on Main 08-C-080A, 08-C-080B and 08-C-080C. Item 08-C-080A passed. Negatives received on 08-C-080B and 08-C-08C. Item does not move into the working draft.

Note: A task group was established to continue work on this item in preparation for additional balloting opportunities if presented through public comment. If not, work will continue in the next cycle.

498

2.2 S-37 1 S I have recently become aware that lightweight grout (containing natural and manufactured lightweight aggregates) is being used with more frequency. It is also my understanding that designers are not considering the potential structural impact (i.e., bond strength) that should be considered when using lightweight grout in masonry construction. Add design provisions for lightweight grout (drawing on corresponding ACI 318 provisions as necessary) into the Code and Specification.

CR In order to adequately address this TAC Comment, several items must be carefully evaluated for possible structural implications. The TAC Comment suggests bond strength as a structural impact. The CR Subcommittee is not aware of what the appropriate bond strength (if any) is and what significant impact (if any) lightweight grout may have on the bond strength.

Should it be determined that the structural implications are not significant, this item may be more effectively addressed within ASTM, specifically, referencing lightweight aggregates within ASTM C476.

The CR Subcommittee will work with the Main Committee to keep working on this item in the next cycle.

Y

512

2.6 B S-51 56 P Delete Table SC-8 and its reference here. This data is sufficiently old so

CR The Committee can agree that the information provided in Table SC-8

Y

31





as to be no longer applicable to contemporary materials or construction and provides information that is likely to be more confusing than informative.

is historic, but it is applicable for grout now more than ever. Many people, particularly those associated with concrete, are thoroughly convinced that water is always detrimental to a cementitious mixture and nothing could be further from the truth with respect to masonry grout. As anyone in the masonry industry knows, fluidity, typically provided by water, is essential for grout placement and the excess water dissipates into the masonry units. This table is a vital tool in educating the people unfamiliar with masonry grout and water content.

As a matter of new business, the CR Subcommittee will explore additional Commentary to address new materials and construction and attempt to develop language that addresses new materials that may be unfamiliar to the distributer or end user.

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