Concrete Specs.

[PEinVA]

I'm almost 2 years out of school and our office has a small steel building (5 stories) starting construction soon. I'll be the CM for our office for the job, with my boss always available for me. I haven't been involved in specifications much for my work here so far, only some for repair work in a PT situation, but not really for a job this size for new construction. Can someone give me some advice on the following questions submitted in response to the project specs.

Thanks!

1. Section 03100-3, 2.2, C, 1, 2, and 3. is it acceptable to substitute corner chamfer materials manufactured by other manufacturers and that wood chamfers can be provided in lieu of poly vinyl chloride (PVC) strips, steel or fiberglass?



2. Section 03100-4, G, 1, 2, 3, and 4. Is it acceptable to provide industry wood formed keys as an option manufactured from steel or metal for slab on grade construction joints and contraction joints? Slab on grade contraction joints will be provided using “soff cut technology”.



3. Section 03100-5, 3.2, D. “Removable Panels” (Inspection Pockets) will not be provided in walls, columns etc. to facilitate cleaning, drainage, and inspection. All formwork to be cleaned using compressed air or water prior to the satisfaction of the on-site testing and inspection representative in accordance with industry standard practice. Is this acceptable?



4. Section 03100-5, 3.3, C, a. Class A Form Surfaces Finish are assumed to be required at form surfaces exposed to view from outside the building. Class B Form Surface Finish will be provided in Parking Garage Areas and Stairs. Please confirm.



5. Section 03100-7, 3.3, H, I, and J. Our concrete subcontractor intends to propose alternates to specified stripping time limitations. CCC will submit an engineered shoring and stripping sequence for approval as specified. Industry Standard Practice will be followed.



6. Section 03310-2, 1.4, B. Because of industry and regional shortages, providing single source concrete, cementitious materials, sand, aggregates, and admixtures can not be guaranteed. Is this acceptable?



7. Section 03310-7, 2.3, C, 1, 2, 3, and 4. We have assumed slump limits will be changed. Minimum slump to be changed to 4” +/- 1” for concrete not containing HRWR. Slump limits of maximum 8” for concrete containing HRWR. Is this acceptable?



8. Concrete subcontractor will submit a plan for approval of slab on metal deck construction joints. Joint locations may exceed the limit specified in one or more directions. Clark will consult with the E.O.R. on joint layouts for approval. (FYI only)



9. Section 03310-15, 3.6, A. Temporary protection of concrete form construction traffic, weather or mechanical abrasion for fourteen (14) days after placing is extremely difficult to ensure and beyond our standard operating practice. Clark will provide standard protection of concrete for initial curing period or seven (7) days. Please confirm this is acceptable.



10. Section 03310-15, 3.6, B. Protection of exposed concrete form staining can be provided to the extent that we can control our operations, eg limit vehicle traffic, storage of materials, etc. However, we can not limit any staining originating from the environment, specified mixes, or elements beyond our control. Please confirm acceptability.


I appreciate any input guys!
RC

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[hokie66]

RC,

Who is asking the questions? Bidder or awarded contractor? This would influence my responses somewhat, and your boss should be able to give you guidance in that regard. Some of the questions are phrased awkwardly, so be sure you understand what is being asked.

My thoughts as follows:

1, 4, 10 are finish issues which should be discussed with the architect, and the answers will depend on the usage of the building.

2. I don't use keys, so no particular comment. Sawn joints are preferable if these are lightly loaded slabs, and soffcut joints are good if done properly.

3. The issue is not the cleanliness of the formwork, but making sure there is not debris left in the bottom of the form. To blow out sawdust, tie wire, lunch wrappers, etc. requires a hole somewhere.

5. I think you are obliged to consider his proposals as to stripping. But the final decision is yours, and don't be intimidated by "industry standard" assertions.

6. I would insist on a single source supply for the readymixed concrete. If the source of materials changes, the supplier should be required to submit new mix designs.

7. Slump requirements will depend on your job. No specific comment.

8. That is the way it should be done.

9. I sympathise with the contractor, but you should find out how he intends to cure the concrete after the initial curing period.

 

[PEinVA]

hokie66,
Thanks!

I pretty much agreed with all your comments, and thank you for your input.

I was a little worried about #3 because we had a conference call about the list this morning with the contractor (awarded contractor) and my boss didn't seem interested in forcing this on him, but wanted to discuss it with the concrete sub, to make sure they reviewed the forms before being closed in, and that was enough.

Also, #6 - that is what we're planning on doing, requiring new mix designs for any changes.

Thanks!

RC

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[jike]

Regarding #6, I would also insist on single source ready mix supplier. The GC is trying to set himself up to shop among suppliers. Switching ready mix suppliers or even cement suppliers on an architecturally sensitive job can give different colors.

Regarding #7, he wants to relax your slump standards to make it easier to place and finish. Be careful!

 

[hokie66]

RC,

You are welcome. Glad to be of help. And I agree with Jike's comment on the slump. Your contractor actually sounds responsible in addressing these issues early on, but you still have to be vigilant. Good luck with the project.