They should. I don't know that they do. This would definitely be a liability issue if design limiting (and driving) information was not passed along to the concrete contractor.
Check the current edition of the ACI Standard for the Recommended Practice for Concrete Formwork (ACI 347-78, or later). Lots of good info here as to what should be communicated, depending on the situation.
unless the engineer is reviewing the formwork shop drawings, this is between the supplier and the contractor and anything goes... I have never personally requested or reviewed shop drawings for formwork. Typical specifications around here give complete and total responsability for formwork design and adequacy (as well as any shoring or temporary supports) to the contractor.
Most formwork designs that leave our office have the pour rate specified in the notes. The only ones that don't are either supporting a vertical load or are for short forms with full hydraulic pressure.
If I remember correctly, the few times I've seen drawings from a supplier (probably EFCO or Dayton) they gave the pour rate and either gave or referenced the mix design.
I should have added to the above post, that vertical supports receive schedules and procedures when reshoring is required or the order in which areas are poured is important.
In your experiences with designing formwork and reviewing formwork, have you ever warned or seen warnings about slump exceeding 7" and its impact on pour rates?
Also, would you mind telling me what company you work for? If you don't want to share that information, that is fine. I am just trying to figure out if pour rate schedules are industry standard on concrete column form shop drawings and knowing a couple of firms that do this would help.
From my General Notes... please modify/scrap/or whatever...
Dik
CONCRETE FORMWORK
MATERIAL FOR CONCRETE FORMWORK SHALL CONFORM TO WITH THE CURRENT EDITION OF CSA O86.1, CSA O121, CSA O151 AND CSA O177
PLYWOOD FOR FORMWORK SHALL BE [EQUIVALENT TO COFI COFIFORM-PLUS | COFIFORM-PLUS | AINSWORTH POURFORM 107] AND SHALL BE GRADE STAMPED ACCORDINGLY
FORMWORK DESIGN DEFLECTION HAS BEEN LIMITED TO L / 180 WHERE L IS THE SPAN OF THE SUPPORTING FORMWORK ELEMENT. WET SERVICE CONDITIONS HAVE BEEN ASSUMED FOR FORMPLY DESIGN. SHORT TERM LOADING CONDITIONS HAVE BEEN ASSUMED FOR ALL FORMWORK ELEMENTS
MATERIAL FOR STUDS SHALL BE EQUIVALENT TO SPECIES S-P-F, GRADED #2 OR BETTER AND SHALL BE GRADE STAMPED ACCORDINGLY
MATERIAL FOR WALES SHALL BE EQUIVALENT TO SPECIES S-P-F, GRADED #2 OR BETTER AND SHALL BE GRADE STAMPED ACCORDINGLY
FORMWORK DESIGN PRESSURES ARE IN ACCORDANCE WITH THE CURRENT EDITION OF ACI 347. FOR FORMWORK LESS THAN [15FT | 5.0M] HIGH, THE MAXIMUM PRESSURE IS Cw x Cc x [150 + 9000 * R / T] AND FOR FORMWORK GREATER THAN [15FT | 5.0M] HIGH THE MAXIMUM PRESSURE IS Cw x Cc x [150 + 43400 / T + 2800 * R / T], WHERE R = RATE OF DEPOSITION AND T = TEMPERATURE. THE MINIMUM DESIGN PRESSURE OF 600 PSF HAS BEEN WAIVED TO COMPLY WITH CANADIAN PRACTICE
FORMWORK DESIGN PRESSURES ARE IN ACCORDANCE WITH THE RECOMMENDATIONS OF THE COFI WHICH ARE BASED ON THE CURRENT EDITION OF ACI 347. THE MAXIMUM PRESSURE, FOR A RATE OF PLACEMENT LESS THAN 2 METRES PER HOUR, IS 7.2 + 785 * R / (T + 17.8) , WHERE R = RATE OF DEPOSITION IN METRES PER HOUR AND T = TEMPERATURE IN DEGREES CELSIUS. THE MINIMUM DESIGN PRESSURE OF 600 PSF HAS BEEN WAIVED TO COMPLY WITH CANADIAN PRACTICE
THE CHEMICAL COEFFICIENT (Cc) HAS BEEN ASSUMED TO BE 1.2; CONCRETE SHALL BE TYPE 10, 20 OR 30 WITH A MAXIMUM OF 40% FLY ASH
THE CHEMICAL COEFFICIENT (Cc) HAS BEEN WAIVED TO COMPLY WITH CANADIAN PRACTICE
THE UNIT WEIGHT COEFFICIENT (Cw) HAS BEEN ASSUMED TO BE 1.0 FOR NORMAL WEIGHT CONCRETE
THE UNIT WEIGHT COEFFICIENT (Cw) HAS BEEN WAIVED TO COMPLY WITH CANADIAN PRACTICE
CONCRETE RETARDERS SHALL NOT BE USED
MAXIMUM HEIGHT OF FORMWORK SHALL NOT EXCEED [15FT | 5.0M] UNLESS NOTED
LIMITATIONS ON THE HEIGHT OF FORMWORK HAS BEEN WAIVED TO COMPLY WITH CANADIAN PRACTICE
MAXIMUM RATE OF POUR SHALL NOT EXCEED [7FT | 2.1M] PER HOUR
MAXIMUM CONCRETE TEMPERATURE SHALL NOT EXCEED 20 DEGREES CELCIUS
CONCRETE DENSITY SHALL NOT EXCEED [150PCF | 2400KN]
MECHANICAL VIBRATION SHALL BE LIMITED TO THE TOP [4FT | 1.2M] OF THE CONCRETE POUR
Yes the supplier does furnish a pour rate, but as you know there are many variables, including slump and consilidation. If concrete is consolidated too much, and the concrete is not placed in lifts then there is more liquid head on forms. As far as engineer is concerned for review, one should watch deflections that are caused by excessive pour rates. The forms could be safe and not blow out, but the deflection can be created when the plywood starts to give. That is known as pillowing of the forms. It becomes really noticeable when the sun is hitting the wall.
