Format of Concrete Mix Information to be supplied by Purchaser to RMC manufacturer

archdevil

Star Member
Sep 21, 2017
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India
Format of Concrete Mix Information to be supplied by Purchaser to RMC manufacturer
We often observe the negotiation for the purchasing of concrete is mostly done on price and grade of concrete, by a Purchase Authority with the RMC Manufacturer.
In order to get the order and make the concrete within the budget of purchaser, RMC manufacturer plays with the concrete mix design.
Even though the concrete mixes with low cement and high amount of flyash or ggbs can do attain the strength which is required in lateral stage and by the age of 28 days or more.

At Project site, when there is timely completion of activity is require, a project may stuck due to low strength gain at early age of concrete say at 3 or 7 or 14 days age. If the concrete wont achieve required strength for facilitating the de-shuttering of formwork, saving in the cost of concrete may lead to losses in terms of delays occurs in the project.

Best practice is to, along with the grade of concrete a purchaser should also send the other requirements in concrete to ensure no other properties does impact the progress and cost of the project.

I have attached herewith the format of Format of Concrete Mix Information to be supplied by Purchaser to RMC manufacturer, this format will help purchaser to negotiate correctly with RMC concrete manufacturer and Safe execution of the Project.

The format consist of following information to be supplied by purchaser.
MIX CODE
Grade of concrete
Specified Minimum Cement Content (kg/m3)
Specified Maximum Cement content (kg/m3)
Specified Maximum Free Water -Cement Ratio
Nominal Maximum Aggregate Size
Cement Type and Grade (if preferred)
Mineral Additives (Pulverized fuel ash/Slag/Others) (Kg/m3)
Target Workability at Site
Maximum Temperature of Concrete at the Time of Placing, if required
Method of Placing
Any Other Requirements (Early strength, air content, chemical admixtures etc.)
Concrete Testing (Frequency)
Material’s Testing (any non routine requirements)
Alternatives to be Offered: YES/NO
Method of Curing to be Used by Contractor
Quantity (m3)
Any other important information, such as exposure condition, class of sulphate resistance etc.

NOTE—Additional proforma for further information may be used, such as for specific test rates to be achieved for concrete or rawmaterials, exact method statements of the contractors proposed site practice.
 

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