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How to order and receive ready mixed concrete

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How to order and receive ready
mixed concrete
Ready mixed suppliers report that even old-timers in the construction industry
can use advice on ordering.
re you kidding? After all
these years you’re going to
tell me how to order ready
mix?
A check of several ready mix firms
confirmed a long-standing suspicion that many men do not order
concrete correctly. And we’re not
talking about Joe Handyman, either.
Many old-timers in the construction industry fail to give all the information needed for the ready mix
supplier to provide the service he
would like to. True, the concrete gets
there, but the smooth integration of
concrete quality and delivery that
can spell worth-while savings for a
contractor is never fully realized.
A
Information for supplier
First of all, when the customer
calls in an order to his supplier, he
should include the job P.O. number,
if there is one. Some companies allow “hold orders” but have difficulty
with customers who take the hold
off only 15 to 20 minutes before delivery time and thus throw deliveries to other customers off schedule.
Listed below is additional information your ready mix supplier
should be given to ensure a smoothrunning operation.
1. Concrete quality and type.
Performance specification—If
you want the ready mix supplier to
be responsible for concrete performance, specify the following: compressive strength, slump, maximum
aggregate size, and air content.
[Note: Ready mix suppliers do not
guarantee strength of concrete, as
too many factors enter into the picture in providing a guaranteed compressive strength. However, they will
give information on cement and
aggregate requirements and may offer design specifications.]
Prescription specification—If you
want to be responsible for concrete
performance, specify the following:
cement content, water content,
maximum aggregate size, slump, air
content, and admixtures.
These are the minimum factors to
be specified; on some jobs, additional matters are included. For example, some prescription specifications
include
a
minimum
compressive strength provision.
If concrete with out-of-the-ordinary features will be required, it will
be to your advantage to consult with
your supplier well in advance of the
time you need the mix. This would
apply to lightweight concrete, an
unusual type of cement, white or
colored mixes, retarded set, or extra-high-strength concrete.
2. When? How much? Order concrete at least one day before you require it. Let the dispatcher know
how much you will need and the
delivery schedule that will best fit in
with your concreting plans. If possible, let your dealer know your tentative plans for concreting on the
entire job. Tell the dispatcher the
number of cubic yards needed per
hour (not the number of trucks)
and any variations in delivery desired during the day. Let your supplier know if you can accept concrete if it is raining; during cold
weather advise him what the minimum ambient temperature is at
which you will be able to place conc re t e. Fortified with this information in advance, he can schedule
d e l i ve ries to coincide with your
needs as closely as possible.
3. Where? Give your supplier the
exact location of the job and the
spot on the job where you want the
concrete delivered. If the job location is out in the boondocks, give information on access roads, the best
way to get to the project, any obstructions or danger spots along the
way, and other matters that might
affect prompt delivery. Mention if
the concrete is to be placed under
roof or outdoors. If the project is
particularly difficult to get to,
arrange to have someone meet the
trucks initially to show them the
route you want them to take. Give
the dispatcher the name and jobsite
telephone number of the man in
charge of concreting.
4. Changes. On even the best
planned and managed construction
jobs the unexpected can crop up to
throw the concreting schedule off.
When this happens your ready mix
supplier will be happy to reschedule
concrete deliveries to suit your new
needs. If a delivery must be canceled, call the dispatcher at least an
hour before the time delivery was
due. This will vary, of course, with
the time it takes to get from the
ready mix plant to the jobsite. If the
trip takes two hours, the cancellation should be three hours before
scheduled delivery time. If a change
in the concrete is needed, notify the
plant at least two hours before the
time the truck would have to leave
the plant. Should delays on the jobsite hold up concreting, let the plant
know so ready mix trucks won’t be
lined up at the job with concomitant deterioration of concrete quality and charges for truck waiting
time. It is advisable to telephone all
information in to the ready mix
plant, rather than call it in on a ra-
dio, since there will be less likelihood of misunderstanding.
Receiving ready mix
The time it takes to begin discharging ready mix from the truck
after it arrives at the jobsite and the
preparations for receiving the concrete will have an important bearing
on the ultimate quality and cost of
the concrete in place.
Before the first ready mix truck is
to arrive, have the formwork and
sub-base ready for receiving concrete. The formwork must be adequately braced and free of leaks. For
slabs-on-ground, the sub-base
must be compacted; free of organic
material, loose earth and mud;
moist but free of standing water,
and unfrozen.
Try to make it possible for the
truck to discharge directly into the
forms. If this is not possible, have all
transporting equipment ready.
Warn the driver of any septic tanks,
spots of soft fill, or other areas to be
avoided. Have your man directing
the ready mix truck stay on its left
side, clearly visible to the driver;
keep other workmen out of the way,
especially when the truck is being
backed into position for discharge.
Make sure that your man and the
truck driver are in agreement as to
the signals being used to direct the
d ri ver on the site. In addition to
watching the path being taken, your
man should keep an eye on the top,
wheels and chute to make sure they
do not collide with something. Remember, once the truck enters the
jobsite it is under the contractor’s
control and any damage done to
property is his responsibility.
It is best to check the route selected for the ready mix truck before
concreting commences to make
sure the ground is sound enough to
support the very considerable load,
and clearances are adequate for the
size of the truck. Typically, ready mix
trucks will be from 8 to 9 feet wide
and from 11 to 13 feet high. Your
ready mix firm will be happy to give
you the exact dimensions and
weights of the trucks to be used in
supplying your concrete.
Why bother with all this preparation? Because it will mean better,
more economical concrete in place
and fewer headaches. Also, many
of these steps can be taken care of
before the job starts (when things
a re not as hectic) and then need
not be repeated. Capitalize on the
ve ry real savings that can be
a c h i e ved by heeding these few
simple rules.
PUBLICATION #C690089
Copyright В© 1969, The Aberdeen Group
All rights reserved
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