bismillahirrahmanirrahim,
Wondering why the concreting process in our team didn’t meet the planning….Actually we have planed to do it last monday..but there were some problem to be fixed, causing many thing steps back from schedule. =(
Don’t you wonder what happend in the middle of th the process?? hohoho…I swear you would laugh surprisingly……^_^
As you know from my previous posting, our competition is about how to meet 25 MPa compressive strength closely….As a conscequency of this matter, we have to design the mixing plant of the concrete in such a manner so that this purpose fufilled.
The strategies were firstly, reduce the deviation standard (Sd) so that the formula become :
Fc=F’c +1.64 Sd ==> Fc=F’c
(our F’c design is 25 MPa, without the deviation standard)..
this condition push us to take care of the properties of the materials, this is the second strategies.
As you know (for you the civil engineer ^_^ ) many things are below our attention in order to design the concrete mixing plant truly, one thing is the gradation of the aggregate …
We usually use two kind of aggregate, the rought aggregate which is rock, the other is smooth aggregate which is sand.
We have to control those two kind of aggregate….
It is difficult for us…
from the experiment of those two kind of aggregat, the rock and the sand, one of it is appropriate according to the standard specified (we use ASTM code), that is the Sand…
but…(this is the problem, actually ^_^ )
the rock is inappropriate according to the ASTM standard….which is mean we have to manipulate the gradation, in order to meet the standard…
The only way (in our opinion), possibly to be done is order the quantity of each diameter of the aggregat so that we can reach the standar…How?
this is the silly one hehehe…
we filter all of the aggegat we bought from the material retailer (it is about 1/4 m3) into the standard sieve, so that we can split-ups the aggregat by its diameter…
there are 4 types of diameter which are 25 -> 19 -> 9.5 -> 4.75 -> 2.38 (all in mm)
We have gotten the 25 ( we need 0 kg of it), 19(we need 47,..kg),9.5(we need 37,… kg), and 2.38(we need 5,..kg) mm BUT..we were lack of diameter 4.75 mm (we need 37,..kg but we have only 10 kg)
Oh My god!! so…we must find out the diameter 4.75 aproxiamately 27 kg??!!! from where can we find those kind of thing?? because we have had no more aggregate left…hiks..hikss…
but thanks 4JJI..we have the crusher in our lab..so that we can find 4.75 mm from the bigger aggregate (which have not been used already) crush into the crusher…
actually we can only get 16 kg from the crusher…
we have no more aggregate diameter bigger than 19 mm to be crushed into the crusher (the machine is only work for the diamete 19 mm only)…
so? how about the last 11 kg?? we still lack of it…
our grey brain think……AHA!! we get another silly idea…
let’s do it by our hand….what is that mean??!! let’s crush the 9.5 mm unused into 4.75 mm…WHAT???!! do it manually….for 11 kg ??!!
hiks..hiks….actually we did this idea …..crushing manually is really…really…heart eaten hehehe….
pegel boow!!! 11 kg gitu looh…even if we were three…but 11 kg is really abundant!!
edi used 5 kg hammer to crush the 9.5 mm aggregat, wijono used the silinder metel, and I used an half kg hammer…
At least, as edi said, free fitness to build our hand muscles- biseps and triceps-hehehe
we need about 2 days to fufilled 11 kg of aggregat diameter 4.75 mm
That’s why our concrete mixing plant delay until the next tuesday..phuh such a difficult..and we need patient to do it…
but…at the end of crushing time, we felt proud of our work….
Prooving the YES WE CAN !!!
semoga..semoga hehehe….
^_^
