Assignment 03 – fluid form – group

Assignment 03 – Fluid form

Johan Wallhammar, Marieke van Dongeren

 

Concept: Spritzing concrete in several layers – like 3D-printing or spritzing cream on a cake

2 experiments:
– 1 on flat surface (Marieke)
– 1 on leaning surface (Johan)

Followed given recipe – with extra cement for a less fluid mix.

Four attempts were made at different times – so concrete was more cured:
– 1^st attempt – directly when concrete was mixed
– 2^nd attempt – 30 minutes after concrete was mixed
– 3^rd attempt – 60 minutes after concrete was mixed
– 4^th attempt – 80 minutes after concrete was mixed

Concrete mixture finished at 10.58.
– 1^st attempt started at 11.03 – finished at 11.10
– 2^nd attempt started at 11.30 – finished at 11.40
– 3^rd attempt started at 12.00 – finished at 12.05
– 4^th attempt started at 12.20 – finished at 12.25

 

1^st attempt:
– heavy
– very hard to get concrete out of spritzer – we almost got cramps in our hands afterwards
– Mixture spritzed on flat surface was stable and could be built in several layers
– Mixture spritzed on leaning surface not as stable – fell over

 

2^nd attempt:
– slightly less heavy, more fluid than 1^st attempt.
– more smooth surface

 

3^rd attempt:
– Perfect fluidity for spritzing –lighter
– more stable

4^th attempt:
– slightly more fluid than 3^rd attempt – less stable

 

Comments:
Everything got wetter and more fluid as time passed – contrary to our expectations.
Johan had a bigger opening in his spritzer than Marieke. This might result in the different appearances of the tests.
The concrete was a lot blacker when we mixed it – after curing it got lighter.

 

Mix design:

mass (grams) parts percentage of cement cement 1250 1 sand 2156 1.72 172.48% fly ash 280 0.13 22.40% silica 140 0.50 11.20% water 420 3.00 33.60% super plasticizer 18 0.04 1.44% pigment 2.5 0.14 0.20% total 4266.5 241.32%