By far, this is the most enjoyable lab session i've attended in NUS. The title of the lab was Concrete Mix Design. Our group was huge. Before this, the largest grouping i've had for doing a lab was four people. Today, there were 17 people in the group. The lab TA split us up into four different groups to plan on separate concrete designs. Our lecturer prepared this form, which i think is the template used by industries outside when mixing concrete, and through this design form, we planned out the ingredients in mixing our concrete.

It's the work you would see often only in construction site. But this time, the usual form of concrete you would normally see as the walls of your house, is in a flowable form. The main ingredients were water, cement, coarse aggregate (large rocks), fine aggregate (sand) and chemical admixtures (superplasticizer - for reducing the water content in the mix). Our group spent 1 to 2 hours planning the proportion of each ingredient. Many values, tables and graphs later, we managed to come up with how much of each item we would need to make our concrete paste.

Everything was thrown into this mixer, which resembled a cotton candy machine, to be mixed thoroughly. 12 cubic and 3 large cylindrical-shaped moulds were used. In 3, 7, 14 and 28 days time, a few of us would head down to the lab venue again to test on the strength of our concrete.

This lab session was indeed worth more on the experience than anything else. The planning phase, the gathering of ingredients, the mixing and the pouring of paste into the mould. This beats collecting chemicals for titration or pushing gliders into each other.