One time, our teacher instructed us to make hallow blocks using different mixtures of ordinary Portland cement. We are then to test the strength of each hallow blocks made. Being the only girl in our group, I always ended up as the secretary jotting down the results of the test while the boys get to mix and mold the hollow blocks. Oh well, after the curing period (time for the cement to harden), we laugh so with our finish products because we made a hollow block that is so tough that we actually wasted too many bags of ordinary Portland cement. Yeah, it was sturdy alright but it was a failure because we weren’t that efficient and cost wise.