Sandcastle Engineering: Finding Meaning in the Joys of Life

WRITTEN BY : Miggy Ballecer

LAYOUT BY : Regine Jeza E. Enclona

In a society where innovation is sought after day by day, it is often found in the most mundane things, though usually ignored. One of which is how sandcastles are built. With just a bucket, spade, or even bare hands, anyone could create a sandcastle and fill their hearts with joy. Primarily through the mixture of air, water, and sand, engineers can have a takeaway from such a familiar and fun structure.

However, there is more than what meets the eye in creating the best version of these ever-so-simple structures. It will not last by simply mixing sand, water, and air. It may seem simple, but building the perfect sandcastle has tons of considerations.

These structures are built upon the following concepts: surface tension, capillarity, and suction stress.

First in consideration is sand. Sand, which is inarguably the most important thing in a sandcastle, must be the right one. Although beaches are where we see them most of the time, the sand found there is not the best. Perfecting sandcastles require rough- edged or angular grains, as opposed to the round-edged grains found on beaches, brought by the continuous interactions with water and air.

Now, why is it that rough-edged sands work better? This type of sand inter-locks better, creating better strength when compared to round-edged grains.

However, water is what will make it work, make it stand. Without it, it is just sand and barely a castle. Simply put, water acts as the sand’s binder. Doing so can create “bridges” that pull the grains together, eliminating the space between them. Engineers refer to this pulling action of the water as suction stress.

With enough “bridges” formed, the sand and water mixture will gain strength and hold its form, a step closer to building a sandcastle.

Knowing that water is not enough to keep sand bonded together, finding the right balance between water is also important, since too much will destroy the compact bridge, and too little will fail to bond. In a practical setting, it is best to remember one part of water for every eight details of sand.

Air also plays an essential part in making surface tension happen. Without it, there would be no force restricting the behavior of water, freeing it to push the sand grains apart rather than pull it. Now this phenomenon of air-water interaction that pulls water grains, along with sand, is surface tension.

From this, one could see the concepts of engineering peek through, specifically in civil engineering. Finding the right balance between water and sand can be correlated to the cement-and-water ratio, where the proper ratio equates to the best concrete strength.

Sometimes, rather than pushing ourselves to find explanations in the most complicated ways, it is better to have fun and enjoy life and let all explanations flow through naturally. Just like building sandcastles, it is important for us engineering students to seek enjoyment in learning.