When I started my 6-month internship with MICADA (Minor Irrigation & Command Area Development Authority), Haryana Government, I expected to observe. What I didn't expect was to be standing knee-deep in the construction process of a full underground RCC water tank — from the very first stake in the ground to the final surface finish.
This article is my attempt to document everything I witnessed and learned. Not the textbook version — the real version, with dust, concrete, and the kind of problem-solving that only happens on a live site.
Reinforced Cement Concrete (RCC) is concrete that is strengthened by embedding steel reinforcement bars (rebar) inside it. This combination gives structures both compressive strength (from concrete) and tensile strength (from steel), making it ideal for underground water tanks, foundations, beams, and slabs.
The Full Construction Sequence — Stage by Stage
Here is the complete sequence I observed for the underground RCC water tank at the MICADA site:
What I Learned That No Textbook Tells You
1. Cover Blocks Are Not Optional
In textbooks, "clear cover" is just a number. On site, I watched labourers carefully place small concrete cover blocks under each rebar layer to maintain the design spacing from the formwork. Without them, the rebar can touch the surface, leading to corrosion over time. This one detail directly affects the structure's 50-year life.
2. Concrete Vibration Matters More Than You Think
A needle vibrator was inserted into the concrete every 30–40 cm while pouring. I initially thought it was optional. The site engineer explained that without proper vibration, air bubbles get trapped — creating voids called honeycombing — which severely weakens the structure. Every insertion, every movement mattered.
3. Curing Is The Most Neglected Step
I was surprised to see how much time and effort went into curing. Concrete gains only 30% of its strength in the first 3 days — the remaining 70% comes from proper hydration over 28 days. On the MICADA site, the supervisors were strict about jute bag moisture and water ponding schedules. This discipline is often skipped on private sites, and it's why many structures fail prematurely.
4. The Excavation Depth Tolerance
The excavation was not just "dig until it looks deep enough." The engineers cross-checked the base level using a dumpy level after every major excavation phase. The tolerance was ±25mm. Anything more meant re-excavation or compensating with extra PCC thickness — both costly.
The gap between textbook civil engineering and site civil engineering is significant. The theory gives you the framework — but the site teaches you why every detail in that framework exists. If you can, visit even one live RCC construction site before you graduate.
Quality Checks I Observed on Site
- Slump test for concrete workability before every major pour
- Cube testing samples prepared and sent to lab (M20/M25 mix)
- Rebar diameter and spacing cross-checked against structural drawings
- Level checks at foundation and at each slab before concrete is poured
- Formwork inspection for leakage before pouring begins
Final Thoughts
Watching the complete lifecycle of an RCC water tank — from a bare patch of soil to a finished underground structure capable of storing thousands of litres of water — was one of the most educational experiences of my engineering journey.
The real lesson wasn't about the concrete mix ratio or the rebar spacing. It was about attention to process. Every stage has a purpose. Skipping or rushing any one of them has consequences that might not show up for years — but when they do, they're expensive and potentially dangerous.
If you're a civil engineering student, make sure you find a way onto a real construction site before you graduate. No amount of lectures or textbooks can replicate what a single day on site teaches you.
