Choosing Cement (and Why Brand Obsession Is Mostly Noise)#

During construction, one of the first questions people start asking—sometimes obsessively—is:

“Which cement brand are you using?”

There is nothing inherently wrong with preferring a reputed brand. But in most residential projects, this fixation slowly turns into an unnecessary expense with very little real-world payoff.

If you’ve read Chapter 12:In Concrete We Trust, you already know why:

Cement brand matters far less than concrete design, grade, workmanship, and curing.

Any ISI-certified cement, when used in the correct quantity for the intended concrete grade, will perform exactly as expected. Once the bag is emptied into the mixer, there is no magic left in the logo.

The Three Cement Types You Will Actually Encounter in Kerala market#

Before discussing what is “better” or “worse,” it helps to understand a simple reality:

For residential construction in Kerala, there are only three commonly available types of cement.

1. Ordinary Portland Cement (OPC 43 and 53)#

OPC — Ordinary Portland Cement
This is the traditional, clinker-rich cement most people still think of as “pure cement.”

OPC reacts fast, generates higher heat, and gains early strength quickly. These properties make it useful for specialized applications—but poorly suited for typical residential construction, especially in hot, humid environments with variable workmanship.

Today, OPC is increasingly difficult to source. This is not because it is superior, but because it is largely unnecessary. Regulatory pushback exists for good reasons: durability, sustainability, and long-term performance.

2. Portland Pozzolana Cement (PPC)#

PPC — Portland Pozzolana Cement
PPC contains fly ash, a by-product of thermal power plants.

This is not a compromise. Fly ash improves concrete by:

Reducing permeability
Improving long-term strength
Lowering heat of hydration

PPC is slower-reacting and more forgiving than OPC, making it well-suited for most residential RCC work.

3. Portland Slag Cement (PSC)#

PSC — Portland Slag Cement
PSC contains granulated blast furnace slag, a by-product of steel manufacturing.

Like PPC, PSC improves durability—but it goes one step further:

Even lower permeability
Better resistance to aggressive environments
Greater tolerance for real-world site conditions

In Kerala’s construction environment—where workmanship variability is the norm, not the exception—PSC tends to be the most forgiving option.

What Actually Matters (And What Doesn’t)#

Whether you choose PPC or PSC, one rule never changes:

Use the correct number of bags for the designed concrete grade.

No brand—and no cement type—can compensate for under-cemented concrete.

Durability comes from:

Proper cement content
Controlled water–cement ratio
Good compaction
Proper curing

Brand loyalty does none of these.

The Ready-Mix controversy#

A few years ago, when I asked a contractor whether he would be willing to work with a ready-mix supplier, his answer was immediate:

“Sir, they add fly ash instead of cement. When we mix at site, we know exactly what we are adding. Don’t buy ready-mix.”

I trusted him.

So did many others. Some still do.

What most people don’t realize is this:

The cement bags sold today all brands are already blended with fly ash or slag.

Whether concrete is mixed at site or delivered in a transit mixer(RMC), fly ash is already part of the cement itself. The comforting belief that site-mix equals “pure cement” no longer reflects reality.

This misunderstanding becomes clearer when you look at what the code actually allows.

IS 456:2000 permits a minimum cementitious content of 340 kg/m³ for M35 concrete. Yet, in practice, a nominal M20 site mix if properly made consumes 400 kg/m³ of cement.

This does not mean the M20 site made mix is better or more durable. Nominal mixes are often presented as safer and more “honest” than designed mixes, but that confidence is misplaced.

Nominal mixes assume poor control—uncertain water–cement ratio, inconsistent aggregate grading, and variable workmanship. Extra cement is added as a crude safety margin to make sure strength is achieved despite these uncertainties.

A properly designed M35 mix from a ready-mix plant achieves strength and durability not by adding more cement, but by controlling water, aggregate grading, and adding admixtures. Lower permeability—not higher cement content—is what improves durability.

The real difference between site-mix and ready-mix is not the amount of cement used, nor the use of permitted admixtures like fly ash or GGBS.
It is control.

By control, we mean:

precise measurement of materials
a known and consistent water–cement ratio
properly graded aggregates
controlled use of admixtures
repeatable, machine-based mixing

Ready-mix concrete is durable because these variables are controlled.
Site-mix concrete fails not because of intent, but because these variables are left to chance.

Cement Is Perishable#

Cement is a reactive material.
It slowly loses effectiveness with time and humidity, even when bags look normal.

There is no reliable visual test for “old” cement.
It does not smell, discolor, or warn you.

That leaves one practical rule:

Do not use cement stored for more than 3–4 months.

Beyond this, strength gain becomes unpredictable, water demand increases, and durability suffers. The damage is not dramatic. It is everywhere and permanent.

At site, cement must be:

Stored off the ground
Kept dry
Covered properly, preferably with a plastic sheet to prevent interaction with humidity

Ignoring this does not cause immediate failure.
It produces concrete that quietly underperforms for its entire life.

The Only Takeaway That Matters#

Brand obsession wastes money.
Correct mix proportioning and curing determine durability.

Durable concrete comes from:

Any ISI-certified PPC or PSC
Fresh, properly stored cement
Correct cement quantity
Controlled water
Proper curing

Everything else is noise.

Concrete does not care what you believe.
It only responds to control.

Cement Brand Mania