As a builder or contractor, how do you choose the right cement for your construction project?
In Bangladesh, the construction landscape is dynamic. Climate, soil conditions, and project types vary from one another. As a result, selecting the correct type of cement is crucial. It will dictate the structural integrity, longevity, and durability of cement.
Whether you are building a high-rise condo in Dhaka, a coastal farmhouse in Cox’s Bazar, or a rural home, the choice of cement can make or break the property.
In this guide, we walk through the kind of cement available in our country. Also, explore how they differ and the factors to consider before making your decision for your build.
Why Choosing the Right Cement Is Important
A cement is not just a glue that binds sand and stone.
For any construction project, cement is the foundation. It provides durability, resistance, and strength to the infrastructure.
In Bangladesh, we experience an array of seasons across different cities. It includes hot summers, high humidity, saline soils, and monsoon rains. As a result, it is crucial for cement to display solid performance under aggressive conditions.
Therefore, choosing the wrong type of cement can be costly. It must suit the needs and requirements of your project. If not, it can lead to cracks, early aging, corrosion, or structural failure—especially in sulfate-rich or coastal environments.
Overview of Cement Types in Bangladesh
Ordinary Portland Cement (OPC)
OPC is used for structural frames, RCC components, fast-track projects, and urban infrastructure. In Bangladesh and globally, OPC is the most widely used cement.
It is manufactured by grinding clinker with gypsum and contains a high percentage of calcium silicates. OPC is certified with strength grades such as 42.5N and 52.5N. At the same time, it complies with BDS EN 197-1 CEM I or ASTM C150 Type I standards.
Advantages
Rapid Strength Gain: OPC is ideal for high-rise buildings or bridges where achieving early strength is important. With high calcium silicate, it can achieve 60%-70% of its 28-day strength within 7 days.
Time Efficient: If your construction project is time sensitive, OPC can help you with it. Its early strength and quick setting mean earlier removal of formwork. As a result, you can progress to later construction stages faster.
Consistency in Performance: OPC has been used globally for over a century. The cement is backed by a huge body of research and experience as to how it behaves in different mix ratios, environments, and conditions. As a result, it is easy to use in engineered mix designs and testing.
Limitations
High Heat of Hydration: In large pores, OPC does generate enough heat to cause thermal cracking. It is commonly seen in the summer. The solution is to cast the cement at night or early morning when its temperature is lower. Or, use PCC or other blended cement to lower the heat of hydration. Also, you can apply surface curing or use thermal insulation blankets.
Vulnerable to Sulfate Attack: OPC relatively contains a higher amount of tricalcium aluminate. As a result, it is susceptible to sulfate attack in coastal or marshy areas like Cox’s Bazar or Sundarban.
Investment: In general, OPC is more expensive than PCC. It is due to higher clinker content and a more energy-intensive manufacturing process.
Portland Composite Cement (PCC)
In Bangladesh, PCC is interchangeably known as Portland Pozzolana Cement. It can be applied to all kinds of residential and commercial buildings. However, it is perfect for boundary walls, masonry, internal slabs, and structural work.
This cement contains pozzolanic materials like fly ash, volcanic ash, or slag, which is mixed with Portland clinker. The typical blending ratio is about 15% to 35% pozzolana. It is an ideal option for construction projects in coastal towns like Barisal or Khulna, as it consists of sulfate resistance.
Advantages
Durability: The pozzolanic reaction reduces free lime. It enhances the chemical resistance, particularly to sulfate and chloride attack. Due to high durability, the permeability is low. As a result, it reduces the risk of steel corrosion.
Low Heat of Hydration: As mentioned earlier, PCC is an ideal option for large foundation and mat slabs. It minimizes thermal cracking.
Improved Workability and Finish: The finer particles of the cement create a smooth mix. It can be used effectively for plastering, bricklaying, and surface finishes.
Eco-Friendly and Cost-Effective: PPC is a blended cement. As a result, it reduces carbon dioxide emissions and clinker consumption. The product is both sustainable and economical at the same time.
Limitations
Slower Strength Gain: In comparison to OPC, it has a slower strength gain. This cement reaches 50% to 60% of its final strength in the first 7 days. As a result, it can cause a delay in structural phases and the construction timeline.
Curing Sensitivity: PCC requires a longer and proper curing period to develop its full strength. Also, to prevent any shrinkage cracks from occurring in the future.
Sulfate Resistant Cement (SRC)
SRC is most suitable for coastal construction. For projects near the sea or bridge foundations, it can be applied in the pile and foundation zones. Additionally, it can be used for marine infrastructure, basements, and wastewater treatment plants.
It is designed with low tricalcium aluminate to protect the concrete against any sulfate attack. It conforms to the ASTM C150 Type V or equivalent standards.
Advantages
High Resistance to Sulfates: SRC prevents ettringite formation, which causes expansion and cracking.
Durability in Aggressive Conditions: Due to its high durability and nature of the cement, it is applied to below-ground structures. As mentioned earlier, it includes marine piles or sewer lines that are exposed to chemicals.
Moderate Heat of Hydration: It reduces the thermal stress in mass concrete.
Limitations
Availability in Retail: This cement is mostly used in large-scale government or industrial construction projects. It can be a challenge to get hold of it via local dealers or retailers.
Not Effective Against Chlorides Alone: In marine or coastal environments, chloride-induced corrosion is an issue. As a result, SRC needs to be paired with waterproofing or extra protective measures.
Highest Investment: An overall investment in SRC is quite higher in comparison to other cements. It is due to limited production, availability, and specialized clinker to manufacture it.
White Cement
White cement is applied for interior or decorative purposes. It is used for polished terrazzo floors, finishing plaster, and colored concrete. Or, as a grout for luxurious tile installation.
This cement is known as a refined form of OPC, with minimal iron and manganese. If done right, the cement achieves a bright white appearance.
Advantages
Aesthetic Appeal: It is ideal for exposed surfaces, such as precast decorative elements and wall finishes.
Smooth Surface Finish: White cement is a top choice for premium plaster work or tile setting. I
Heat Reflectivity: A surface with white cement reflects more sunlight. As a result, it reduces the heat absorption of a property. It is particularly useful for terraces or decorative roofing systems.
Factors to Consider When Choosing Cement
Project Type
Residential
When it comes to home construction, PCC is the preferred option. It is known for its durability, crack resistance, and workability around the product.
It performs well for plaster, walls, and masonry while reducing long-term maintenance. In case the residential project needs a faster timeline, OPC can also be used for its early strength feature.
In the coastal areas, foundations should be cast with SRC or sulfate-resisting PCC to avoid corrosion and concrete breakdown. At the same time, white cement can be used for tile joints or decorative finishes.
Commercial
For high-rise buildings or fast-track commercial projects, OPC is the ideal choice. As mentioned earlier, it is known for its high early strength. It is crucial for formwork cycles to move fast.
For commercial interiors, PCC can be applied for smooth finish in plaster, masonry and flooring. Also, white cement is quite popular in office lobbies, malls, or office cladding where visual appeal is important (Civil Today, 2022).
Industrial
When it comes to industrial environments, chemical durability is a key factor. Therefore, it is crucial to use SRC in chemical plants, factories, and sewage structures. It helps to protect against sulfate-rich water or industrial waste (The Constructor, 2023).
However, OPC or PCC should be applied for heavy machinery pads or vibration-prone elements. Also, it can be used for office or storage units. But SRC is non-negotiable for floors or building foundations in aggressive soil.
Environmental Conditions
Bangladesh’s hot summer month helps to accelerate cement setting. In the case of OPC, it may set too fast. As a result, it increases the risk of thermal cracking.
However, with PCC, it has slower hydration. Therefore, it is a safer option for mass concreting and large pores (UltraTech Cement, 2023).
In the winter months, OPC performs better due to faster strength gain. In the monsoon conditions, it favors PCC since humidity aids curing.
Nonetheless, OPC is more rain resilient during early setting. It might be a preferable option for quick pours like slabs.
Load and Durability Conditions
For load-bearing structures like columns and bridges, OPC 52.5N or above is ideal. However, in long-term durability, PCC and SRC do better. It is due to their low permeability and crack resistance.
For instance, in saline soil or flood-prone areas, SRC prevents sulfate and chloride attacks. It is critical for preventing steel corrosion and concrete disintegration (The Constructor, 2023).
Total Budget
In the market, PCC usually costs 10 tk to 20 tk less per bag than OPC. For large-volume construction works, it will be one of these two. The construction deadline can play a key role in deciding which one to choose.
On the other hand, SRC is costlier, with 550 tk to 600 tk per bag, but it is ideal for chemically aggressive environments.
For aesthetic or decorative works, white cement can cost up to 150 tk per kg. As mentioned earlier, it cannot be applied in load-bearing components.