Barge cement is a type of cement used for construction projects involving water, such as bridges over rivers or building foundations in marshes. It has some advantages over regular cement in these situations, which is why it was developed. Let’s take a look at what makes barge cement different and whether it is actually stronger than regular cement.
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What is barge cement?
Barge cement, sometimes called marine cement, is a special type of cement blended for use in or near water. It was developed in the 1920s to build infrastructures like bridges and tunnels across bodies of water.
Regular cement can weaken when exposed to water for long periods of time. Barge cement undergoes additional processing and contains additives that make it more water resistant. The key differences are:
– Lower ratio of calcium aluminates – These compounds hydrate more rapidly and can cause early stiffening when exposed to water. Barge cement has a reduced ratio.
– Higher ratio of blast furnace slag – Slag makes the cement more water-resistant. Barge cement contains up to 60% slag.
– Water reducers – These chemical additives help barge cement hydrate properly despite water exposure. They keep the water to cement ratio consistent.
– Lower hydration temperature – Barge cement is designed to hydrate at slightly lower temperatures, down to 4°C. This helps for underwater applications.
So in summary, barge cement undergoes specialized processing and blending to make it suitable for prolonged water exposure during construction projects over or in water bodies.
How is barge cement used?
Because barge cement provides better performance when exposed to water, it has become an important building material for certain infrastructure projects:
– Bridges – Building bridge footings or piers surrounded by water. The cement must resist erosion and corrosion.
– Dams – Barge cement is used for dams due to the constant water pressure and flow. The cement has to harden properly despite moisture.
– Oceanside structures – For structures located in or near the ocean, like docks or foundations, barge cement protects against saltwater.
– Underground applications – Since barge cement can hydrate at lower temperatures, it is good for pouring underwater foundations.
– Canals – The walls and foundations of canals need a water-resistant cement formula like barge cement.
So in projects where the concrete will be constantly exposed to water, either underground, partially submerged, or located riverside or oceanside, barge cement is the preferred material over regular cement.
Strength and performance
Now let’s discuss the key question – how strong is barge cement? Is it actually superior to regular cement in terms of strength?
Barge cement has a higher final strength than regular cement, but the strength development is slower. Here are some key performance notes:
– Compressive strength – The 28-day compressive strength is higher for barge cement, typically around 60 MPa versus 40 MPa for regular cement.
– Slower early strength gain – Due to the lower hydration temperature and water reducers, barge cement gains strength more slowly at 7 days. This means it requires careful curing.
– Better long-term strength – With proper curing, the long-term strength (1+ years) is improved vs. regular cement. The additions make it more durable.
– More resistance to corrosion – The lower permeability and chlorine binding capacity give barge cement better corrosion resistance.
– Less susceptible to damage from water – Considering its specialized blending, barge cement holds up better when exposed to flowing water or wet conditions over years of service.
So while barge cement may gain strength slower initially, its long-term strength and durability is superior, particularly when used in the wet environments it was designed for. Proper curing is critical to allow full strength development.
Typical composition
To understand the performance benefits of barge cement, let’s take a look at how it differs from standard Portland cement in its composition:
| Component | Regular cement | Barge cement |
| Clinker | 75-85% | 40-65% |
| Blast furnace slag | 0-5% | 20-60% |
| Fly ash | 0-5% | 0-10% |
| Calcium sulfate | 2-10% | 2-10% |
| Other | Water reducers, corrosion inhibitors |
Key differences:
– Lower clinker ratio – Less calcium aluminates to avoid early stiffening
– Higher slag content – Improves water-resistance and strength
– Use of additives – Water reducers and corrosion inhibitors enhance performance
So a specialized composition allows barge cement to have superior strength and durability in watery environments versus regular cement.
Production process
In addition to a unique composition, barge cement undergoes some differences in its production process:
– Tighter control of raw materials – Chemical composition is controlled to precise specifications
– Separate grinding – Raw materials are ground separately to achieve optimal particle size
– Lower temperature clinkering – Done at 1350-1450°C versus 1450°C for regular cement
– Ball mill grinding – The clinker nodules are finely ground to maximize reactivity
– Blending – Ground clinker is blended with the slag, fly ash and chemical additives
– Quality assurance testing – Extensive testing verifies water-resistance and strength gain behaviors
So barge cement is not only blended differently, but the production process is tailored to develop a consistent product with the desired qualities. Tight control over composition and processing is required.
Standards
There are a few main standards that define the specifications and testing procedures for barge cement:
– EN 197-1 – Defines cement types including Portland-slag CEM II/A-S and Portland-fly ash CEM II/B-V, the primary standards for barge cement in Europe
– ASTM C595 – Defines Type IS(<70% slag), Type IP (<25% slag), Type IL (<10% slag) barge cements in the USA - GB/T 18046 - Chinese standard defining barge cement composition and properties - JIS R5211 - Japanese standard with specifications on barge cement The standards help ensure quality control and uniform performance. Specifiers can select the appropriate type of barge cement for their project needs based on these standards.
Cost comparison
A key consideration with barge cement is cost. The specialized production and tighter quality control means barge cement tends to cost more than general use cement. Here are some typical price differences:
– Barge cement – $120-$150 per ton
– Regular cement – $90-$110 per ton
So barge cement can cost 25-40% more than regular cement. However, considering the superior durability and longevity in watery environments, it is cost-effective for the right applications.
Life-cycle cost analysis should be done to evaluate the best value. The higher upfront cost of barge cement may be justified by a longer service life and lower maintenance requirements when used in the proper setting.
Environmental impact
Barge cement also has some favorable environmental qualities relative to regular cement:
– Lower clinker ratio – Less limestone/clay needs to be kilned into clinker, reducing emissions and energy use
– Higher slag content – The use of blast furnace slag waste product reduces landfilling needs
– Less permeability – Lower seepage means less impact on surrounding water bodies
– Lower carbon footprint – Estimated at 20-40% lower CO2 emissions per ton depending on composition
So while concrete in general has high embodied carbon, the production process and composition of barge cement helps reduce its environmental impact compared to regular cement.
Conclusion
In summary, barge cement is specially engineered to provide superior strength and durability in watery environments through its unique composition and tight production controls. It gains strength slower initially but has better long-term resistance to water permeation, erosion, and corrosion. While it costs more upfront than regular cement, for the right applications its longevity and performance justifies the additional cost. It also has some sustainability benefits from its mix design. Understanding the differences of barge cement allows it to be specified selectively when regular cement may not suffice.