iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Blended cement can cut emissions by replacing some of the clinker in ordinary cement with other binding materials. That matters because making clinker releases carbon dioxide both when fuel heats the kiln and when limestone is chemically transformed. The idea of combining materials has ancient roots, but Roman concrete was not modern Portland blended cement. In London, the Shard’s foundation mix shows how a modern blend can serve both environmental and engineering goals.
Why cement’s clinker content matters for climate
Cement is the binder in concrete, and clinker is its key energy- and emissions-intensive ingredient. Producing clinker requires high kiln temperatures, which involve fuel-related emissions. It also releases process emissions when limestone is calcined—chemically transformed to make clinker. Replacing some clinker can therefore reduce both sources of emissions associated with making cement.
The United Nations Environment Programme (UNEP) says cement and concrete production together account for around 8% of global CO₂ emissions. It also reports that buildings and construction account for 34% of global energy-related CO₂ emissions, citing the Global Status Report for Buildings and Construction. Those figures describe related but different scopes: the first covers cement and concrete production; the second covers energy-related emissions from buildings and construction.
Recommended Free Tools
Construction materials are consequential in part because demand is expected to keep growing. UNEP reports that around half of the buildings expected to exist in 2050 have yet to be built. Reducing the impact of new construction materials is one part of addressing that future demand, alongside using fewer materials where possible, extending building life and increasing reuse.
#1 Best Overall
- 【750W High-Performance Copper Motor】 Powered by a robust 750W (1HP) copper-core motor, the SILVEL wheelbarrow-style concrete mixer operates at 30 RPM for fast and thorough mixing. Ideal for heavy-duty commercial use and versatile enough for agricultural applications—such as seed inoculation and feed blending—it delivers reliable, consistent performance across a variety of tasks.
- 【Large 5.3 Cu.Ft. Mixing Capacity】 With a spacious 5.3 cubicfoot drum, this cement mixer handles large batches with ease.Perfect for construction sites and bulk agricultural mixing, itreduces the need for repeated refills, saving time and improvingoverall workflow efficiency.
- 【Rugged, Long-Lasting Build】 The drum is made of thick and high-strength steel, which is resistant to pressure, cracking and rust. It is easy to clean after use. It is equipped with a reinforced steel frame and treated with corrosion-resistant powder coating. This blender can exhibit outstanding durability even in the most demanding environments.
- 【Portable Wheelbarrow-Style Design】 Designed for easy mobility, this mixer moves effortlessly between job sites like a wheelbarrow. Navigate smoothly across yards, construction grounds, and farms without strenuous lifting—bringing mixing power exactly where it’s needed to maximize productivity.
- 【Easy Assembly & Dedicated Support】 Comes with all necessary hardware and clear instructions for quick setup. Should you need assistance, our responsive technical support team is available to help you get started and keep your projects running smoothly.
What blended cement is—and what can go into it
Blended cement contains clinker combined with one or more supplementary cementitious materials (SCMs). Depending on the blend and what is available locally, these can include fly ash, slag, natural pozzolans, calcined clay and limestone. The components can contribute to binding performance in different ways; they are not interchangeable in every recipe or application.
UNEP says blended cements available today can produce up to 50% fewer emissions per tonne than ordinary Portland cement while delivering comparable strength, durability and cost. That is an upper-end figure, not a guaranteed reduction for every blend. Actual results depend on the particular materials and mix, so a project needs a verified emissions figure for the cement it specifies rather than assuming that any product labelled “blended” achieves the maximum.
Rank #2
- 1. High-Performance Spiral Mixer Paddle Design---Our Paint Mixer for Drill features a specialized 4-blade spiral spiral head that functions as a high-speed mixer paddle . This heavy-duty drill attachment creates a powerful vortex to blend paint from the bottom up, ensuring a consistent, bubble-free mixture every time.
- 2. 15.75" Long Paint Stirrer for 1-5 Gallon Buckets---At 15.75 inches long , this extra-long paint stirrer is the perfect 5 gallon bucket mixer . The extended reach ensures your power drill chuck stays clean and away from splashes, while the 3.15" diameter head provides maximum coverage for containers ranging from 1 gallon to 5 gallon pails .
- 3. Universal Hex Shank Drill Attachment---Equipped with a standard hex shank. This universal drill mixer attachment transforms your handheld power tool into a professional mortar, mud, and grout stirrer , offering a slip-free connection for high-torque mixing tasks.
- 4. Rust-Proof Zinc Plated Steel Design---Built with reinforced zinc-plated steel , our metal mixer paddle is rust-proof and corrosion-resistant. This heavy-duty stirrer is designed for the rigors , automotive repair, and woodworking work, ensuring it won't bend or break under the pressure of thick materials.
- 5. Splash-Free & Easy to Clean Stirring Tool---The splash-free geometry of this stirrer for drill keeps your workspace pristine. Designed for easy cleaning , simply rinse the mixer bit in a bucket of water or wipe it down after use. Ideal for home decor, thinset, concrete, plaster, and cement mixing , making it addition to your DIY tool kit .
LC3 and multi-component blends
One prominent family is limestone calcined clay cement (LC3), which combines limestone and calcined clay with cement components. UNEP reports that LC3 could reduce cement-production CO₂ emissions by up to 40% compared with traditional cement while maintaining required construction performance. This is a reported potential, not a result that should be assigned automatically to every LC3 product or project.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
In the UK, The Concrete Centre says BS 8500:2023 incorporates multi-component cements defined in BS EN 197-5:2021. Under those cement types, two or more SCMs can replace up to 65% of Portland cement. This is a standards-based allowance for specified cement types, not blanket permission for any recipe or use: the relevant concrete specification, application and project requirements still govern suitability.
Rank #3
- CEMENT NOT INCLEDED
What Roman concrete has to do with modern blends
Roman concrete, or opus caementicium, combined lime mortar with volcanic ash known as pozzolana. The Pantheon is a notable surviving example of Roman concrete’s longevity and structural ambition. The historical connection is the broad principle of combining materials to obtain useful binder properties.
That does not make Roman concrete Portland cement. It used different chemistry and materials, and it was not made with today’s clinker-replacement recipes or governed by modern cement and concrete standards. The comparison is a useful reminder that blended binders are not a wholly new idea, not proof that ancient and modern materials are equivalent.
How the Shard’s foundation blend served an engineering need
UNEP reports that the Shard’s extensive foundations used a cement blend containing 70% ground granulated blast-furnace slag (GGBS). In large foundation elements, reducing early heat as the concrete cures helped manage thermal stresses. This project-specific example shows that a blend can be selected for engineering performance as well as for its potential to lower emissions; it does not establish that the same mix is suitable for every foundation or structure.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →UNEP also cites high-performance mixes used in the Burj Khalifa and One World Trade Center. These examples illustrate that blended materials can be part of demanding construction, but they do not substitute for checking the properties and requirements of a particular project.
Best Value
- 【Strong Power】 SILVEL concrete mixer machine is equipped with a 450W copper motor (horsepower: 3/5HP). The mixer operates at a speed of 28RPM for efficient and fast mixing.
- 【360° Turning＆Mixing】This cement mixer machine has a spring-loaded disc tilting wheel which is very easy to operate and can freely flip and 360° mixing. It has the features of even mixing, short time consuming, easy cleaning, etc.
- 【High Quality Material】The electric cement mixer machine is made of heavy-duty steel with a durable powder-coated finish that resists rust and corrosion. The toothed ring is made of cast iron for extra durability and long-lasting use.
- 【Easy to Move】Our portable concrete mixer machine has a very user-friendly design with two large 7*2" solid wheels and handles that make it very easy to move around. Also the triangular structure design makes the blender more stable to stand.
- 【Multi Occasion Use】Cement mixer macine has a large capacity of 120L 4.3 cu. ft and can handle mortar, grout, or concrete, and can be used not only for commercial purposes, but is also great for agricultural uses, such as mixing seeds and feed.
What determines whether a blend is right for a project
There is no single best blend for every building. A designer or specifier needs to consider the whole mix and the conditions it must meet, not just the proportion of clinker displaced.
- Verified emissions per tonne: Compare product-specific emissions information and clinker replacement rather than treating the maximum reductions reported for some blends as universal.
- Strength and durability: Confirm performance for the structural use and exposure conditions the concrete will face.
- Setting and early heat: Check whether the mix’s heat development and setting behaviour suit the element, construction sequence and thermal-control needs.
- Standards and specification: Establish that the cement and concrete meet the applicable standards and project requirements. A permitted cement type does not make every mix suitable for every application.
- Supply and consistency: Confirm that the chosen SCMs can be sourced reliably and consistently where the project is being built.
Why wider adoption is not just a mix-design decision
Standards, building codes and procurement practices influence which lower-carbon cements can be specified and used at scale. Supply matters too. The UK government says established SCMs such as fly ash and GGBS are becoming less available. A 2025 review of the UK cement industry also describes declining availability associated with phase-downs in coal generation and changes in steelmaking—the industries that supply conventional by-products used in some blends.
That constraint strengthens the case for developing and qualifying other SCMs, but it does not mean every alternative is impact-free, widely available or appropriate for every use. Responsible selection depends on reliable supply and performance evidence as well as emissions claims.
Free tools Windows power users keep installed
One-click scans. No signup required.
Blended cement is one part of lower-impact construction
UNEP’s wider point is that decarbonising buildings means looking across their life cycle, not relying on a single material change. As Gulnara Roll, Head of GlobalABC at UNEP, puts it: “All materials have a role to play, and all materials need to reduce their environmental impact.” She also points to using fewer materials where possible, extending the life of existing buildings, increasing reuse and circularity, and responsibly sourcing local, bio-based and other low-carbon materials. Blended cement is one part of that broader transition.
Replacing some clinker can reduce cement-production emissions while still meeting construction needs, but the benefit depends on the actual blend, its supply and its verified performance. Roman concrete offers a historical parallel in combining materials; the Shard illustrates a modern, project-specific use. Neither makes blended cement a one-size-fits-all solution.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
