Importance of pouring concrete at the right temperature

Pouring concrete in hot temperatures

Extreme heat or cold weather can have a significant impact on the quality of freshly-poured concrete. In Tanzania, temperatures are usually hot; even in winter it rarely reaches single-digit temperatures. Therefore, it is important to time construction projects right so that temperatures are not too warm when pouring concrete.

Cooler temperatures slow the curing process down and ensure that the concrete reaches its optimal strength before drying out. The structural bonds that give concrete its strength take time, so if it dries too quickly, the concrete will become brittle and more prone to cracks.

The ideal temperature range for pouring concrete is between 10°C and 32°C – the sort of temperatures often found in Tanzania. However, during hot summers, there are ways to improve concrete quality when pouring in hot conditions, including using the right equipment and techniques to keep the concrete at a lower temperature.

Tips on pouring concrete when it’s hot

Concrete that is poured in hot weather will have a high early strength but the final quality will be substandard. With proper planning and the right tools, you can pour concrete in hot weather using the following techniques:

  • Hire sufficient contractors and have enough equipment to reduce the time between the start of pouring and the completion of the curing process.
  • Plan to pour the concrete early in the morning or late in the evening when temperatures are cooler.
  • Put up shade cloth over the freshly-poured concrete to keep it out of direct sunlight. Place windbreaks around the construction site to reduce the effects of wind evaporation.
  • Keep the concrete damp by spraying water over its surface or use a damp covering fabric such as wet burlap.
  • Prolonged mixing increases the temperature of concrete so pour it as soon as it’s ready.
  • Spray water on concrete forms (wooden frames) and loosen them once the concrete has just set. Pour water down the sides of the forms too.
  • Use larger aggregates in the concrete as these prevent it from shrinking due to heat and water evaporation. Spray the pile of aggregates with water before adding them to the concrete mix as this will cool them down.
  • Keep conveyors, wheelbarrows, chutes and concrete-carrying equipment under the shade if possible. Spray water on them to reduce their temperature.
  • Spray the ground with water to keep it moist and cool before pouring in the concrete.

Construction projects are best planned for the cooler months when temperatures are lower and there is less likelihood of rain. The concrete pouring phase should ideally take place when the annual temperatures are at their lowest – often between June and August in Tanzania.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

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LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

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At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter, LinkedIn and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

LafargeHolcim Tanzania value-added services

LafargeHolcim Tanzania value added container services

LafargeHolcim Tanzania offers a number of value-added services on top of our range of cement products. These services are specific to a client’s needs and requirements, ensuring that they get the maximum benefit from their investment.

Here are some of the value-added services that we offer:

  • Cement in bulk trucks – Certain customers require large amounts of cement for their construction projects. Instead of supplying bags of Tembo cement, we can deliver the product in a bulk truck. This delivery method is perfect for large construction projects, where bulk cement is needed on a regular basis.
  • Cement silos –  LafargeHolcim Tanzania can supply bulk silos for the storage of cement products, allowing clients to access the product as and when they need it, depending on your project requirements.
  • Containers for storage – We can supply large containers that act as the perfect storage facility for your Tembo cement bags. 

LafargeHolcim Tanzania also offers cement mix design support and technical training for our customers.

Depending on your needs and requirements, LafargeHolcim Tanzania can arrange these convenient value-added services so you can focus on your project.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter, LinkedIn and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

The importance of concrete curing

Workers pouring and curing concrete

Concrete curing is the process of keeping freshly-poured concrete from drying too quickly. It determines the final strength and quality of the construction.

Concrete actually needs moisture to set, especially when a hydraulic cement is used in the mix. The right moisture conditions, temperature and time are essential for a strong concrete – it enables the concrete to gain more strength over time.

The curing time is dependent on the concrete mix – too watery and the concrete will take too long to set; too dry and the concrete will set prematurely, shrink and become brittle. Time is needed for strong bonds to form between the cement and aggregates.

As concrete dries, moisture rises to the surface. If this moisture evaporates too quickly, the concrete can shrink and crack. If it doesn’t cure properly, concrete can develop weak qualities similar to chalk – it can crumble and become dusty. Here’s how to ensure you cure concrete properly to create a strong and durable structure.

How to cure concrete properly

There are numerous ways to cure concrete correctly. Regardless of the method you choose, it is important to leave the concrete forms in place long enough to keep the moisture in and prevent it from drying too quickly.

  • Water curing – This method involves flooding or misting the surface of the concrete with water. It’s common to see construction workers hosing down concrete. Water curing is an easy and effective method that keeps vital moisture in the concrete until strong bonds are formed.
  • Water retaining – This method uses damp coverings such as river sand, straw, canvas or woven sacks. These materials are kept wet during the curing process and are better suited in extreme temperature environments; in hot climates, the damp covering is less susceptible to evaporation than surface water; in cold climates, the covering prevents water from freezing and cracking the concrete.
  • Waterproofing – This method uses waterproof plastic or paper on the surface of the semi-dry concrete. Once the concrete is hard enough to resist surface damage, a plastic covering can be applied to keep remaining moisture in. This method can cause discolouration of the concrete, so it should not be used if the appearance of the concrete is important.
  • Curing chemicals – This method entails adding chemicals to the concrete as soon as it has been poured. Curing chemicals, such as oils or soluble waxy emulsions, can be sprayed onto the surface of concrete and left for a few weeks. They will naturally break down when exposed to sunlight, and some chemicals can make the concrete slippery, so avoid using on surfaces where grip is important.

How long does the curing process take?

Ideally, a concrete slab should be kept moist and warm for the first month after pouring. The first week is the most important, so if deadlines are approaching and time is short, keep the concrete moist and between the temperatures of 10 and 32 degrees Celcius for the first seven days.

Concrete only reaches its full strength after 28 days. The longer you allow it to cure under the correct moisture and temperature conditions, the stronger it will become. This strength, often called concrete cylinder strength, is important for large buildings and surfaces that will be put under a lot of weight, such as industrial floors and foundations.

The difference between concrete curing and setting

Concrete is set when it is hard enough to support some weight without being damaged – typically after three days. This means you can walk on it without leaving footprints. Concrete is cured when it has reached its full strength and can support all the weight that it was designed for – typically after 28 days.

Depending on environmental conditions, concrete can set and cure in different amounts of time. Like curing, the setting time is dependent on the concrete mix and external environmental factors such as temperature and moisture.

In some hot climates, concrete can set within two hours of being poured but in cold climates, it can take a number of days. If temperatures are below freezing, concrete may not set at all. The curing time follows the same logic.

Using the right concrete mix in the right environmental conditions is important for a strong structure. The curing time directly determines the strength of concrete, so be sure to allow the concrete to cure properly before placing heavy loads on the surface.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter, LinkedIn and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

Make your own concrete vases

Make your own concrete vases

Who doesn’t like to get a little creative on the weekends and tackle some homemade projects? Using one bag of Tembo cement, some sand and water, here are some fun and easy concrete vases that you can create using old bottles.

Tembo cement is a versatile product that is perfect for home-based projects such as these. Just remember to strain the wet concrete mixture through a mesh to remove larger pieces of gravel if your concrete contains any. For intricate and detailed projects, you’ll want a smooth concrete mix with no big stones or lumps.

Get creative with Tembo – make your own concrete vases

  • Tembo cement, fine sand, water
  • Old bottles (preferably plastic)
  • A pen or a glass test tube
  • Craft knife (or wire cutters)
  • Drill (cordless if you have one)

Steps to making concrete vases

  1. First, drill a hole in the cap of the plastic bottle using the drill. Stick the pen or the test tube into the hole and push it about 10cm through – this will form the cavity of the vase.
  2. Cut off the bottom of the plastic bottle using the craft knife. If you only have glass bottles, leave them intact but use a little more water in the concrete mix.
  3. Prepare your concrete by mixing Tembo cement with fine sand and water. Follow the directions on the packaging if you need guidance.
  4. For plastic bottles, place the cap and test tube back on the bottle and turn it upside down. Fill the bottle with the concrete mix, pouring it in from the open bottom. Tap the sides of the bottle to remove trapped air and keep topping up the bottle with concrete. For glass bottles, carefully pour in the concrete mix through the top. Place the pen or test tube into the wet mix and allow it to set.
  5. Leave the concrete to set for at least 20 hours. The longer the better.
  6. Once the concrete has hardened, cut away the plastic bottle using the craft knife. For glass bottles, cover them with an old shirt and hit gently with a hammer to chip away the glass from the concrete.
  7. Cut off the top of the test tube or pen using the wire cutters or craft knife.
  8. File down any rough edges and exposed bits of glass test tube or plastic pen.

These homemade vases will have a rustic look. Visible air bubbles and jagged edges can also add to the charm of the vases, so don’t worry about being a perfectionist when filing down the edges.

Original source: www.homemade-modern.com

To read this article in Swahili click here.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter, LinkedIn and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

The difference between cement and concrete

Difference between cement and concrete

The terms ‘cement’ and ‘concrete’ are often used interchangeably but they aren’t actually the same thing. The major difference is that cement is the grey powder that is mixed with sand, stone and water to create concrete – cement is an ingredient of concrete.

Cement has been used as a binder of materials for centuries, stemming from other binding elements such as clay and volcanic ash. The use of cement can be traced back to Ancient Macedonia (~800 BC) but it became highly popular and started to revolutionise building during the Roman Empire (from 27 BC onwards).

Cement made from lime and volcanic ash allowed the Romans to build huge structures such as the Pantheon and their aqueducts. Today, cement is made of a mixture of calcium, silicon, iron, aluminum and other chemical compounds. These dry chemicals come from sea shells, chalk, limestone, clay, silica sand, and iron ore.

Two types of cement

Cement comes in two forms; hydraulic and non-hydraulic. Hydraulic cement is that which needs water to start the chemical reaction that hardens the mixture. Hydraulic cement is water resistant once it has fully cured, and it can even harden under water.

Non-hydraulic cement is that which does not need water to set. It has a much longer drying time than hydraulic cement and is not water resistant. For these reasons, hydraulic cement is the binding agent of choice for the majority of builders and developers.

Cement is an ingredient of concrete

Concrete is simply a mix of cement, water and aggregates (or inert solid materials such as gravel, sand and recycled concrete). Aggregates make up about 70% of the concrete mixture and the type of aggregate used depends on the purpose of the concrete.

Cement makes up about 10% to 15% of the concrete mix and is what binds the ingredients of concrete together. When making concrete, the cement and water harden to bind the aggregates together. This hardening process continues for years, meaning that concrete gets harder as it gets older.

Concrete is extremely durable, fire resistant and does not require much maintenance, which is why it is one of the most-widely used man-made materials on the planet. It is used to build most roads, pavements, dams, bridges and large buildings.

How to tell if the concrete is properly mixed

Using the right ratios of cement, water and aggregate is key to mixing the perfect batch of concrete. The character of the concrete is determined by the cement/water paste. Not using enough cement/water paste means that the concrete will be rough and porous. Using too much cement/water paste will create a smooth concrete but it will be more brittle and susceptible to cracks.

A properly-portioned concrete mixture will have the right workability when pouring and the correct durability and strength for long-lasting applications. A good batch of concrete typically comprises 10% to 15% cement, 15% to 20% water and 60% to 75% aggregates.

To read this article in Swahili click here.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

Soil stabilised brick project for Tunduma youth

Soil stabilised brick project

LafargeHolcim Tanzania has partnered with the Songwe Regional Commissioner to pilot the soil stabilised brick and mason project for youth in Tunduma. This educational programme teaches young Tanzanians about soil stabilised bricks.

The attendees learned valuable skills that can be used after the training programme to access the job market and earn a living. The participants are also given business and entrepreneurship training, as well as health and safety advice to ensure that they can succeed with their newly-acquired skills.

Around 40 young Tanzanians attended the course and completed their training. They were able to build a fully-completed classroom during the course of the project, using soil stabilised bricks. After the course, the youth started their own soil stabilised brick projects where they make and sell their own products.

Some of the participants have secured jobs as masons for the Tunduma local government, creating specialised stone products for a range of applications. 

What is a soil stabilised brick?

A soil stabilised brick is a low-cost and environmentally-friendly building material. Soil and bricks have been fundamental building materials for millennia.

Mud tends to erode when it comes into contact with water and the downside of a burnt brick is that it requires a lot of energy to produce, whether in a wood-fired kiln or a factory furnace.

Soil stabilised brick is an energy-efficient alternative. These bricks simply use cement as the binding agent; cement and soil are mechanically compressed to form a building block. These bricks are also water resistant and strong enough to build large structures and homes.

Soil stabilised bricks are more affordable and quicker to produce, cutting down the costs of a construction project. 

To read this article in Swahili click here.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the best materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

Road safety for schools around Mbeya and Songwe

Road safety for school children in Mbeya

LafargeHolcim Tanzania’s headquarters and cement plant are based in Mbeya – and it’s a vital job provider for the local community and families. During the company’s health and safety week, LafargeHolcim Tanzania undertook the task of providing the schools with the necessary safety tools and road markings to allow scholars to cross the roads safely. 

The schools received signs for stopping the traffic while students cross the road at designated pedestrian crossings. The schools were also given reflective jackets that are to be worn by the traffic directors on duty.

The traffic directors were given training on road safety and how to use the traffic poles to signal the trucks to stop. The school children were taught how to cross the road safely and are actively encouraged to use the designated crossings at the schools.

Transporters and traffic police officers also attended training sessions and are acutely aware of the safety of the scholars on the roads in the area. LafargeHolcim Tanzania will continue to work alongside local law enforcement, transporters and schools to ensure the continued safety of the community in Mbeya.

To read this article in Swahili click here.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

LafargeHolcim Tanzania builds new road for community

New community road built by LafargeHolcim Tanzania

LafargeHolcim Tanzania cares about the community that lives and farms around its operations. We believe in investing in the local community and building a safe space for all who live near our operations.

A new road was constructed for the citizens that live nearby our operations, giving them a safe route to use. This concrete road was built by LafargeHolcim Tanzania as a safe passage for the people and their livestock, also freeing up the quarry road for the trucks and quarry equipment.

Local community leaders were invited to the opening of the new road in May 2018 where community members were also encouraged to make use the road as they please.

To read this article in Swahili click here.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement and aggregates for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities.

Research and Development

With the world’s first R&D centre for the construction industry situated in Lyon, France, LafargeHolcim has spent 141 million CHF to date on research and development. We have 240 engineers and technicians from all over the world that develop solutions for the construction industry.

This has enabled us to create some of the most innovative products, solutions and services in order to reduce construction costs and contribute to more affordable housing.

The R&D centre has also enabled LafargeHolcim to improve the energy-efficiency of buildings; improve the aesthetics and strength of unique, resilient structures; minimise our environmental footprint; provide the energy industry with new solutions; make cities and worksites healthier and more sustainable; and stay one step ahead by anticipating new trends and highlighting new technologies.

To read this article in Swahili click here.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement, aggregates and ready-mix concrete for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

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Follow us on Facebook, Twitter, Instagram and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities and the living environment.

Sustainability

Geocycle sustainability sign at LafargeHolcim Tanzania

Statistics show that by 2050, 70% of the world’s population will live in cities. At LafargeHolcim we seek to contribute to the sustainability of cities throughout the world. Our solutions allow for more compact housing while preserving the quality and durability associated with LafargeHolcim.

With our long term growth goals playing an integral part of our foundation, LafargeHolcim continues to innovate and invent sustainable solutions for our planet’s future. Working at the local community level, we are able to continue our goal of sustainable environmental protection.

LafargeHolcim Tanzania is using alternative fuels such as biomass and conducting water-conservation campaigns in order to benefit the local environment and the local community.

To read this article in Swahili click here.

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LafargeHolcim is a leading building materials and solutions company that has been operating in international markets for decades. We produce cement, aggregates and ready-mix concrete for construction projects, ranging from small affordable housing developments to large-scale infrastructure projects such as high-rise buildings, dams and bridges.

___

LafargeHolcim Tanzania has been supplying the country and neighbouring countries with our world-class Tembo brand for over 30 years. Our head office and fully-integrated plant are located in the Mbeya Region in Southwest Tanzania.

___

At LafargeHolcim Tanzania, we believe customers come first. We listen to your specific requirements to supply and develop the best solutions for your needs. As the leader in building materials, you can also rely on our cutting-edge research and development capabilities that have resulted in the finest materials for your construction projects, whether large or small.

___

Follow us on Facebook, Twitter, Instagram and Pinterest for the best tips on construction, handy DIY projects and the latest industry news. See our Instagram channel for more insights into our work with local communities and the living environment.