Using admixtures to tailor-make concrete for your project

Admixtures for concrete

Concrete is a highly versatile building material. It can be tailor-made to suit the specific requirements of the contractor, simply by adding certain chemicals. These admixtures can speed up the setting of concrete, trap more air or absorb the water inside the concrete structure.

Admixtures can help to improve the workability and performance of concrete, depending on the type of structure being built and its environment. This improves the versatility of this popular building material. Admixtures offer many benefits for contractors, so researchers are always looking at new types of admixtures that will improve concrete mixes.

What are researchers looking to improve?

In particular, researchers are exploring ways to make concrete more sustainable by sourcing local materials. This reduces the carbon emissions needed for transport of the raw materials. Admixtures help this local sourcing to be a viable solution for cement manufacturers and suppliers.

Research and development teams have studied the properties of concrete that give it strength and durability. The aim is to see how these molecules behave and how they can be manipulated by admixtures to improve performance, especially when it comes to harsh environmental conditions such as floods and earthquakes.

These international research teams are examining how admixtures, such as volcanic ash, can enhance the frictional forces between cement particles. Using local admixtures can further improve the suitability of concrete to local environmental conditions.

The most common admixtures

It is common for contractors to use admixtures in concrete batches. Each additive has a different effect on the concrete. Here are five of the most common admixtures and what they do to concrete mixes:

1. Accelerating admixtures

Accelerating admixtures speed up the early strength development of the concrete batch. This reduces the curing time and accelerates the time for construction. Accelerating admixtures are useful in winter when the cold weather slows down the time for setting and curing of concrete.

2. Retarding admixtures

Retarding admixtures are the opposite of accelerating ones – they slow down the rate of setting and curing of concrete. This makes concrete more workable in hot weather, where the heat makes the concrete set quickly.

3. Air-entrainment admixtures

Air-entrainment admixtures help to trap air in the concrete. This improves the workability of concrete and helps to reduce water-bleeding and segregation. The microscopic air bubbles also help to prevent internal cracking that sometimes occurs when the water in the concrete freezes in cold temperatures.

4. Water-reducing admixtures

Water-reducing admixtures reduce the amount of water needed for a concrete mix. This additive will lower the water-to-cement ratio, which makes the concrete batch more economical in water-scarce regions. These admixtures also enable contractors to increase the strength of concrete without the need for more cement, making it more affordable.

5. Superplasticisers

Superplasticisers, also known as high-range water reducers, drastically reduce the water content of a concrete batch – more than water-reducing admixtures. Superplasticisers create a high-slump, flowing concrete batch which improves workability and reduces the need for compaction.

___

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 cement brand for over 30 years. Our head office and fully-integrated plant are located in Mbeya, 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 new 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, LinkedIn and Pinterest for the best tips on construction, handy projects and the latest industry news. See our Instagram channel for more insights into our products.

What to do with leftover concrete blocks

Repurposed concrete blocks

If you have leftover concrete blocks from a construction project, don’t throw them away. These building materials have many creative uses in the home, from creating benches to becoming pots for plants. Concrete blocks are a versatile and durable product that lend themselves to many uses.

If you don’t have leftover concrete blocks but still want to try some of these projects, you can easily make some soil-stabilised bricks yourself. Or, you can use Tembo cement and TemboFundi to create your own concrete blocks. Here are a few ways to repurpose concrete blocks in the home.

Use concrete blocks to make shelves

Whether you need to create space for some books or want some extra storage room, concrete blocks are ideal for making quick and easy shelves. You’ll need some extra timber to form the actual shelves and the concrete blocks will form the solid support.

To make the shelves, use two upright concrete blocks as the base, as wide apart as the lengths of timber. Place a piece of timber across the top of the concrete blocks. Put another two concrete blocks on top of the piece of wood and repeat this process of building simple shelves.

The weight of the concrete blocks will keep the wooden shelves secure. Make sure that you build the shelves on a perfectly level floor otherwise they may fall over. Three or four layers of blocks should be ideal for a sturdy set of shelves for books, tools and papers. You can make the shelves in the home, an office, a garage or outside.  

Make a bench seat from concrete blocks

Like a set of shelves, all you need to make a bench seat is some concrete blocks and timber. To make the bench, start by placing eight concrete blocks upright on the ground – four on each side of the bench. If you’re building the bench outside, you may want to dig a small hole to secure the blocks in the soil and make them perfectly level.

Place another two concrete blocks horizontally on top of the four base blocks, repeat for the other side of the bench. Next, slot your timber through the holes in the top layer of blocks, joining the two sides of the bench. There should be four holes on the top layer of blocks, so you’ll need four pieces of wood.

If you have spare cushions or pillows, place them on top of the wooden slats for added comfort. If you build the bench against a wall, you can use the wall as a backrest. This type of bench can be made inside or outside and it costs next to nothing to build. You can even build a bench in a square around a fireplace.

Use concrete blocks as pots for plants

Concrete blocks make the perfect pots for plants – the two holes in each block can be filled with gravel, soil and mulch. Even half-block can be used as a single pot. Contractors often leave half-blocks after a project, so you may have more of these lying around.

Place the concrete blocks on the ground so that the holes point vertically. Put a layer of small crushed stones at the bottom of each hole to help with drainage. Next, fill the hole with soil and plant some herbs, smalls vegetables or flowers. Add a layer of mulch on top of the soil for added moisture retention.

Remember to water the plants often and put the concrete blocks in an area with enough sunlight. You can also stack the blocks to create a garden feature or wall of plants. The blocks can also be painted to match the colour of the house or to stand out in the garden.

Make an outdoor table or countertop

You can use old concrete blocks to build a useful outdoor table or countertop. This project does require some building knowledge and cement skills. You’ll need some cement to create the four pillars (or legs) of the table.

Mix a batch of concrete using Tembo cement, sand and water. Dig a small hole in the soil for each concrete pillar and pour in a layer of concrete to make the foundations. Let the concrete dry for two days. Then, build the four pillars using concrete blocks and cement. The pillars can be four or five blocks high, or about 1,5m tall. Let the concrete cure for two weeks.

Use some lengths of wood and attach them to the top of the four pillars using 90-degree brackets and some screws. The wooden top makes a great surface for the table or countertop and is ideally suited for outdoor use.

If you have any concrete blocks left over from a building project, make use of these ideas to create some useful furniture or features for your home. There are many ways to repurpose concrete blocks, it just takes some creative thinking.

___

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 cement brand for over 30 years. Our head office and fully-integrated plant are located in Mbeya, 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 new 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, LinkedIn and Pinterest for the best tips on construction, handy projects and the latest industry news. See our Instagram channel for more insights into our products.

LafargeHolcim Tanzania staff interview – Christian Mvula

LafargeHolcim Tanzania employee Christian Mvula

LafargeHolcim Tanzania empowers and provides employment opportunities for local citizens. One of our priorities is to develop talent and strengthen the Tanzanian economy through the building materials and cement industry. By harnessing opportunities and uplifting Tanzanians, LafargeHolcim is actively supporting the growth of the country.

Christian Mvula is a valued employee at LafargeHolcim Tanzania. Listen to what he has to say:

By developing local talent, LafargeHolcim Tanzania establishes itself as a leader in the industry and is able to produce quality products. Our Tembo cement products are versatile and durable. We aim to improve the careers and lives of all Tanzanians; those who join our team and those who use our Tembo products.

___

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 cement brand for over 30 years. Our head office and fully-integrated plant are located in Mbeya, 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 new 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, LinkedIn and Pinterest for the best tips on construction, handy projects and the latest industry news. See our Instagram channel for more insights into our products.