The rapid growth in the use of concrete as a construction material, not just for buildings, but for many other applications such as decorative objects, furniture, jewellery and art, is due in part to its increasing flexibility. It is the world’s most widely used construction material and over 10 billion tons are produced each year.
According to a report carried out by Market Research Future1 , the global ready-mix concrete market is expected to grow by a CAGR of over 8% from 2017 to 2023.
The development of chemical and mineral admixtures has had a huge influence on the modification of concrete properties, both pre and during production, giving it more versatility and some amazing new features. Available in liquid or powder form, these chemical components basically give concrete a range of superpowers.
Concrete admixtures can improve concrete quality, strength, durability and workability. Admixtures are used to overcome difficult build situations, such as extreme temperatures or pumping requirements and accelerate or slow down concrete setting time.
Here is a snapshot of the most common uses for admixtures.
These are used to reduce concrete setting time which in turn increases the rate of concrete strength development. This is particularly useful in cold weather.
Used to slow down hydration which slows the rate of setting and keeps the concrete workable, it is particularly useful in hot weather when there can be a faster initial setting rate. This type of admixture is useful for mortars and screeds.
Air entrainment agents create microscopic bubbles of air distributed uniformly throughout the concrete matrix, this increases cohesion and resistance to freeze-thaw degradation. It also helps to reduce bleeding and segregation of the fresh concrete and improves durability and resistance to wetting and drying.
These additives can reduce the water content necessary to reach a required workability and is often used to obtain specific concrete strength using lower cement contents, this results in lower CO2 emissions and energy usage.
Additives are added at the initial mixing to reduce early or long-term drying shrinkage in situations where shrinkage cracking could lead to durability issues.
This family of additives essentially improve the workability of the concrete. The additives help produce flowing concrete with a high slump used in heavily reinforced structures.
There is also a range of speciality admixtures that can do things like change the colour of concrete, make it luminous or waterproof.
Corrosion-inhibiting additives can reduce the corrosion rate of reinforcing steel in the concrete and therefore help to reduce maintenance costs of the structures. Typical uses would be in marine and bridge construction.
Fibres can be both micro synthetic, macro synthetic and alkali resistant glass fibre. Oscrete hold a good range of both technologies and can advise on the correct fibre for the right application.
Continuing research is sure to bring further new and exciting additives onto the market. Oscrete are specialists in the UK construction chemicals industry and can help with advice and information on getting the best results from these game-changing products that take an ancient construction material way into the future.