When ambient temperatures become very hot or cold, concrete users can struggle to achieve the required strength and workability – but there are admixtures for those challenges.

Patrick Flannigan, Technical Manager at CHRYSO Southern Africa, explains that high temperatures cause concrete to develop higher initial strength, but reduce the strength development over the long term. Very cold weather creates the opposite effect, causing lower strength gain initially but higher strength gain later.

When temperatures drop below 5°C, the slower hydration process could even cause extended bleeding. At temperatures lower than that, there is a risk that the water in the concrete will freeze. Water expands by 9% when it freezes, so it could even cause cracking if the concrete has not reached sufficient strength.

“To deal with very hot weather, customers use our CHRYSO® Tard range of plasticisers, which ensures enough open time,” he says. “This retarder slows down the hydration of cement by momentarily blocking the surface of the cement particles and delaying the time of initial setting.”

For cold weather, he recommends the CHRYSO® XEL range of chloride and non-chloride accelerators, which help with early strength gain of concrete. To deal with the risk of water freezing in the concrete, CHRYSO® Air helps by adding extra air to the mix. Instead of cracking the concrete, the freezing water will expand into the capillary openings that the air entrainer has created. These low temperatures are not that common in South Africa, but more relevant to higher elevated areas such as the Lesotho Highlands.

“Another form of extreme weather leading to challenges with concrete is heavy rainfall that causes flooding,” he says. “Protection of concrete in rainy conditions is of the utmost importance, as this will eliminate surface blemishes on exposed concrete areas.”

Flannigan explains that concrete that is in contact with standing or flowing water needs to be protected, especially in terms of its finish. “CHRYSO® Aquabeton is the ideal solution for concrete that needs to be placed underwater, and this allows concrete to be cast in standing or flowing water.”

Flannigan points out that CHRYSO’s solutions are driven not only by functionality but by a global commitment to sustainability. The company develops admixtures specially for certain types of cement and construction material. This allows a wider range of material to be sourced close to site, even if it is high in clay content, for example.

“This reduces the distances that material needs to be transported and therefore keeps vehicle carbon emissions to a minimum,” he says.


An innovative range of dust suppressants available from CHRYSO Southern Africa, continues to be a gamechanger in the mining and quarrying sectors, providing substantial benefits and enhancing operational efficiency.

Sealing a road with CHRYSO Eco Dust.
Sealing a road with CHRYSO Eco Dust.

CHRYSO Eco Dust has a proven track record as an indispensable tool for industries operating in dusty environments. Michelle Fick, BU Development Manager: Concrete Aesthetics and Key Accounts, at CHRYSO Southern Africa, says this range of dust suppressants offers a comprehensive approach to sealing and maintaining dirt roads, gravel pathways, and other dusty surfaces.

“One of the major advantages of CHRYSO Eco Dust is its cost effectiveness,” Fick says. “Compared to alternatives such as paving or tarred roads, implementing the CHRYSO Eco Dust solution leads to significant cost savings. This is particularly important for operations facing challenging economic times as there is immense value in reducing maintenance expenses while achieving optimal dust control.”

She explains that CHRYSO Eco Dust provides long lasting effects, ensuring that roads and surfaces remain dust-free for extended periods. This characteristic is crucial in industries where regular maintenance and constant dust suppression efforts are time consuming and costly. By reducing the frequency of reapplication, CHRYSO Eco Dust streamlines operations and minimises disruption to daily activities.

Another major advantage offered by CHRYSO Eco Dust is its eco-friendly nature. The product is designed to be environmentally sustainable, with low volatile organic compound (VOC) emissions and UV resistance. Industries, especially those subject to stringent health, safety, and environmental regulations, have welcomed CHRYSO Eco Dust as a viable solution to ensure compliance while minimising their ecological footprint.

Fick is quick to point out that CHRYSO Eco Dust has gained traction in mining and quarrying operations. “These industries, which are often located in environmentally sensitive areas, face increasing pressure to minimise dust emissions and their impact on surrounding communities. CHRYSO Eco Dust not only helps meet regulatory requirements but also significantly reduces fuel and water consumption and carbon dioxide emissions associated with traditional dust control methods, such as water tanker spraying. The result is a greener and more sustainable approach to dust suppression.”

Moreover, CHRYSO Eco Dust improves overall safety in dusty environments. By minimising dust particles in the air, visibility is enhanced thereby reducing the risk of accidents. The improved road gripping also enhances traction for vehicles, further contributing to safety and preventing potential mishaps.

CHRYSO Southern Africa’s commitment to providing a comprehensive solution extends beyond mining and quarrying. The versatile applications of CHRYSO Eco Dust have made it a preferred choice in cement plants, precast yards, building sites, farms, game reserves, rural airfields and other areas where dirt roads and dusty surfaces require sealing and maintenance. Even less developed residential areas and sandy football pitches can benefit from the long lasting effects of CHRYSO Eco Dust.


As demand for innovative concrete solutions has grown around Africa, CHRYSO Southern Africa has extended its footprint to get closer to customers with the products and services they need. 

Armand van Vuuren, commercial manager exports at CHRYSO Southern Africa.

According to Armand van Vuuren, commercial manager exports at CHRYSO Southern Africa, the company’s expansion strategy has been pursued for almost a dozen years – with great results. There are now distributors in a range of key markets including Angola, Botswana, Ghana, Mozambique, Nigeria, Zambia and Zimbabwe.

“We also have an established office in Nairobi, Kenya and are expanding into Tanzania,” explains van Vuuren. “Through our extensive presence across Southern, Central, East and West Africa, we supply not just the readymix and precast sectors, but also specific construction and infrastructure projects.”

The expertise and resources of CHRYSO Southern Africa’s distributors in these countries is supported by the technical team in Johannesburg, who can step in whenever necessary with the required specialised input. He emphasises that these partners are carefully chosen to act essentially as extensions of the company – delivering the same high level of service wherever their clients work. 

“Africa is an exciting continent, and this is where future economic growth is going to come from,” he says. According to the African Development Bank, the expected growth rates in West and Central Africa are expected to be 4,2% and 4,6% respectively in 2023, while East Africa will reach 5,5% in growth terms. 

Van Vuuren highlights the extent to which many countries have invested heavily in infrastructure in recent years – demanding large volumes of concrete for civil engineering projects. The construction work involved in the Decongestion Project for Zambia’s capital Lusaka, for instance, has changed the face of that city in a matter of years. 

“CHRYSO Southern Africa and our distributors have been working with a range of contractors and other businesses to ensure that their concrete meets the exacting specifications of the contract,” says van Vuuren. “Whether the application is bridges, dams, mining infrastructure or precast manufacturing, we continue to play a vital and growing role in Africa’s development.”

An important element of CHRYSO’s presence is the stock that is held by distributors in their respective regions – giving customers easy access to product as and when it is required. End-customers are provided with full site support from a technical perspective, including access to the specialist team in South Africa. 

“With our current momentum, we are planning to set up more of our own offices and production facilities in key regions, paving the way to serve larger and more complex requirements,” he says. “Africa’s leading countries have their plans in place for future development and, despite the occasional setbacks, they are on track for long term growth. CHRYSO Southern Africa is working with the concrete and construction industries of Africa to help make this happen.”

This strategy is bolstered by recent acquisitions by its parent company, Saint-Gobain, of companies such as GCP Applied Technologies that will offer access to innovations and new products. Firmly committed to customer centricity and proximity, the organisation has local operations in 45 countries and this footprint provides its service offering to more than 100 countries.