Civil Engineering May 2021 | Vol 29 No 4

I n Br i ef Global shortages erode cement and concrete additive supplies South African concrete and cement addi- tive suppliers are under severe production pressures due to the global shortage of many primary chemical industry raw materials essential to produce concrete and cement admixtures, says Norman Seymore, CEO of the CHRYSO Southern Africa Group and Vice-president of CHRYSO internationally. Admixtures and additives play a vital role in enhancing concrete performance in terms of strength, durability, material costs, as well as general site productivity. “This crippling shortage of vital raw materials will not resolve itself overnight. In fact, we fear that the supply and cost constraints are expected to continue for the foreseeable future,” warns Seymore. He says the severe shortage of raw materials is caused by a combination of several factors, including: Q Q Extremely cold weather conditions in the USA in February this year, which caused production interruptions and force majeure setbacks for many players in the petrochemical industry. Q Q A severe industrial accident at a major chemical company in Europe which led to a chain of force majeure declara- tions, slowdowns, and even shutdowns of several chemical production units. Q Q Scheduled maintenance shutdowns of several key chemical production units throughout the world which nega- tively impacted global raw material production capacity. “The strong rebound in activity in several sectors of the global construction and ancillary industries since the beginning of 2021 has generated strong demand for key raw materials. “The current raw material cost surge has no connection to the usual market indicators and mechanisms. CHRYSO is currently experiencing the consequences of this strong imbalance between supply and demand at a global level. However, we are doing everything possible to maintain continuity of supply of our products. But the situation will take some time to resolve and cost constraints are expected to continue for the foreseeable future,” Seymore adds.  CHRYSO's head office in Jet Park, Johannesburg Sika demonstrates waterproofing excellence Highlighting the waterproofing excel- lence of Sika products, that company’s Cemflex® product was recently used in a koi pond application. Johannes Brand, from the Sika team in Botswana, teamed up with Christiaan Bothma from Whistle PTY LTD to es- tablish the ideal long-term waterproofing solution for a residential koi pond project. Sika® Cemflex®, a universal water- proofer and bonding agent, was specified for the koi pond. It offered a practical and durable submersible waterproofing solu- tion for the pond walls and floor. When mixed with Portland cement and water, the product forms an effective water- proofing slurry that is used in conjunction with the Sika® Cemflex membrane. This waterproofing system is ideal for reser- voirs, shower floors and walls, veranda floors, ponds and retaining walls. It is watertight, non-toxic and UV stable. The surfaces on which the water- proofing products were applied were all raw reinforced block work. Provided that the correct preparations are implemented – such as mixing ratios and readying pre-cut membrane for application – this system is very simple to apply on such surfaces. Cement is highly alkaline and will initially influence the pH of the water. Given the sensitivity of koi to the quality of their environment, it is important to thoroughly wash out the pond after applying the Sika® Cemflex® slurry. Conveniently, and unlike bitumen waterproofing systems, the Sika® Cemflex® waterproofing system requires no waiting period before the pond can be filled. Sika® Cemflex® is technically and aesthetically an excellent product in providing a durable, seamless, and professional waterproofing solution. Immaculately built, this koi pond added the perfect touch to this home, bringing life to its surroundings and joy to the proud owners – proof that Sika’s depend- ability is indeed watertight.  42 May 2021 Civil Engineering The completed koi pond