How Calcium Sulfoaluminate (CSA) Cement Provides Both Strength and Sustainability?by Peter Jason Content Enthusiast
Founder of US leading Cement Manufacturing Firm, Royal White Cement, Marcel Fadi, Explains What Makes Calcium Sulfoaluminate A Better Alternative than Portland Cements.
The prime significance of calcium sulfoaluminate (CSA) remains to be its rapid strength gain. However, there is much more to the perks of this fantastic eco-friendly cement. Below, the founder of the Royal White Cement, Marcel Fadi, shares what makes calcium sulfoaluminate (CSA) better than the conventional cement.
Established in 1999, Royal White Cement is a Houston-based company that manufactures and distributes Portland Cement products to construction markets across the planet. The company currently promotes a sustainable ecosystem by producing calcium sulfoaluminate (CSA) cement production material. With its this incredible endeavor to launch eco-friendly calcium sulfoaluminate (CSA) cement, The Royal White Cement has attained approval from the California Department of Transportation and U.S. Air Force to utilize CSA cement to construct and refurbish the North American concrete highway and runway roads. Royal White Cement is also part of the international corporate membership network of The World Cement Association (WCA).
Calcium Sulfoaluminate (CSA) Cement Has Better Alkalinity
The main mineral components in CSA cement are anhydrous calcium sulfoaluminate (4CaO·3Al2O3·CaSO4), dicalcium silicate (2CaO·SiO2), and gypsum (CaSO4·2H2O). The lime in CSA cement is bonded and not free, so its alkali is lower. The pH value is only 10.5-11; the pH of ordinary portland cement (OPC) is around 13, which is 100 to 300 times more alkaline than CSA cement. The low alkalinity naturally minimizes the chance for an alkali-aggregate reaction. This is important when the glass is used in the concrete, and the concrete is exposed to moisture.
CSA cement does not work like portland cement. Because of the much lower alkalinity, they don’t work with pozzolans, so using pozzolans like silica fume, metakaolin, and VCAS as a cement replacement to boost strength or reduce cement content (and thus restore or even improve the strength relative to 100% OPC) just won’t work. Compression tests performed by CCI showed a 30% loss of strength at both one day and seven days when 20% of the CSA cement was replaced with VCAS.
Calcium Sulfoaluminate (CSA) Cement Requires Less Curing Time
Curing with CSA is important, but wet curing durations are often measured in hours, not days or weeks. Optimal hydration and slab stability are achieved when the CSA concrete is kept moist for at least 3 to 4 hours after casting. During the initial hydration phase, the concrete demands moisture, and the rapid reaction generates significant heat. “If sufficient moisture is not provided during curing, cracking and curling are possible. When moisture is provided through ponding or repeated wetting during the first few critical hours, long-term stability and strength are preserved and ensured,” says Fadi.
An Eco-Friendly Alternative for Portland Cement
Fadi reveals that CSA cement can and must be used as an alternative for Portland cement, reducing carbon emission levels.
Since CSA’s do not react with pozzolans, none are needed to achieve high strengths and eco-friendly concrete. This simplifies mix design and minimizes inventory. All you need to do is replace 100% of the cementitious material in your current mix design, eliminating the pozzolans. Using pozzolans with CSA cement can actually weaken the concrete, so it is best to avoid it, and you will have better strength.
Superplasticizers, especially polycarboxylates, and viscosity modifiers work the same with CSA as with portland cement. Other exotic admixtures like liquid silicates or accelerating agents are not necessary and may not go with CSA cement. Conventional cement retarders are not compatible. Only special citric acid-based retarding admixtures made for CSA cement will work.
Calcium Sulfoaluminate (CSA) Cement Gives You Color Choices
The best thing is that CSA cement is available in a light buff or tan shade. This means you can give a twist to dull, white concrete structures using CSA cement. Be mindful of experimenting with hues while using the CSA cement, and you will love the final results.Additionally, CSA cement is compatible with concrete pigments, and they can be dyed, and acid stained, just like Portland cement. Decorative aggregates, metal, and glass are all compatible, so specialty embedment and exposed aggregate looks are all possible.
Created on Nov 10th 2020 11:29. Viewed 354 times.