How Sika's Concrete Admixtures Help Make Japan’s Tallest Tower Quake-proof

Tall buildings need to avoid swaying in the wind and given the high likelihood of earthquakes in Tokyo, the most stringent standards apply. Hence, the foundation of the Azabudai Hills Mori JP Tower consists of a five-meter thick slab of ultra-high performance concrete. The tower was further strengthened by steel tubes filled with the same concrete mix. The superior strength was achieved by using Sika’s and the Japanese company MBCC’s concrete admixtures. MBCC is a global supplier of construction chemicals. Sika closed its acquisition in May 2023.

“With Sika admixtures, concrete is stronger, allowing stiffer concrete-filled tubes that meet the strictest specifications for earthquake resilience,” says Kazumasa Okabe, General Manager of Mori Building’s Structural Design Unit. Besides the high-performance concrete, Sika also supplied sealants from the Hamatite product range. The developer Mori Building also used liquid applied membrane from the Dyflex water-proofing portfolio on terraces and balconies.

“To deal with the complexity, most people just use products and suppliers they know,” explains Mori Building manager Okabe. “But in 2002, I was working on a skyscraper in Shanghai. With no standard Japanese solution available, I had to do my own research and I discovered the benefits of Sika’s pioneering polycarboxylate-based concrete admixtures. The strength and reliability won me over. Since then, I always ask for Sika solutions when designing new projects.” Not only Mori Building, other large construction companies in Japan are also using Sika materials for erecting skyscrapers.

Tetsuya Matsumoto, Head of Key Account Management at Sika Japan, explains that Sika’s superplasticizers enhance the workability of concrete, allowing it to be pumped to higher altitudes during construction. They also reduce the amount of water required, improving the strength-to-weight ratio. “With Sika admixtures, concrete is stronger, allowing stiffer concrete-filled tubes that meet the strictest specifications for earthquake resilience. Additionally, high strength concrete allows designers to create slimmer supporting columns providing more rentable space – with obvious commercial benefits.”

In terms of sales, Asia is currently less relevant for Sika than the USA or Europe. However, its sales in Asia with India, Japan, and China as key markets are growing rapidly. Last year, Sika achieved Asian-Pacific sales of 2.6 billion francs, almost a quarter of global sales. The region is likely to become the most important pillar in the medium term, as the world’s big megacities are all located in Asia, Sika CEO Thomas Hasler explained at the recent Global Analyst and Investor Day in Tokyo. It was the first time that Sika held such an event in Japan which emphasized the increased relevance of this market.

Source: Sika