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Study on Improvement of Early Strength of Highly Durable Concrete by Combined Use of Chemical Admixtures

Sora Suto and Kazuhito Niwase
National Institute of Technology Hachinohe College, Aomori Hachinohe, Japan

Abstract—At present, in Japan, the deterioration of social capital has become a serious problem, and from now on, together with the decline of the population that supports it, there is a concern about the maintenance of social capital. Japan's social capital stock was concentrated in the period of high economic growth. They are required to be maintained and managed strategically in the future. On the other hand, it is important for new products to have long-term durability. Concrete that combines low heat Portland cement and fly ash (LPC-FA concrete) is considered to be one of the materials with excellent durability based on previous research. However, when generally used, there is a problem that the early strength is low. Therefore, in this study, basic research was conducted with the aim of improving the early strength by using a combination of chemical admixtures. The chemical admixtures used in this study are Master Ease (hereinafter ME) as an air entraining and high-range water reducing admixture and Master X Seed (hereinafter MXS) as an accelerating admixture. The 3 days strength of LPC-ME-MXS concrete was as strong as OPC-ME. And, it was confirmed that LPC-ME-MXS expresses the same strength as OPC-ME-MXS at the 28 days strength. From these results, it has become clear that the combination of ME and MXS can improve the early strength. In the future, we will continue to conduct tests until long-term material age, compare data, and examine the chemical basis for the cause of strength development improvement.

 
Index Terms—high durability concrete, LPC-FA, Air entraining and high-range water reducing admixture, accelerating admixture

Cite: Sora Suto and Kazuhito Niwase, "Study on Improvement of Early Strength of Highly Durable Concrete by Combined Use of Chemical Admixtures," International Journal of Structural and Civil Engineering Research, Vol. 9, No. 2, pp. 175-179, May 2020. doi: 10.18178/ijscer.9.2.175-179