2009 Fiscal Year Final Research Report

Study on the Reducing Effect of Water Content and Cracking of Concrete Containing Carbon-free Fly Ash

Research Project

Project/Area Number	20760377
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Building structures/materials
Research Institution	Oita University
Principal Investigator	OTANI Toshihiro Oita University, 工学部・福祉環境工学科建築コース, 准教授 (00315318)
Project Period (FY)	2008 – 2009
Keywords	フライアッシュ / 未燃カーボン / 粒子形状 / コンクリート / モルタル / 流動性 / 乾燥収縮ひずみ / ひび割れ
Research Abstract	Characteristics of two types of Carbon-free Fly Ash which complies with "Fly ash class II" of JIS A 6201, were measured. And these shapes of the particles were analyzed with SEM image to clear the influence of Carbon-free Fly Ash to slump of concrete. The results showed that the shape and size distribution are different even if same class of Carbon-free Fly Ash. And the fly ash that the improvement effect is low has a lot of non-spherical particles. Then, drying shrinkage cracking tests was carried out. The test result showed that the cracking age of concrete containing fly ash which content is 20% is delayed than that of plain concrete.

(4 results)