| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce a low contractive concrete which can effectively use relatively coarse coal ash that has a Blaine specific surface area of <3,300 cm2/g and has scarcely effectively been used, and can extremely reduce the contraction even when not mixed with an expanding agent or a contraction- reducing agent. SOLUTION: This low contractive concrete uses as a binder a coal ash- Portland cement mixture comprising coal ash having a Blaine specific surface of <3,300 cm2/g and Portland cement in a weight ratio of 3:7 to 7:3 in an amount of 300 to 400 kg/m3, and has a unit water content of 150 to 180 kg/m3, a fine aggregate rate of 45 to 50%, and a high performance water-reducing agent or high performance AE water-reducing agent/binder ratio of 0.5 to 1.5%. The coal ash is preferably coal ash not subjected to a classification treatment.</p> |
