2019 Volume 57 Issue 7 Pages 498-503
In response to deterioration and damage in structures using aggregate evaluated to be “harmless” under Japanese Industrial Standards (JIS) as a measure against the alkali-aggregate reaction of concrete, East Japan Railway Company has taken the lead since November 2011 in developing a new approach for the use of aggregate in blended cements and the like based on a finer reactivity classification of aggregates. The introduction of this approach for actual construction faced various challenges related to the supply of materials, the production of ready-mixed concrete, construction, and so on. As a pilot project, a continuous multi-level crossing construction project using concrete mixed with fly ash near Niigata Station was selected for the introduction of this new approach. Various aspects, including the effect of various fly ash mixing ratios in terms of ASR suppression, the construction of a ready-mixed concrete supply system, and measures for quality assurance during construction were investigated, and the applicability of the proposed approach was verified through actual application to said construction project.
