In April 2016, JIS A 5011-2 “Slag Aggregate for Concrete-Part 2 : Ferronickel Slag Aggregate” and JIS A 5011-3 “Slag Aggregate for Concrete-Part 3 : Copper Slag aggregate” were revised. These revisions introduce pro visions concerning the environmental safety quality of slag aggregate, and establish a new standard for ferronickel slag coarse aggregate. This paper gives an outline of the “Recommendations for Design and Construction of Concrete Structures Using Ferronickel Slag Aggregate” and “Recommendations for Design and Construction of Concrete Structures Using Copper Slag Fine Aggregate” of the Japan Society of Civil Engineers, which have been revised in response to these JIS revisions, and further made to incorporate the latest research findings.
The current Technical Committee on the Deterioration of Concrete under Natural Weathering Conditions (Chairman: Professor Noboru Yuasa, Nihon University) was established as the successor of the Technical Committee on Performance of Concrete under Natural Weathering Conditions (Chairman: Professor Eiji Kamada, Hokkaido University) established in 1991, and the Technical Committee on the Evaluation of the Performance of Concrete under Natural Weathering Conditions (Chairman: Professor Noboru Saeki, Hokkaido University) established in 2003. This paper provides an introduction to the deterioration of concrete under natural weathering conditions, and explains the Manual of LongTerm Exposure Testing of Concrete produced by the Technical Committee on the Deterioration of Concrete under Natural Weathering Conditions to deal with the exposure testing issues identified by the two former aforementioned committees. It goes on to give an overview of the exposure site and exposure tests conducted by Nihon University, and regarding actual operations, introduces the wireless and LAN-based system for the acquisition of environmental information and test data.
In buildings with 25 floors or less aboveground that are supported by concrete filled steel tube (CFT) columns, axial loads are generally transferred through 2- or 3-story columns to underground steel-encased concrete columns. Such construction often is one of the factors that increase construction cost and period. To remedy this, the author proposes a hybrid column system implemented in a single underground story to transfer axial loads to CFT columns consisting of steel of large size and concrete. This paper gives an outline of the experiments carried out on this structure and the results obtained.