Hiroaki Sano

Availability of Density Measuring Methods Estimating Gypsum Hemihydrate Content in Reclaimed Gypsums

In order to utilize reclaimed gypsums (gypsum board waste) derived from waste plasterboards as geo-materials, thermal behaviors of the reclaimed gypsums and reagent gypsum are investigated in this paper. As the results, it was found that the dihydrate gypsum is changed into the hemihydrate gypsum under thermal condition of 90°C and the hemihydrate gypsum is changed into anhydrite under that of 120°C with heating of 24 hours. The followings were clarified in this paper. The cement density measuring method was available in order to measure the density of reclaimed gypsums; that density was depended on the drying conditions of the reclaimed gypsums; and the density measuring method was appropriate to estimate the gypsum hemihydrate content on reclaimed gypsums.

A STUDY ON UTILITY OF MIXED MATERIALS USING FLY ASH AND FLUE GAS DESULFURIZATION WASTES AS SUBBASE COURSE MATERIAL

本研究では石炭火力発電所産副産物であるフライアッシュおよび排煙脱硫スラッジの道路下層路盤材としての有用性を検討するたあに, まず, 室内でこれらを混合してから締固あるまでの時間間隔と作製した供試体ゐ養生温度とを種々変えたときの一軸圧縮強さや体積変化率を調べた. 次に, 2箇所の現道で試験舗装を実施して交通開放後の路面性状や路盤支持力などを測定した. 試験結果より, 当該材料は下層路盤材としての品質規格を満足し, 舗装の供用性, 耐久性はともに良好であることが示された.