2018 Volume 72 Issue 1 Pages 83-90
In order to reduce the total carbon footprint and the energy consumption in sustainable construction, cementitious materials are produced with increasing amounts of alternative secondary raw materials such as fly ash and blast furnace slag. Several studies have been reported for the trial to increase the amount of minor additional constituents from 5％ to 10％ in Ordinary Portland Cement. But, significant degradation of physical properties at early age such as compressive strength and heat liberation was observed. To solve the problems, the energy-saving cement which contains both clinker with high C3A and 10％ of mineral additives was proposed.
In the present study, the expansion of mortars which is composed of alkali-silica reactive aggregate and cement added with 10％ of minor additional constituents, fly ash, lime stone powder and blast furnace slag, was measured by the accelerated mortar bar test for alkali silica reaction, ASTM C1260. The results showed that the expansion of mortars 14days after curing in NaOH 1mol/l at 80℃ decreased when cement with higher amount of C3A, 16％ was used, compared to that with lower amount of C3A, 10％. XRD/Rietveld analysis and 27Al MAS NMR revealed that the consumption of Ca（OH）2, CaCO3 and C3A and the increase in amorphous phase were enhanced when cement with high C3A was used.
