Self-heating mortars with using graphene oxide and increasing CSH gel formation with the direct current application

Abstract

Graphene oxide (GO) is that the product of the exfoliation of graphite by chemical processes. GO has a potential candidate to be used as a nano reinforcement material in cement-based systems due to its water dispensability, quite good mechanical properties, and high aspect ratios. In this research, the effects of different water/binder (water/cement) ratio (0.55, 0.70, 0.90, and 1.00) and graphene oxide on mortars to which applied DC stress intensity have been investigated. In experiments, 4cm x 4cm x 16cm wood molds (electrical isolated) have been used. Immediately after mixing into the mixtures, a stress intensity of 25 V was applied for 24 hours with a DC power source. Experiments were conducted in the laboratory conditions. Effect on hydration internal temperatures of the mortars with direct current application has been investigated. It is also researched that, the effect of graphene oxide on hydration temperature by direct current (DC) application on mortars. Through the application of 25 V DC to the 300 dosage mortars to which have different w/c ratios (0.55, 0.70, 0.90 and 1.00), their internal temperatures are increased as 1.26 °C, 1.78 °C, 4.25, and 3.30 °C, respectively. When they are compared to the same water/cement ratio of reference samples, it has been observed that, when 0.025 % ratio of graphene oxide has been added to admixture and also direct current has applied, hydration temperature values of mortars have been increased. Microscope views have been investigated from 300 dosage mortars whose w/c ratio is 0.90 and it is determined that CSH gel formation increases as using 0.025 % GO and DC stress intensity application. It is concluded that hydration reactions can be accelerated by applying electric current to the mortar and adding graphene oxide to the mixture.