Performance evaluation of limestone mortars for elevated temperature application in nuclear industry

In fast breeder nuclear reactors, sodium is used as a coolant. Accidental spillage of sodium, which is at an operating temperature of 500-550°C, can cause damage to the structural concrete in several ways. For this reason, a sacrificial layer of limestone aggregate concrete is provided over the conventional siliceous aggregate concrete. This paper presents the performance evaluation of mortars at 550°C, in the absence of sodium, in order to understand the behavior under only thermal exposure. The mortars were made with limestone as fine aggregate and with four types of cement. Apart from studies on mortar with limestone and conventional cements, performance evaluation of geopolymer paste and mortars at elevated temperatures was carried out to study the suitability of this new technology for sodium resistant applications. The different mixes were ranked based on the performance in the compressive strength and mass loss tests and relative performance indices were developed. © 2012 Taylor & Francis Group.