A comparative study of petroleum coke and silica aerogel inclusion on mechanical, pore structure, thermal conductivity and microstructure properties of hybrid mortars

Development of cost-effective and energy - efficient materials is an on-going effort in construction sector. For this purpose, researchers have focused on utilizing various industrial by - products and nano thermal insulation materials in cement - based mixtures in recent years. This paper presents a comparative study on mechanical, pore structure, thermal conductivity properties and microstructure morphology of hybrid mortar mixtures containing petroleum coke as a partial replacement of sand (0%, 10% and 15%, by weight) and silica aerogel powder as a cement additive (0.35%, 0.7% and 1.0%, by weight). Results showed that a thermal conductivity reduction of 21.83% was determined at an aerogel content of 0.35% with higher compressive, flexural strengths and toughness capacities. Moreover, there was an insulation enhancement in the petroleum coke-incorporated samples up to 33% at a replacement level of 15%. However, in the case of equivalent thermal conductivity, compressive toughness and post - peak toughness capacities of aerogel-incorporated mixtures were higher up to respectively 20% and 17% in comparison to petroleum coke-incorporated mixtures. This research opens up a new perspective in the design of hybrid cement mortars containing silica aerogel powder and petroleum coke with the optimization of mechanical-thermal insulation properties.