Cleaner Engineering and Technology (Feb 2022)
Engineering performance of metakaolin based concrete
Abstract
The sustainable development goal (SDG) 14 of the 2030 Agenda for Sustainable Development aims at protection, conservation, and management of coastal ecosystems and resources, including by strengthening their resilience, to avoid significant adverse impacts. Coastal/marine structures are exposed to aggressive environmental conditions, such as chloride laden environment. Deterioration of reinforced concrete structures located in a coastal/marine setting can influence the safety, economic and sustainability aspects of the society. Hence, there is an increased need for sustainable materials with the ability to reduce the effects of chloride attack in concrete. This experimental study aims to investigate the engineering properties of metakaolin (MK) based concrete exposed to chloride attack. The investigation was conducted for different w/b ratios of 0.54–0.61. The MK, utilised as cementitious material, was varied from 0 to 20% with an increment of 5% and ages of concrete from 7 to 56 days were considered. The effects of the above-mentioned parameters on the various properties of concrete such as workability, compressive and flexural strength, durability, resistance to chloride attack and microstructure properties of the concrete samples were investigated. From the favourable strength and durability results that were observed during the experimental study (optimum compressive strength of 49.8 MPa for 10% MK and optimum flexural strength of 8.35 MPa for 5% MK), it can be concluded that MK is a feasible supplementary cementitious material for combatting chloride attack in coastal/marine concrete structures. The obtained results, in combination with the lack of carbon dioxide CO2 released during the MK manufacturing process, further highlights the positive influence of MK on improving the serviceability and sustainability states of coastal/marine structures.
