The mechanical, transport and thermal properties of mortar and concrete containing waste cork

This study examines the impact of cork used as sand replacement or stone replacement on the plastic, mechanical, transport, microstructural and thermal properties of mortar and concrete. Mix design variables include the percentage of cork, cork size, and the cork blend. Key findings from this study revealed that: (i) The greatest early age (days 3 and 7) cube strengths were achieved by 24 h moisture saturation of the cork followed by draining it prior to use in concrete. Heat exposure of 50 °C or 100 °C resulted in detrimental effects on cube strength gain. (ii) Finer cork sizes were most beneficial to achieve optimum mechanical, and transport properties however high permeability values indicate that concrete-cork composites considered in this study may be vulnerable to poor durability performance. (iii) Greater percentages of cork as sand or stone replacement had the greatest impact on thermal resistance. (iv) Blending multiple cork sizes to achieve a greater size distribution of cork granules used as sand or stone replacement did not yield notable beneficial results.