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Early age behaviour and cracking risk of concretes containing GGBS Fragkoulis Kanavaris (24170043) PUREID: 649015338 Nowadays, due to the increased need for sustainable construction material s, many concretes produced contain cement replacement materials, such as ground granulated blast furnace slag (GGBS). However, limited information exists regarding the effects of temperature, time and GGBS replacement level in the early age behaviour of concrete. Due to its decreased rate of strength gain at early ages, GGBS has not yet gained popularity in applications where high early age compressive strength is required. On the other hand, GGBS has been used to reduce early temperature rises in concrete which are thought to be responsible for thermal cracking occurrence. However, its decreased strength gain rate and potentially higher shrinkage may result in neglecting the benefit from the reduced peak temperatures which creates a controversy regarding its effectiveness in mitigating thermal and shrinkage cracking.<br><br>The purpose of this thesis is to contribute to the up-to-date knowledge regarding the early age behaviour and cracking risk of GGBS concrete. To satisfy this objective, the combined effects of temperature, time and GGBS content on the heat of hydration, mechanical and thermal properties as well as on the cracking risk of concrete were experimentally investigated. It appeared that although the autogenous shrinkage of GGBS mixes is increased at high curing temperatures, the tensile strength enhancement emerging from such temperatures results in GGBS mixes being capable of withstanding restraint stresses more effectively than PC concrete. Additionally, the maturity method was reviewed and improved accordingly in order to be also applicable for GGBS concretes, also for properties other than compressive strength and by its combination with numerical simulation of the thermal-shrinkage stresses, a design approach for early age cracking mitigation was proposed.<br><br>This research study provides a comprehensive investigation on the effects of temperature on the early age behaviour and cracking risk of concretes containing GGBS using experimental and numerical techniques. It could be used as a guide in order to determine appropriate curing regimes and mix proportions of GGBS concretes in applications where early age compressive strength and/or cracking risk minimisation is required.<br> 2026-10-01T16:22:37Z Text Thesis 10.17034/32641527.v1 https://figshare.com/articles/thesis/Early_age_behaviour_and_cracking_risk_of_concretes_containing_GGBS/32641527 All Rights Reserved