Early quality control of stabilised dredged material by correlating heat production with strength

This study explores the use of isothermal calorimetry to assess heat release during the initial phases of dredged sediment (DS) stabilisation with the primary goal of predicting the 28-day unconfined compressive strength (UCS) and enhancing the stabilisation process’ quality control. The study was performed on DS samples collected from Göta river, Gothenburg, Sweden. The water content of the raw DS was set to 138%, 185%, and 291%, and mixing was performed with water-to-binder ratios 4, 5, 6, 7, and 8 using a binder consisting of 40% Portland limestone cement and 60% slag. The heat release measurements were conducted during the first 7 days of hydration, non-destructive free–free resonance tests were performed at 7, 14, and 28 days of hydration, and the 28-day UCS was done to assess the compressive strength of stabilised DS. For each water content, a statistical analysis was performed to determine the strength of the relationship, specifically using linear regression, to assess how well early calorimetric data could predict the UCS, and a correlation was found between the 28-day compressive strength and heat release of stabilised DS after 48 h of hydration. By measuring water content and heat release in the early stages of stabilisation, it is thus possible to assess the binder content and predict the ultimate compressive strength of a treated DS.