Use of adiabatic calorimetry for performance assessment of concretes

Modern concrete construction involves the use of a variety of special concretes. While the design of such concretes accounts for the achievement of characteristics such as high strength, toughness, flowability, shrinkage compensation and so on, one aspect that is not sufficiently addressed is the heat evolution in such concretes. This can be of particular importance when the concrete mix uses a large amount of cementitious materials. Furthermore, heat development can also be a major problem for regular mixes when the concrete is not properly optimised for the composition and content of the binder. This paper reports on an extensive experimental investigation, using an adiabatic calorimeter that was developed in-house, on heat development in two categories of concretes – special high-strength concretes with compressive strengths of 60–100 MPa and ordinary regularly used concretes with strengths of 30–50 MPa. The relevant hardened properties of the concretes were also evaluated and compared. The results indicate that heat development is a serious issue in high-strength concretes, while suitable selection of materials for ordinary concretes can lead to a major reduction in the level of heat evolution in the early stages.