This book provides a State of the Art Report (STAR) produced by RILEM Technical Committee 254-CMS ‘Thermal Cracking of Mas-sive Concrete Structures’. Several recent developments related to the old problem of understanding/predicting stresses originated from the evolution of the hydration of concrete are at the origin of the creation this technical committee. Having identified a lack in the organization of up-to-date scientific and technological knowledge about cracking induced by hydration heat effects, this STAR aims to provide both practitioners and scientists with a deep integrated overview of consolidated knowledge, together with recent developments on this subject.

Methods of controlling mass concrete temperatures range from relatively simple to complex and from inexpensive too costly. Depending on a particular situation, it may be advantageous to use one or more methods over others. Based on the author’s 50 years of personal experience in designing mass concrete structures, Thermal Stresses and Temperature Control of Mass Concrete provides a clear and rigorous guide to selecting the right techniques to meet project-specific and financial needs. New techniques such as long time superficial thermal insulation, comprehensive temperature control, and MgO self-expansive concrete are introduced. Methods for calculating the temperature field and thermal stresses in dams, docks, tunnels, and concrete blocks and beams on elastic foundations Thermal stress computations that take into account the influences of all factors and simulate the process of construction Analytical methods for determining thermal and mechanical properties of concrete Formulas for determining water temperature in reservoirs and temperature loading of arched dams New numerical monitoring methods for mass and semi-mature aged concrete

Recently, activities and interest in monitoring the heat evolution of cement hydration in concrete have increased. This is because the development of early-age concrete properties (such as workability, setting time, strength gain, and thermal cracking resistance) is predominantly influenced by the kinetics of cement hydration. Various test methods are currently available for measuring heat of cement hydration; however, most existing methods require expensive equipment, complex testing procedures, and/or extensive time, thus making them unsuitable for field application. Although ASTM C 186 is used for determining the heat of hydration of cement, there is no standard test method for concrete. The overall object of this three-phase study is to identify, develop, and evaluate a standard test procedure for monitoring pavement concrete using a calorimetry technique. It is envisioned that the newly developed calorimetry test method will be able to verify appropriate concrete proportions, to identify potentially incompatible materials and conditions, and to predict concrete performance. The primary objective of Phase II (presented in this report) is to establish a standard test procedure as well as the methods for interpreting the calorimeter test results. The newly developed calorimeter test is completed more quickly than ASTM C 186, in approximately 24 hours. Among a number of uses, the test can be utilized as a quality control measure for prescreening concrete materials and a prediction tool for early-age cracking. The Phase II results demonstrate that the new calorimetry test method has a high potential for detecting concrete incompatibility problems, predicting fresh concrete properties (such as set time), and assessing hardened concrete performance characteristics (such as strength gain and thermal cracking).