Thermal reactivity of slag cement binders and the response of high strength concretes to in-situ curing conditions

Abstract

Concretes placed in thick structural elements experimence high hydration temperatures and restricted access to moist curing. This is particularly the case in concretes with relatively high binder contents and low water/binder ratios. Under high temperature curing, thermally reactive binders show significantly enhanced development of early age properties which may be there is currently very little data on either the early age or medium-term properties of concrete subjected to the combined impact of high temperature and restricted moist curing. This is particularly the case for blended cements containing supplementary cementitious materials, in spite of such binders being increasingly specified in all forms of construction. In this paper, the early and medium-term performance of high strength concretes containing blast furnace slag subjected to in-situ curing is described. The thermal reactivity of slag blended cements is evaluated in relation to key early age engineering properties, which in turn were found to develop at substantially different rates. The prediction of early age properties using equivalent age principles is assessed.