Microwave curing effects on the 28-day strength of cementitious materials

Microwave energy can be applied on the curing of the cementitious materials because of their water content. Isothermal heating, achieved best by feedb ack temperature control, is required to investigate properly the temperatur e effects on the properties. Type I Portland cement mortars, some with addi tions of appropriate amounts of pozzolanic material, such as slag, silica f ume: or class F fly ash, were cured isothermally with feedback temperature control at several temperatures. The curing times were determined by the in strumented penetration test, and 28-day compressive strengths were measured . Optimum curing conditions were found for 40 degrees C and 60 degrees C, b ut 80 degrees C was unsuitable for microwave curing. (C) 1999 Elsevier Scie nce Ltd. All rights reserved.