Curing time and heating conditions for piezoelectric properties of cement-based composites containing PZT

Samples of piezoelectric cement, consisting of equal volumes of lead zirconate titanate and type I Portland cement, were treated through a heating technique and cured for controlled lengths of time to produce notable piezoelectric properties. Piezoelectric properties were measured by considering curing times of 1, 3, and 7 days, and applying 23 degrees C or 140 degrees C treatments on the piezoelectric cement samples. Curing time showed minor effects on the piezoelectric strain factor d(33), relative dielectric constant epsilon(r), and electromechanical coupling coefficient K-t at late ages for specimens that were cured for more than 3 days. Pretreatment with higher temperatures on piezoelectric cement is expected to obtain higher d(33) and epsilon(r) values than posttreatment would obtain. Two heat treatments at 140 degrees C and 1 day of curing for piezoelectric cement provide superior d33 and epsilon(r) values, with d(33) = 110.9 pC/N and epsilon(r) = 756 at 100 days. However, it is necessary to enhance the K-t of piezoelectric cement at least 3 days' curing. 2016 Elsevier Ltd. All rights reserved.