Characterization of the mechanical properties of polyacrylic acid-metal oxide concretes

Abstract

Several samples consisting of polyacrylic acid (PAA) and metal oxides (MO, with M = Ca, Mg and Zn) and Al(OH) 3 were reacted at room temperature along with inert Al 2O 3 to produce concrete-like composites. Characterization of the mechanical properties (tensile strength) was carried out, as well as characterization of the volume changes in various stages of curing. The results show that these materials exhibit similar elastic behavior before failure, but the curing time influences the strength values greatly for each system, in spite of the fact that all exhibit similar Young's modulae. Also, further hydration of the samples, after being initially cured in air, results in a decrease of the mechanical performance, the amount depending on the specific PAA-MO system. Subsequent recovery to even higher strength figures was obtained by simple water evaporation.