Title: Carbonation Resistance of Polymer Cement Mortars (PCC)

Author(s): B. A. Oye and H. Justnes

Publication: Symposium Paper

Volume: 126

Issue:

Appears on pages(s): 1031-1046

Keywords: carbonation; concretes; durability; epoxy resins; latex; mortars; polymer-cement concretes (PCC); Materials Research

DOI: 10.14359/2485

Date: 8/1/1991

Abstract:
Ten different polymers, six latices, and four epoxy systems were added to two base mortars of water-cement ratio (w/c) = 0.55 and 0.40. The latices were PMMA, PMMA/PBA (two compositions), PVAc/PE/PVC, PVAc/Veo Va and SBR. Two of the epoxies were based on Bisphenol A resin (epoxy F1 and L), while the other two also contained a reactive thinner based on hexyleneglycol diglycidylether (epoxy F0 and V). The hardeners were both polyamine (epoxy L) and a water-soluble hardener based on polyamide. The cement paste in the base mortars was partly substituted with 5, 10, 15, and 20 volume percent polymer (10 and 20 volume percent for the epoxies). The binder volume was kept constant in all mortars, and the w/c was constant within each series. The carbonation rate of the PCCs with w/c = 0.40 is equal to or higher than the unmodified mortar. The only exceptions are the 15 and 20 percent PVAc/PE/Pvc-modified mortars, which withstand carbonation significantly better than the control. The epoxies L and V, together with the SBR PCCs, performed particularly poorly. Among the PCC with w/c = 0.55, PVAc/PE/PVC/PCCs, together with the 10 percent PMMA/PBA I PCC, performed better than the control. All the other PCCs resisted carbonation equal to or less than the control. In the latter case, however, it is difficult to state the contribution from the air content which may imply that the performance of the polymer actually is even better. The results are assessed with respect to the degree of hydration of the PCCs, their air content, the replacement of cement binder with polymer, and the neutralization effect following a possible hydrolysis of the polymer.