DYNAMIC MECHANICAL THERMAL ANALYSES OF POLYMERIC CONCRETE REPAIR MATERIALS

摘要

Composite materials comprising geologic fillers in organic polymeric matrices are commonly marketed for making expedient, durable repairs to existing concrete structures. Six commercially available polymer concretes designated for repairing damage in portland-cement concrete were selected for laboratory testing; two were methacrylates, two were epoxies, one was a urethane, and one was an elastomeric urea. Specimens were prepared and cured according to manufacturer recommendations. ASTM strength and modulus tests were performed to verify reported properties. Dynamic mechanical thermal analysis (DMTA) was performed in flexure over the temperature range -55 deg C to 200 deg C, at a scanning rate of 3 deg C/min. Plots of Ε', E'', and tan delta were obtained as functions of temperature. Onset temperatures of thermal transitions were identified, as well as the glass transition temperatures (T_g) of the materials. The epoxy based matrices demonstrated the lowest thermal tolerances of the material classes studied. Some of the polymer-aggregate composites exhibited significant strength reduction at temperatures which may exist in infrastructure applications; therefore, thermal tolerance should be considered when selecting concrete repair materials of this type.