Mechanical Properties and Water Diffusion in Polyester Polymer Concrete

Abstract

The behavior of polymer concrete (PC) and polyester polymer when exposed to water was investigated over a maximum period of 1 and 3 yr, respectively. Also the effect of sulfuric acid (H\d2SO\d4), sodium hydroxide (NaOH), and sodium chloride (NaCl) solutions on the strength of PC was studied. All the chemical solutions including water reduced the compressive strength of PC. The decrease in strength was dependent on the type, concentration, and pH of the corrosive solutions. The compressive strength of PC (cylinders 38 mm in diameter) in water decreased from 66 MPa (9,600 psi) to 45 MPa (6,500 psi) over a period of 12 months in a decreasing rate. A similar trend was observed for the splitting tensile strength. The reduced compressive and tensile strengths corresponded to the maximum water uptake in the PC (1.1 cm³ of water per 100 cm³ of PC). However, there was almost a complete recovery of the compressive strength upon heating the PC. A simple model based on the theory of diffusion was developed to predict the strength degradation rate for PC in water. The diffusion coefficient for PC in water was found to be 2.5x10\u-¹¹m²/s (2.3x10\u-¹\u0 sq ft/s). Treatment of PC with a silane coupling agent reduced the diffusion coefficient by more than one order of magnitude. The diffusion model is also used to verify other published data on polyester polymer concrete.