The site exposure of concrete cast using controlled permeability formwork

摘要

This paper presents a study to assess the effects of site exposure on the durability of concrete cast with ordinary Portland cement (OPC), pulverised fly ash (PFA) and ground granulated blast furnace slag (GGBS) using the controlled permeability formwork (CPF). An experimental program has been undertaken in which trial specimens have been placed on exposure sites at coastal locations in Australia. Various non-destructive tests were conducted such as Schmidt hammer, water permeability, air permeability, ultrasonic pulse velocity, steel potential mapping, linear polarisation resistance corrosion rate monitoring, chloride diffusion, accelerated chloride diffusion, and resistivity. The durability data are presented to compare the effects of using CPF with those of traditional (plywood) formwork for OPC, PFA and GGBS concrete mixes, as specified on actual construction projects in Australia. The results indicate that CPF gave improved performance compared to the traditional formwork for surface properties of concrete.