The effect of using controlled permeability formwork on the durability of concrete containing OPC and PFA

This paper presents a study to assess the effect of using the controlled permeability formwork (CPF) on the durability of ordinary Portland cement (OPC) and pulverised fuel ash (PFA) based concretes cured for different times. An experimental program has been undertaken in which trial specimens have been tested at various ages following different curing periods and regimes. Various tests were conducted and assessed using a range of destructive and non-destructive techniques such as Schmidt hammer, water permeability, sorptivity absorption, ultrasonic pulse velocity, and chloride diffusion and resistivity. The durability and strength test results during the period from 28 to 90 days are presented to compare the effects of using CPF with those of traditional (plywood) formwork on OPC and PFA 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. However, the effects are minimal on the bulk properties of the concrete.