Effect of surface curing condition on the humidity field and moisture transfer in concrete

Abstract

In order to study the influence mechanism of different curing methods on the humidity field and scientifically design the surface curing methods, the humidity field of C30, C50 and C80 concrete cured with plastic film (PF), controlled permeability formwork liner (CPFL) and moisture retention curing film (MRCF) was measured by the designed testing device. And the pore structure of cement paste in the surface area of concrete with different curing methods was analyzed by mercury intrusion pore test (MIP). The theoretical calculation model for concrete humidity field considering the influence of surface curing method was also established. The results show that: CPFL curing improves the compactness of the concrete surface area by eliminating excess water and gas, reducing the rate of water loss and humidity decrease during the later drying process. It is more effective for the low strength concrete; MRCF curing extends the humidity saturation period and improving the final humidity level. It is more effective for the high strength concrete; PF curing creates an almost absolute humidity environment to prevent the moisture transfer during the curing period; The established model can accurately describe the impact of three different curing methods on the humidity changes for different strength concretes. It can be used to quantitatively analyze the humidity changes of concrete under different curing and environmental conditions. This study systematically clarifies the effect mechanism of different types of surface curing methods on the humidity field of concrete for the first time. And it will provide theoretical support for the scientific selection of concrete curing methods and accurate prediction of humidity field.