|
Title |
Relation between Autogenous Shrinkage of Concrete and Relative Humidity, Capillary Pressure, Surface Energy in Pore
|
|
Keywords |
자기수축 ; 상대습도 ; 표면에너지 ; 모세관압력 ; 공극 autogenous shrinkage ; relative humidity ; surface energy ; capillary pressure ; pore |
|
Abstract |
Humidity and strain were estimated for understanding the relation between humidity change by self-desiccation and shrinkage in high-performance concrete with low water binder ratio. Internal humidity change and shrinkage strain were about 10%, 4% and 320× 10-6, 120 H 10-6 respectively on concrete with water binder ratio 0.3, 0.4 and from the results, humidity change and shrinkage represented the strong linear relation regardless of mixture. For specifying the relation on internal humidity change and autogenous shrinkage strain, shrinkage model was established which is driven by capillary pressure in pore water and surface energy in hydrates on the assumption of a single network and extended meniscus in pore system of concrete. This model and experimental results had a similar tendency so it would be concluded that the infernal humidity change by self-desiccation in HPC originated in small pores less than 20 nm, therefore controlling plan on autogenous shrinkage might be focused on surface tension of water and degree of saturation in small pore.
|