Volume 2, Issue 2 (February 2005)
Effects of Vacuum Processing on Strength and Surface Hardness Properties of Concrete
In this experimental study, the effects of vacuum process on mechanical and physical properties of concrete were investigated by comparing mechanical properties of vacuum processed and half vacuum processed concrete specimens with those of control specimens. Vacuum equipment was used to apply vacuum to fresh concrete in order to extract water from floor concrete. Compressive strength and some other test results obtained from both vacuum processed and plain concrete core specimens were evaluated and then compared. Test results have shown that the compressive strength of vacuum processed concrete specimens increased substantially due to the decrease in water/cement ratio by dewatering process. The effects of the process on compressive strength at early ages and on surface placement are much more pronounced. Some of the other properties such as dry density, unit weight, surface hardness, and surface porosity are also improved by vacuum dewatering process.