When fresh concrete is laid at the site then proper curing of concrete is required, because structures are exposed to the environment and in these conditions if there is no such an arrangement against the environment, then there are many factors that affect the workability of concrete and temperature is One of them. Temperature, almost in every aspect has negative effects on the properties of concrete and same is the case with the workability of fresh concrete.
When temperature increases, then in the same proportion workability of fresh concrete decreases. The reason that stands behind is “ when temperature increases then evaporation rate also increases due to that hydration rate decreases and hence, concrete will gain strength earlier “. Due to fast hydration of concrete, a hardening comes in concrete and that decreases the workability of fresh concrete. Therefore, In return manipulation of concrete become very difficult.
Effect On Flowability Of Concrete
When temperature increases then fluid viscosity increases too and that phenomenon affects the flow ability of fresh concrete. Flow ability of concrete starts reducing and hence, as a result concrete workability decrease. And when workability of concrete decreases, then due to the less flow ability of a fluid, voids within the mass of concrete develops more.
This is because deeper air voids in concrete only fill, if freshly mixed fluid has the ability to move deeper inside the small opening in the concrete. As in the present case due to higher temperature, viscosity of fluid increases and that viscous of fluid resists the movement of fluid.
Now In case when empty voids left in the concrete, then number of weak points rise in concrete and that became the reason of a reduction in the strength of concrete.
It indicates that the temperature has a negative effect on the workability of concrete as well as strength up to some extent. Temperature decreases the setting time by increasing hydration rate and that increase the early age strength of the concrete.
This is an advantage that less time will be required before removing of form works on site, but this decrease the use of proper placement of concrete in the initial stages. And if concrete is not properly laid, then strength distribution will not remain the same throughout the cross-section.