At first we will learn why membrane curing for concrete is required. This is due to deficiency of water i.e. the region where water shortage is acute, membrane curing is adopted. In case of concreting in inaccessible and difficult to reach regions, supervision after concreting with qualified supervisor or engineers is not possible.
In this region the workmanship of local worker is also low and sometimes they have no idea about importance of curing-leaving no way to depend on them and membrane curing is adopted. The further discussion on different aspects of membrane curing will be published in upcoming posts-keep tuned.
Bituminous compounds are used to form a impervious film over concrete surface to prevent loss of moisture due to evaporation. But there have a limitation of using bituminous compounds as moisture barrier. This is it absorbs heat from environment being black in color. This causes increase in temperature of the concrete. We all know hydration of concrete depends not only on moisture loss but also depends on ambient temperature. This limitation is overcome by applying a bright color coating on bituminous compounds. For economy this white coating is done by lime wash.
Bituminous compounds sometimes are used in the interface of concrete and ground to detach both from come in contact as adsorption of water from concrete to ground can also hinder hydration process.