They serve during the execution of the works, the casting of the fresh concrete and the obtained shape and dimensions of the concrete elements, as well as for their support during the time necessary to strengthen the concrete, until the necessary mechanical resistance is obtained. Although the formwork is not a component of a definitive construction, having only a temporary role, they are of great importance in realizing the concrete and monolithic reinforced concrete works. First of all, this importance results from the role of the formwork itself to give the desired shape to the fresh concrete and maintain it until it is strengthened, influencing the surface quality of the concrete elements that come into contact with the formworks. Secondly, the importance of the formworks consists of the technical and economic influence they have on the concrete and reinforced concrete constructions, in terms of cost, labor consumption, materials and duration of execution. The influence exerted by the surface of the formwork on the quality of the superficial layer of the concrete is that related to the appearance of the concrete after decoking. For the building elements to be laid, the surface of the concrete must not be flat and it is good to be even more rough to increase the adhesion of the plaster.
Sometimes, for this purpose, the shuttering is intentionally executed with a striated surface. For building elements that do not render and whose surface remains apparent, it is necessary that the surface of the formwork be as smooth as possible, in order to obtain a uniform surface of the apparent concrete. In the vicinity of the shuttering panels, the removal of air bubbles from the concrete mass is influenced by the nature of the shuttering surface. A smooth surface with a smooth, smooth, smooth surface, favors the elimination of these bubbles. In all cases it is also necessary that the surface of the formworks does not adhere to the fresh concrete, so that neither the formwork nor the concrete will deteriorate. If this adhesion is not hampered, the chippings can be broken off from the formwork or concrete. Reduction of adhesion between the formwork surface and concrete can be achieved by lubricating the formwork surfaces prior to use with suitable products or using glass fiber reinforced polyester moldings whose adhesion to concrete is reduced.