Considerations for the Construction, Implementation and Economic Evaluation of Geopolymer Permanent Formworks (GPFs): A New Approach to Protect Concrete Structures Against Aggressive Environmental Factors

One of the most significant damages of reinforced concrete is caused by chloride attacks. Solutions including the use of coatings or special concrete with low permeability have been proposed to promote concrete durability in previous research. Geopolymer mixes is a viable alternative in this context. Notwithstanding the advantages of geopolymer, problems with quick setting, shrinkage, increased cost, etc., may make its use problematic. Using permanent formworks (PFs) will therefore be a solution in this respect. PFs can be used both during the construction and during the repair of the structures. In this study, the considerations of fabricating PFs as well as their on-site implementation are examined. Compressive strength, impact resistance during transportation and installation, chloride ions penetration depth, and capillary absorption (from the seams and bulk) are among the experiments which are carried out to assess the performance of PFs. The significant increase in the service life of structures under chloride attack, the elimination of a part of the molding process in the construction of new structures, and the minimization of the low quality of execution are among the advantages of using PFs. The results reveal that the performance of PFs under harsh environmental conditions is appropriate. Although the use of polyurethane mastic in the seams has favorable results, reducing the number of seams decreases the probability of PFs damage. Although the implementing cost of PFs is slightly higher than conventional concrete (similar to 37%), the life cycle cost assessment of the structure shows economic savings if PFs are applied.