Evaluation of the comparative effect of macro polypropylene fiber sand reinforcing bars in controlling and reducing the severity of plastic shrinkage cracking in concrete airfields in harsh environmental conditions

Controlling and reducing plastic shrinkage cracking in airfield concrete pavements, as one of thesensitive structures in civil engineering, is of great importance in harsh environmental conditions. Despitethe proper performance of reinforcing bars in most concrete structures, it is important to use new materialsin order to further reduce the severity of cracking and eliminate the disadvantages of using bars. The presentresearch examined the comparative effect of macro polypropylene fibers and reinforcing bars in controllingand reducing the severity of plastic shrinkage cracking in concrete airfields in harsh environmentalconditions. Reference concrete slabs, steel mesh and macro polypropylene fibers were made and then themean width, length and area of plastic shrinkage cracking were evaluated using ASTM C۱۵۷۹ standardmethod and digital image analysis. The results showed that both reinforcing elements caused a significantchange in cracking behaviour. Steel mesh was able to significantly reduce the length and area of crackingup to ۳۲% and ۴۰%, respectively, and macro polyproline fibers were able to reduce the length and area ofcracking up to ۶۷%, and ۶۸%, respectively. Both reinforcing elements did not have a significant effect inreducing the crack width. It was seen that macro polypropylene fibers had a better and higher performancecompared to steel mesh in controlling the length and area of cracking due to their presence in different partsof the structure, especially on the surface of the concrete slab and being placed at different angles, as wellas higher resistance properties. In the end, it was stated that by using auxiliary measures, it is possible toreduce the width of cracking in airfield concrete pavements containing polypropylene macro fibers use theadvantages of macro polypropylene fibers in these structures.

کلیدواژه ها:

Concrete Airfield ، Concrete pavement ، plastic shrinkage cracking ، macropolypropylene fibers ، reinforcing bars ، steel mesh ، cracking severity ، harsh environmental conditions.