Influence of PVA and PP fibers addition on the durability and mechanical properties of engineered cementitious composites blended with silica fume and zeolite

Over the past two decades the effects of different admixtures have been investigated on mechanical properties and durability of engineered cementitious composites (ECC). Despite this, materials such as silica fume and zeolite have not been thoroughly investigated. The present study was designed and implemented to evaluate the effects of silica fume, zeolite, and blast furnace slag (BFS) on engineered cementitious composites and to compare the mechanical properties and durability of the polyvinyl alcohol-ECC (PVA-ECC) and polypropylene-ECC (PP-ECC) specimens. For this purpose, specimens were subjected to adverse conditions in a 5% magnesium sulfate solution and lab conditions as the reference treatment to measure the post-treatment variations in their compressive strength, flexural strength, and mid-span deflection (MSD). Results demonstrated that PP-ECC was not only easier to manufacture but outperformed PVA-ECC in some respects as well. It was also observed that MSD increased in the PVA-ECC specimens but declined in the PP-ECC ones under identical increments in their BFS contents. Finally, all the specimens maintained under the lab conditions displayed the best performance in terms of strength and durability when 3% silica fume was added to their mixtures while the same addition led to the worst performance in the sulfate medium.