Experimental compression and tension strength of metakaolin mortars reinforced with polypropylene fiber

Reinforced concrete is the most commonly used construction material worldwide. The need for high strength concrete and increased service life of reinforced concrete structures led to the development of high performance concrete in the last decades. High performance concrete is typically a concrete prepared with pozzolanic admixtures, such as metakaolin. Use of pozzolanes in concrete microstructure have a long and successful history. In fact, their usage return to before invention of present Portland cements about 2000 years ago. Utilizing pozzolanes as a part of the cement with due attention to cement deficit and it's producing environmental problems is an appropriate way to decrease cement consumption. and would improve some mechanical and durability properties of concrete. Besides, the addition of fibers in concrete mix has long been recognised as a non-conventional mass reinforcement that enhances the mechanical properties of concrete and provides for crack propagation control. A series of experimental studies were carried out to evaluate some mechanical properties of metakaolin cement mortars reinforced with polypropylene fibers. Combind natural and crushed sand, Portland cement, water, metakaolin, polypropylene fibers and superplasticizer were used to construct specimens. In this study, metakaolin as an important pozzolane with percent 10% by volume was replaced to cement in mix design. Polypropylene fibers with percent 0/05%، %1/0and 15/0% were used and then six groups of mortars including control samples were constructed. w/c ratio in concrete mix design was 0.47 constantly. All specimens were demolded after 24 hours, then they were cured in water until were subjected to compression and tension strength. 28 days compression and tension strength, water absorption percent, slump test and unit weight of samples were determined. On the basis of results, use of metakaolin and polypropylene fibers in cement mortars cause to increase compression strength and crack resistance which figures are illustrated. In this article, based upon the results, charts are presented and optimum data are also determined.

compressive and tensile strength, metakaolin, polypropylene fiber