Browsing by Subject "Fiber reinforced concrete"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Comparison of Performances of Structural Fibers and Development of a Specification for Using Them in Thin Concrete Overlays(Minnesota Department of Transportation, 2018-08) Barman, Manik; Hansen, BryceStructural fibers improve the long-term performance of concrete pavements and overlays and potentially are useful to reduce the slab thickness. These fibers are available in different parent material compositions, stiffness, shapes, and aspect ratios. The main objective of this study was to characterize the post-crack flexural and joint performance of fiber reinforced concrete to develop a specification for the selection of structural fibers for concrete overlays and/or pavements. The study included a literature review, an online survey, and a large-scale laboratory testing. It was found that the majority (almost 94%) of the FRC overlays in this country were constructed with structural synthetic fibers, which provided equal or better performance than projects using the steel fibers. In the laboratory study, a total of 43 different mixes were prepared with 11 different types of fibers. Fiber dosage, stiffness, and geometry significantly influenced the residual strength ratio (RSR) and residual strength (RS). In general, embossed, twisted, and crimped fibers performed better on average than straight-flat synthetic fibers when the comparison was made in terms of RSR or RS. From the joint performance testing, it was found that fibers can greatly improve the performance of the pavement with respect to load transfer efficiency (LTE), differential displacement, and differential joint energy dissipation. The findings from this were used to recommend the target ranges post-crack flexural performance, and joint performance parametersItem Establishing Fresh Properties of Fiber Reinforced Concrete for Performance Engineered Mixture (PEM)(Minnesota Department of Transportation, 2022-06) Barman, Manik; Kamara, Alieu; Janson, AustinThe addition of macro or structural fibers into concrete enhances its post-cracking performance. The objective of this study was to conduct a laboratory investigation to determine the influence of structural fibers on the fresh concrete test parameters (Super air meter (SAM) number, V-Kelly index, and Box test rating) recommended for the performance engineered mixture (PEM) procedure. As many as fifty-seven different concrete mixes were designed and prepared, varying fiber types and dosages, aggregate types, and air contents of the concrete. Various fresh and hardened concrete tests were conducted on each of the mixes, and the results were used to determine the influence of the structural fibers on the fresh and hardened concrete properties. The study recommended the allowable range of the SAM number and provided necessary guidance on the box test rating and V-Kelly index for the fiber-reinforced concrete mixtures to be designed as per the PEM procedure.