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Full-Text Articles in Architecture
Use Of Hybrid Fibers And Shrinkage Mitigating Materials In Scc For Repair Applications, Kamran Aghaee, Kamal H. Khayat
Use Of Hybrid Fibers And Shrinkage Mitigating Materials In Scc For Repair Applications, Kamran Aghaee, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Self-consolidating concrete (SCC) is used to repair structural elements with congested reinforcement or restricted access to placement and consolidation. In addition to adequate flowability, passing ability, filling capacity, and stability, adequate bonding to the substrate and reinforcing bars, low shrinkage and cracking resistance are required for successful repair. This study employs various shrinkage mitigating materials, including expansive agent (EA), coupled use of EA with shrinkage reducing admixture (SRA), and EA with pre-saturated lightweight sand (LWS) to fulfill these requirements. The effect of these materials on the performance of SCC made with a hybrid synthetic (PP) fiber and a hybrid steel-synthetic …
Design And Performance Of Fiber-Reinforced Shrinkage Compensating Eco-Friendly Concrete, Kamran Aghaee, Kamal Khayat
Design And Performance Of Fiber-Reinforced Shrinkage Compensating Eco-Friendly Concrete, Kamran Aghaee, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Eco-Crete is an ecological and economical concrete that benefits from high packing density of solid materials and reduced paste. Eco-Crete can enhance the service life of structures by reducing the risk of shrinkage cracking. In this study, shrinkage mitigating materials included an expansive agent (EA), a shrinkage reducing admixture (SRA), and a lightweight sand (LWS), as well as steel and synthetic fibers were used to minimize the risk of cracking. A total of 35 fiber-reinforced Eco-Crete mixtures were prepared with 350 kg/m3 of cementitious materials and 55 % substitution of fly ash and slag. Key fresh and mechanical properties in …
Effect Of Internal Curing And Shrinkage-Mitigating Materials On Microstructural Characteristics Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat
Effect Of Internal Curing And Shrinkage-Mitigating Materials On Microstructural Characteristics Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Internal curing (IC) and other shrinkage mitigating materials are employed to reduce shrinkage and risk of cracking. This study investigates the efficiency of individual versus combined use of IC and shrinkage mitigating materials on key characteristics of fiber-reinforced mortar (FRM). The investigated mixtures include a 25% pre-saturated lightweight sand (LWS) that is added individually and combined with 10% CaO-based expansive agent (EA) and 2% shrinkage reducing admixture (SRA). This elucidates the synergistic effect of high content IC and EA/SRA on macro- and micro-mechanical characteristics of FRM, especially at the interface of the matrix with fibers. Mechanical properties, microstructural characteristics, and …
Field Implementation And Performance Of Fiber-Reinforced Low-Shrinkage Concrete For Bridge Deck Construction, Ahmed Abdelrazik, Kamal Khayat
Field Implementation And Performance Of Fiber-Reinforced Low-Shrinkage Concrete For Bridge Deck Construction, Ahmed Abdelrazik, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This Paper Reports on the Field Implementation of Fiber-Reinforced Concrete (FRC) Used for Redecking the Two-Span overpass Bridge in Missouri. the Spans Measured 38.4 and 35.05 M in Length. Modeling of the Structural Behavior of the Bridge Replacement Deck Indicated Significantly High Tensile Stresses at Midspan (Up to 45 MPa) Due to the Continuity of the Deck over the Four Precast Main Girders. Redecking of the Bridge and Casting of the Central Diaphragm Were Carried Out Continuously and Necessitated 40 Concrete Truck Deliveries of 252 M3 of FRC. Six Sensor Towers Were Installed in the Bridge Deck to Monitor Variations …
Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat
Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study investigates the effect of individual and combined additions of CaO-based expansive agent (EA), shrinkage reducing admixture (SRA), and super absorbent polymer (SAP) on key characteristics of flowable cement paste mixtures proportioned with a water-to-cement ratio of 0.40. Of special interest is the effectiveness of these admixtures to mitigate shrinkage of cementitious materials for 3D printing. Static and dynamic yield stress, plastic and apparent viscosities, and thixotropy were evaluated at 20-min intervals up to 90 min. Compressive strength development and autogenous shrinkage were also determined. A factorial design approach was developed to evaluate the synergetic effects of the shrinkage …
Benefits And Drawbacks Of Using Multiple Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat
Benefits And Drawbacks Of Using Multiple Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Shrinkage mitigating strategies have been successfully used to prevent concrete cracking. Numerous studies have demonstrated the efficiency of shrinkage mitigating materials (SMM), such as expansive agent (EA), shrinkage reducing admixture (SRA), and superabsorbent polymer (SAP) on reducing shrinkage and cracking; however, few studies have addressed the limitations of using these materials. In addition, the mechanism of negative effect on microstructure and mechanical properties when these materials are used at high contents or in combinations is not well defined. This study investigates the effect of CaO-based EA, SRA, and SAP on compressive strength development, fiber pull-out strength, and shrinkage of fiber-reinforced …
Effect Of Type And Content Of Expansive Agent On Performance Of Fiber-Reinforced Concrete With Adapted Rheology, Ahmed Abdelrazik, Kamal Khayat
Effect Of Type And Content Of Expansive Agent On Performance Of Fiber-Reinforced Concrete With Adapted Rheology, Ahmed Abdelrazik, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
A performance-based mixture design approach was utilized to optimize the binder content and composition for fiber-reinforced super workable concrete (FR-SWC) and fiber-reinforced self-consolidating concrete (FR-SCC). The test parameters included the replacement ratio of the cement by a Class C fly ash (FA), type and content of expansive agent (EA), and total binder content. Hooked-end steel fibers measuring 30 mm in length were used at 0.5% by volume. The investigated concrete was tested for slump flow, modified J-ring, sieve stability, bleeding, visual stability index, air content, unit weight, as well as compressive and splitting tensile strengths. The elastic modulus, autogenous, drying …