Response of Reinforced Engineered Cementitious Composite Flexural Members Subjected to Various Cyclic Deformation Histories

Engineered Cementitious Composite (ECC) is a class of High-Performance Fiber-Reinforced Cement based Composite (HPFRCC) materials that has been developed and tailored over the last several decades. A composite material made from mortar and short, randomly disbursed fibers, ECC has enhanced tensile and compressive properties, in particular ductility, when compared to typical concrete. These improved material properties lend ECC to multiple uses in the built environment with the potential to increase structural performance and durability, and limit infrastructure maintenance and life-cycle cost.

When reinforced with deformed steel bars, reinforced ECC and other reinforced HPFRCC components have enhanced seismic performance of structural components and systems such as coupling beams, steel moment frames with infill panels, joints, columns, and beams. But assessing seismic performance is complex, in part, because the deformations the next earthquake will induce on a structure are unknown. Based on the abundance of recorded ground motions from past earthquakes, it is clear that all ground motions do not induce the same deformation in structures.

This dissertation provides the first insights of steel reinforced ECC flexural member response under different deformation histories through a variety of quasi-static laboratory experiments and numerical simulations. Because a large pulse in a deformation history may cause fiber failure within the ECC material and alter the response on a material level, deformation histories that contain initial pulses are of particular interest. Being able to assess the structural response of reinforced ECC components due to a range of possible deformation histories is important if the material is to become widely adopted.