152 / 2022-04-29 17:15:08

Steel fiber mix rate and crack model impact on RC slab analysis model reinforced by top thickening

Thickening its upper surface,Ultra-high strength dense mortar,3-D nonlinear finite element analysis,Steel fiber,Crack model

It is known that reinforced concrete (RC) slabs have degraded over time due to the combined action of fatigue caused by running under a wheel load and the intrusion of chloride-containing water into the RC slab due to the spraying of anti-freezing agents. Horizontal cracks due to corrosion of the reinforced bars and aging deterioration from the upper surface such damage on the upper surface of the RC slab can be seen. One of the repair and reinforcement measures is method of the RC slab thickening its upper surface. However, this method has multiple steps such as repairing the cross section of the slab and adjusting the surface unevenness, and it takes a long time to repair. Furthermore, if amount of the thickening increases, the deadweight will increase, and there is a problem that countermeasure work is required. Therefore, the ultra-high-strength dense mortar can adjust the unevenness and reinforce the 20 mm thin layer, which is difficult with SFRC, so it is effective for short-time construction.



In previous studies, Professor Kazuo Ogaki of the Institute of Technologists conducted a static bending loading test on an RC slab with a thickened top surface of steel fiber reinforced concrete and ultra-high-strength dense mortar and measured its behavior. In this study, we used the data to create an analytical model similar the test piece and analyzed it using a 3-D nonlinear finite element analytical system (Fig. 1). In addition, because of the analytical result, it was considered that the mix rate of steel fibers and the crack model were related to the analysis results, and the analysis was performed by changing the mix rate of steel fibers and the crack model.