Experimental and numerical simulation of corrosion induced expansive pressure on concrete cover

Abstract

In this research, an investigation was carried out through experimentation and numerical modeling to evaluate the cracking pressure induced due to corrosion of reinforcement for different cover thicknesses, grades of concrete and bar locations. The model was also used to determine the patterns of crack for a different number of bars and the effect of bar diameter on cracking pressure. The critical pressure was measured experimentally by applying hydraulic pressure through a hole in concrete cubes of 150 mm. Abaqus 6.14 was used as a modeling platform. From the experimentation and numerical modeling, it was found that with the increase of cover thickness the critical pressure was increased irrespective of bar locations. A lower cracking pressure was observed for corner bar with respect to the sidebar. On the other hand, with the increase in bar diameter, a decrease in cracking pressure was observed. The critical pressure observed was also increased with higher grades of concrete. For corner bars with cover thickness 37.5 mm, the critical pressure was found as 6-10 MPa and it increased up to 17 MPa for the cover thickness of 64 mm for different grades of concrete. On the other hand, for other bar location with the cover thickness of 37.5 mm and 64 mm, the pressure required to initiate crack was about 7.6 MPa and 14.8 MPa, respectively, for C20 grade concrete.

Characterization of Impressed Current Technique to Model Corrosion of Reinforcement in Concrete

“…Reinforcing steel remains in stable passive state at very high pH as shown in Figure 1. Since the pH of concrete pore solutions is very high (Austin et al, 2004;Nossoni and Harichandran, 2012;Morshed, 2020, Shakib and, concretes give a good protection against corrosion (Bazant, 1979;Broomfield, 2006;Maaddawy and Soudki, 2003). On the other hand, a passive layer is formed due to hydration of cement on the steel surface, which also protects it from corrosion.…”

Simulation of reinforced concrete beam retrofitted with steel angles subjected to flexure

“…Adverse weathering conditions, such as corrosion of reinforcement due to salinity as well as carbon dioxide, deterioration of concrete due to sulphates and alkaline solutions, wear and abrasion due to tidal effect, successive freeze-thaw effect, etc., deteriorate the structures (Bažant, 1979; Mundra et al. , 2017; Neville, 2011; Shakib et al. , 2020; Shakib and Morshed, 2019; Val et al.…”

“…However, these structures lose some strength due to their normal use over time (Neville, 2011). Adverse weathering conditions, such as corrosion of reinforcement due to salinity as well as carbon dioxide, deterioration of concrete due to sulphates and alkaline solutions, wear and abrasion due to tidal effect, successive freeze-thaw effect, etc., deteriorate the structures (Ba zant, 1979;Mundra et al, 2017;Neville, 2011;Shakib et al, 2020;Shakib and Morshed, 2019;Val et al, 2009). Higher temperature exposure due to fire is another cause to deteriorate the reinforced concrete (RC) structures (Mahmud et al, 2021).…”