Crack Opening Behavior of Concrete Reinforced with High Strength Reinforcing Steel

The degradation of the load-bearing capacity of reinforced concrete beams due to corrosion has a profoundly negative impact on the structural safety and integrity of a structure. The literature is limited with regard to models of bond characteristics that relate to the reinforcement corrosion percentage. In this study, uniaxial tensile tests were conducted on specimens with irregular corrosion of their reinforced concrete. The development of cracks in the corroded area was found to be dependent on the level of corrosion, and transverse cracks developed due to tensile loading. Based on this crack development, the average stress versus deformation in the rebar and concrete could be determined experimentally and numerically. The results, determined via finite element analysis, were calibrated using the experimental results. In addition, bond elements for reinforced concrete with corrosion are proposed in this paper along with a relationship between the shear stiffness and corrosion level of rebar.

Section: Bond Strength and Slipmentioning

confidence: 99%

Evaluation of Bond Properties of Reinforced Concrete with Corroded Reinforcement by Uniaxial Tension Testing

Kim

Choi

Sangchun

et al. 2016

“…Soltani et al (2013) and Harries et al (2012) also demonstrated that 2/3 f y can be taken as the stress in the steel reinforcements at the service loads (f s ) for the high yield strength steels even up to 827 MPa (120,000 psi). Therefore, it is considered that the allowable stress increase of the prestressing steel under the service load (Df ps,allow ) can be increased from 250 to 350 MPa in the partial PSC members reinforced with 550 MPa nonprestressed steel.…”

Section: Proposed Approaches 61 Simple Checking Of the Net Tensile Smentioning

confidence: 99%

Control of Tensile Stress in Prestressed Concrete Members Under Service Loads

Lee¹,

Han²,

Joo³

et al. 2018

In current design codes, crack control design criterion for prestressed concrete (PSC) members is stricter than conventional reinforced concrete (RC) members. In particular, it is stipulated that the net tensile stress of prestressing strands should be controlled under 250 MPa in the serviceability design of PSC members belonging to the Class C category section that is expected to be cracked due to flexure under service load conditions as defined in ACI318 code. Thus, the cracked section analysis is essentially required to estimate the tensile stress of the prestressing strands under the service loads, which requires very complex iterative calculations, thereby causing many difficulties in the applications of the Class C PSC members in practice. Thus, this study proposed a simple method to estimate the net tensile stress of the prestressing strands (Df ps ) under the service load conditions, and also provided a summary table to be used for checking whether the net tensile stress (Df ps ) exceeds the stress limit (250 or 350 MPa) with respect to the magnitude of effective prestress (f se ).

“…ElSafty and Abdel-Mohti (2013) found that deflection is an important parameter affecting cracking. Reinforcing steel characteristics (including bar size, spacing, cover, and other details) can affect the extent of bridge deck cracking as well as crack widths and patterns (Soltani et al 2013).…”

Section: Background Information On Cracking In Bridge Decksmentioning

confidence: 99%

Field-Observed Cracking of Paired Lightweight and Normalweight Concrete Bridge Decks

Cavalline

Calamusa

Kitts

et al. 2017

Research has suggested that conventional lightweight concrete can offer durability advantages due to reduced cracking tendency. Although a number of publications exist providing the results of laboratory-based studies on the durability performance of lightweight concrete (with lightweight coarse aggregate) and internally cured concrete (using prewetted lightweight fine aggregate), far fewer field studies of durability performance of conventional lightweight concrete bridge decks in service have been performed. This study was commissioned to provide insight to a highway agency on whether enhanced durability performance, and therefore reduced maintenance and longer lifecycles, could be anticipated from existing lightweight concrete bridge decks that were not intentionally internally cured. To facilitate performance comparison, each lightweight bridge deck selected for inclusion in this study was paired with a companion normalweight bridge deck on a bridge of similar structural type, deck thickness, and geometric configuration, with similar age, traffic, and environmental exposure. The field-observed cracking of the decks was recorded and evaluated, and crack densities for transverse, longitudinal, and pattern cracking of the normalweight and lightweight deck in each pair were compared. Although some trends linking crack prevalence to geographic location, traffic, and age were observed, a distinct difference between the cracking present in the paired lightweight and normalweight bridge decks included in this study was not readily evident. Statistical analysis using analysis of covariance (ANCOVA) to adjust for age and traffic influence did not indicate that the type of concrete deck (lightweight or normalweight) is a statistically significant factor in the observed cracking. Therefore, for these service environments, lightweight decks did not consistently demonstrate reduced cracking.