Application of the one-parameter Bayesian method as the PBMD for concrete mix proportion design

Choi

Int J Concr Struct Mater

et al. 2017

Recently, extreme climate change has been occurring globally not only in the simple form of temperature increases but also in a wide range of extreme climatic events, such as abnormal drought conditions and frequent typhoons. Among these various events, the greatest problem is found in global warming. The earth's temperature has risen since the period of rapid industrial growth in the 1970s, and global warming occurs at the local level of regions and cities as well as the national level. The greenhouse gases that influence global warming include various types of chemical components, such as carbon dioxide (CO 2 ), perfluorocarbons (PFCs), nitrous oxide (N 2 O), and methane (CH 4 ). In addition, climate change is extending the construction period of concrete structures. Whereby increasing related economic losses. Pushing through construction projects without considering climate change is leading to concrete quality deterioration, causing poor constructions and consequently resulting in humans casualties and property damage. In particular, atmospheric CO 2 generates calcium carbonate by reacting with concrete hydration products. This result is reinforcing bar corrosion and concrete durability reduction due to lowered alkalinity. Therefore, in this study, concrete durability performance with respect to carbonation resistance from curing conditions change due to wind speed and sunlight exposure time is evaluated. Based on concrete carbonation resistance data obtained using curing conditions of various wind speed and sunlight exposure time, performance based evaluation (PBE) is performed using the satisfaction curve (SC) developed from the carbonation resistance test results. Using the developed PBE of concrete performance, future concrete performance is predicted based on future climate scenario. Also, the concrete mix design solutions to the concrete performance degradation due to climate change effect is proposed.

Section: Performance Based Evaluationmentioning

confidence: 99%

Performance Based Evaluation of Carbonation Resistance of Concrete According to Various Curing Conditions from Climate Change Effect

Choi

Int J Concr Struct Mater

et al. 2017

“…The levels of required performance are expressed in probabilistic terms as satisfaction percentages. Failure-resistant envelope curves, such as the fragility curve developed by Shinozuka et al (Kim et al 2011;Shinozuka et al 2000aShinozuka et al , 2000b, are used to express structural performance in a probabilistic manner. Using fragility curves, one can determine whether a structure is safe or not as a function of probability ranging from 0 to 100%.…”

Section: Probabilistic Impact Resistant Capacity Evaluationmentioning

confidence: 99%

“…However, a collision from a speeding vehicle causes more serious damage than an earthquake or other dynamic-loading event because of the additional load applied to the structure by the mass acceleration effect (Kernal and Fahri 2011). Transient impact loading is especially detrimental to a column, because the impact loading is extremely fast and the structure does not have time to absorb or transfer the applied load energy through thermal release or stress transfer; thus the structure can sustain severe damage (Kim et al 2011). Therefore, it is critical to systematically evaluate the impact resistance capacity of the column at the design stage.…”

Section: Introductionmentioning

confidence: 99%

“…Using a probabilistic impact resistance capacity evaluation procedure, the most realistic behavioral trends and failure mechanisms of the structure under impact loading can be represented with a probabilistic curve as a function of various structural parameters. This probabilistic approach to determine behavioral trends from complicated and unclear data with multiple parameters has been previously implemented by Shinozuka et al (2000b) and Kim et al (2011) to set up fragility curves and satisfaction curves, respectively, for structural seismic failure evaluation and performance-based concrete mixture design, respectively (Kwon et al 2011). By using the most critical probabilistic behavioral trend curves from impact loading, designers can easily predict the impact resistance capacity of the components exposed to impact collisions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Collision Capacity Evaluation of RC Columns by Impact Simulation and Probabilistic Evaluation

Choi

et al. 2015

ACT

Recently, increasing traffic in urban areas has led to a dramatic increase in collisions between speeding vehicles and structural columns. An impact applies a greater force to a column than its regular static or dynamic load because of the mass acceleration effect of the vehicle. Vehicle impact can cause catastrophic damage to structural columns and ultimately cause them to collapse; therefore, an in-depth study of their structural resistance to vehicle impact is needed. This paper reports the behavior of a reinforced concrete (RC) compression member or column under a lateral impact load. The study quantitatively assessed the columns' resistance capacity and developed an impact-resistance capacity evaluation procedure. Because it is extremely difficult and costly to experimentally perform a parametric study for column impact scenarios, this analytical study was carried out using LS-DYNA, a commercial explicit finite element (FE) analysis program that simulates the effects of a high strain rate from impact or blast loading on structural and material behavior. The parameters used for this case study were cross-section shape variation, impact load angle, axial load magnitude ratio, concrete compressive strength, longitudinal and lateral reinforcement ratios, and slenderness ratio. Using the analysis results, an impact resistance capacity evaluation procedure using a probabilistic approach is proposed.

“…The PBE utilized in this study is a method using a satisfaction curve, which is similar to the Fragility curve method used for seismic performance evaluation [8][9][10][11]. The Bayesian probability theory implemented in the Fragility curve method helps to identify the probable connection between events.…”

Section: Performance Based Evaluation (Pbe) Theorymentioning

confidence: 99%

Performance Based Evaluation of Concrete Strength under Various Curing Conditions to Investigate Climate Change Effects

et al. 2015

Abstract:Recently, the manifestation of global warming-induced climate change has been observed through super typhoons, heavy snowfalls, torrential rains, and extended heat waves. These climate changes have been occurring all over the world and natural disasters have caused severe damage and deterioration of concrete structures and infrastructure. In an effort to deal with these problems due to extreme and abnormal climate changes, studies have been conducted to develop construction technologies and design guidelines. Nevertheless, study results applicable to construction sites continue to be ineffective and insufficient. Therefore, this study proposes ways to cope with climate change by considering the effect of concrete curing condition variations on concrete material performance. More specifically, the 3-, 7-and 28-day compressive and split tensile strength properties of concrete mix cured under various climatic factors including temperature, relative humidity, wind speed, and sunlight exposure time were evaluated to determine whether the concrete meets the current design requirements. Thereafter, a performance based evaluation (PBE) was performed using satisfaction probabilities based on the test values to understand the problems associated with the current mix proportion design practice and to identify countermeasures to deal with climate change-induced curing conditions. OPEN ACCESSSustainability 2015, 7 10053