Michele Barbato

University of California, Davis | UCD · Department of Civil and Environmental Engineering

This study evaluated the properties of sugarcane bagasse ash (SCBA) obtained from different production processes for use as partial replacement of cement: (1) minimally post-processed (MP) SCBA, obtained by sieving and grinding SCBA from Louisiana’s sugarcane field production; (2) fully post-processed (FP) SCBA, obtained by sieving, further burning...

Wildfire frequency has increased in the Western US over recent decades, driven by climate change and a legacy of forest management practices. Consequently, human structures, health, and life are increasingly at risk due to wildfires. Furthermore, wildfire smoke presents a growing hazard for regional and national air quality. In response, many scien...

The increasing number and severity of wildfires is negatively impacting air quality for millions of California residents each year. Community exposure to PM2.5 in two main population centers (San Francisco Bay area and Los Angeles County area) was assessed using the low-cost PurpleAir sensor network for the record-setting 2020 California wildfire s...

This study investigates the effects of high temperatures on the mechanical strength of compressed and stabilized earth blocks (CSEBs). 60 CSEB were manufactured by compacting a mixture of natural soil (sandy loam), water, and 9% (by weight) Type-II ordinary Portland cement using a manually-operated CINVA-RAM compression machine. The CSEBs were test...

Earth block masonry (EBM) is attracting interest as an affordable and sustainable alternative to other mainstream materials and systems for low-rise buildings. However, most of the research available in the literature focuses on characterizing the mechanical properties of earth blocks, whereas only a few studies investigate the structural behavior...

Finite element (FE) simplified micro-modeling techniques are commonly used to investigate and predict the mechanical behavior of masonry structures because they provide a good compromise between accuracy and computational cost. These FE techniques generally discretize masonry structural elements into expanded masonry units and zero-thickness interf...

This study investigated the feasibility of using high contents of post-processed sugarcane bagasse ash (PBA) as a partial replacement of cement for the development of Engineered cementitious composites (ECCs) with low amounts (1.5% by volume) of non-oil-coated polyvinyl alcohol (PVA) fibers. PBA was prepared by sieving, burning, and grinding raw su...

This paper investigates the effects of sugarcane bagasse fibers (SCBFs) on the mechanical strength and durability properties of compressed and stabilized earth blocks (CSEBs). CSEBs were fabricated using natural soil and SCBFs, collected from Lakeland, LA, with a manually operated compression machine. Nine different soil mix compositions containing...

The potential for cascading disaster risks, especially in the context of extreme events, is well documented. However, concerted efforts to address cascading disaster risks in planning and local government decision-making have lagged. This paper explores the institutional drivers of planning for an emblematic form of cascading risk – wildfire-induce...

Numerous rockfall incidents involving infrastructure damage and loss of life have been reported along roads in mountainous terrain. Previous studies have used quantitative risk assessment approaches to identify the level of rockfall risk. However, appropriate quantitative indicators that are able to describe time-varying risk have not yet been deve...

Coastal areas have environmentally and economically important roles but tend have weak soft ground, which is often vulnerable by waves and unsuitable for coastal construction, such as ports and waterfront areas. Hence, this soft ground, which usually contains large amounts of clays, needs to be ameliorated by using appropriate soil improvement tech...

The complex shape dependence of wind pressure’s peak factors (PFs) makes it difficult to predict their values for all geometries by using analytical models. Thus, experimental studies are necessary to validate available or new analytical models for each specific shape and geometry. Very little information is available in the literature for the hype...

The use of raw sugarcane bagasse ash (SCBA) as sand replacement in the production of engineered cementitious composites (ECCs) can improve its cost-effectiveness and practicality. A recent study by the authors showed that the use of raw SCBA as a replacement to sand in ECC mixtures substantially enhances the tensile ductility and provides mild impr...

Hurricanes are among the most destructive and costly extreme weather events. The intensity of future hurricanes is generally expected to increase due to climate change effects. In this work, a simulation method based on a comprehensive statistical analysis of historical data is developed to account for the changes in climatological conditions and t...

This study aims to evaluate the effect of the incorporation of sugarcane bagasse ash sand (BS) as a partial replacement to silica sand on the properties of engineered cementitious composite (ECC). ECC mixtures with different replacement levels of sand (including 0%, 25%, and 50% by volume) with BS were produced. To characterize the mechanical prope...

This paper investigates the mechanical properties under laboratory and field conditions of a concrete-like blend made of fluorogypsum (FG), fly ash, and Portland cement for artificial reef construction, which is referred to as FG-based blend. The 28-day compressive strength and relative volumetric expansion of the FG-based blend were statistically...

Typically, the compressive response of compressed and stabilized earth block (CSEB) specimens is characterized by performing uniaxial compression tests on blocks or block portions. However, the effect of specimen geometry and shape on the compressive strength and stress-strain response are not yet well understood. This paper presents the results of...

This study investigates the use of recycled soil obtained by crushing earth blocks as replacement of natural soil in the production of the compressed and stabilized earth blocks (CSEBs). An experimental campaign was conducted to assess the behavior of CSEBs produced using different levels of recycled soil. The prototype CSEB (referred to as N-CSEB)...

The US Gulf Coast is often struck by severe hurricane events. These natural events can cause massive economic and life losses. Based on the projected increase in global sea surface temperature and in population residing along the US Gulf Coast region, the intensity of future hurricanes is expected to increase with time in conjunction with an increa...

A new interface element's constitutive model is proposed in this study for analyzing masonry using simplified micro-modeling (SMM) approach, in which mortar and two unit-mortar interfaces are lumped into a zero-thickness joint (modeled using an interface element) between expanded masonry units. The new model is capable of simulating tension crackin...

Confinement of reinforced concrete (RC) piers generally has a beneficial effect on both the compressive strength and the ductility of the confined member. Thus, externally-bonded fiber-reinforced polymer (FRP) wrapping is often used as a retrofit technique for bridge piers when additional compressive strength is needed. This study employs finite el...

Previous studies have shown the possibility of successful implementation of Sugarcane Bagasse Ash (SCBA) as a Supplementary Cementitious Material (SCM) in concrete production. However, its use has been constrained in the construction industry due to lack of a suitable largescale processing methodology of SCBA. In this study, the pozzolanic performa...

This paper presents a confined concrete material constitutive model for use in finite-element analysis, which is able to model accurately the combined confinement effect of fiber-reinforced polymers (FRP) and internal steel reinforcement on the structural monotonic, cyclic, and/or dynamic response of reinforced concrete (RC) columns confined with e...

This paper develops a new low-cost construction material made of pH-adjusted fluorogypsum, class C fly ash, and type II Portland cement. The proposed fluorogypsum-based blend is durable in water and has a lower weight and lower cost than ordinary concrete. A preliminary investigation of strength and durability properties of this new construction ma...

The sulfate release from solidified/stabilized fluorogypsum was measured to develop the effective diffusion coefficients (De) as a parameter to assess the dissolution potential in aquatic applications. Specimens from 11 compositions consisting of 60-90% pH-adjusted fluorogypsum (pFG), 2-10% Type I/II portland cement (PC), and 0-38% Class C fly ash...

Compressed and stabilized earth blocks (CSEBs) are typically manufactured through one-side compaction. The resulting soil matrix-hydrated cement microstructure is heterogeneous, posing the question of whether CSEB materials can be considered homogeneous and isotropic for the purpose of analysis of CSEB structures, similar to rammed earth. As earth...

This paper presents a newly developed constitutive model for interface elements, which can be used to model and predict the local and global response of masonry walls by using a simplified micro-modeling (SMM) approach within the finite element method (FEM) framework. An unreinforced masonry shear wall, for which well-documented experimental result...

Objective: Southern Louisiana is currently under great pressure to increase the quantity of resilient and affordable housing available within its local communities. Can earthen building mediums traditionally used in hot dry climates be re-appropriated for use in hot wet climates to help address this need? Methodology: In our current period of cli...

Compressed and stabilized earth block (CSEB) structural systems represent a sustainable low-cost alternative to other construction systems that are common in industrialized countries. The wide availability of suitable soils makes these structural systems attractive for building affordable housing worldwide. Currently, CSEB construction in the USA i...

This study investigates the mechanical and durability properties of blends made of fluorogypsum (FG) with the pH adjusted by using controlled amounts of circulating fluidized bed combustion ash (CFBCA) and denoted as C-FG, class C fly ash (FA), and type II Portland cement (PC). A series of pH tests was conducted on samples of C-FG to develop an ana...

This paper provides perspectives on multihazard engineering in the contemporary structural engineering context in order to frame the breadth and multiple dimensions it encompasses, to summarize recent activities on selected relevant topics, and to highlight possible future directions in research and implementations. A comprehensive overview of all...

Compressed and stabilized earth block (CSEB) structural systems are becoming popular due to their low cost, low carbon footprint, use of indigenous materials, and inherent simplicity. CSEB structural systems are characterized by higher thermal insulation, better humidity control, and smaller embodied energy than fired clay masonry. Currently, CSEBs...

Compressed and stabilized earth blocks (CSEBs) are manufactured by compressing a mixture of soil, water, and a stabilizer. This process may result in non-uniform physical and mechanical properties, posing the question of whether CSEBs can be regarded as isotropic for the purpose of analysis and design of earth masonry structures. In the research re...

This research aims to develop a concrete-like material for underwater construction applications by using fluorogypsum (FG, an industrial by-product of hydrofluoric acid production), class C fly ash, and type II Portland cement. Two Response Surface Models (RSMs) were derived based on compressive strength tests and expansion measurements on FG-based...

The special collection on Recent Advances in Assessment and Mitigation of Multiple Hazards is available in the ASCE Library (http://ascelibrary.org/page/jsendh/assessment_mitigation_multiple _hazards). Recent events, such as the 2011 Tohoku earthquake and Hurricane Sandy in 2012, have highlighted the potentially catastrophic effects that multiple...

Hurricanes represent multihazard events that include wind, windborne debris, storm surge, and rainfall hazards. Conventional risk analysis does not consider the interaction between these multiple hazards and treats each risk source as statistically independent of other hazards. In this paper, the effects of multihazard interaction on the performanc...

The seismic-induced pounding between adjacent buildings is an undesirable event that can cause major damage and even structural collapse for structures with inadequate separation distance. This issue is particularly important in metropolitan areas, where the land space is limited and expensive. In order to minimize the pounding risk, existing desig...

Earthquake ground motion records are nonstationary in both amplitude and frequency content. However, the latter nonstationarity is typically neglected mainly for the sake of mathematical simplicity. To study the stochastic effects of the time-varying frequency content of earthquake ground motions on the seismic response of structural systems, a pai...

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal. © 2016 This work...

Hurricanes are among the most costly natural hazards affecting communities worldwide. The landfall of a hurricane involves different hazard sources (i.e., wind, wind-borne debris, flood, and rain) that interact to generate the hazard scenario for a given structure. Thus, hurricanes can be viewed and must be analyzed as multi-hazard scenarios. In th...

Earthquake-induced pounding of adjacent structures can cause severe structural damage and advanced probabilistic approaches are needed to obtain a reliable estimate of the risk of impact. This study aims to develop an efficient and accurate probabilistic seismic demand model (PSDM) for pounding risk assessment between adjacent buildings, which is s...

In recent years, severe hurricanes have caused enormous economic losses for society and placed tremendous burden on the insurance industry. As the number of residential buildings in hurricane prone regions continues to rise, hurricane hazard mitigation is of paramount importance for residential buildings. Although different retrofit measures are av...

This paper presents an efficient reliability-based methodology for the seismic design of viscous/viscoelastic dissipative devices in independent and/or coupled buildings. The proposed methodology is consistent with modern performance-based earthquake engineering frameworks and explicitly considers the uncertainties affecting the seismic input and t...

In recent years, severe hurricanes have caused enormous economic losses for the society and placed a tremendous burden on the insurance industry. Although different retrofit measures can be used to mitigate hurricane damage and reduce the associated social and economic losses, it is a challenge to choose the most cost effective one. In the case of...

Hurricanes are among the most costly natural hazards affecting communities worldwide. The landfall of a hurricane involves different hazard sources (i.e., wind, windborne debris, flood, and rain) that interact to generate the hazard scenario for a given structure. Thus, hurricanes can be viewed and must be analyzed as multi-hazard scenarios. In thi...

This paper presents the derivation of experimental fragility curves for windborne debris (WBD) impact risk assessment of aluminum storm panels within a recently developed performance-based hurricane engineering (PBHE) framework. By using a pneumatic wind cannon, rod-type WBDs were fired at aluminum storm panels to evaluate the effects of WBD impact...

This paper presents a frame finite element (FE) that is able to accurately estimate the load-carrying capacity and ductility of reinforced concrete (RC) circular columns confined with externally-bonded fiber-reinforced polymers (FRP). This frame FE can model collapse mechanisms due to concrete crushing, reinforcement steel yielding, and FRP rupture...

This paper presents closed-form solutions for the nongeometric spectral characteristics of nonstationary stochastic processes representing the response of linear elastic structural models subjected to fully nonstationary excitation processes. These spectral characteristics provide a complete description of the nonstationary stochastic processes rep...

This paper presents the results of recent ground shock experiments conducted by the U.S. Army Engineer Research and Development Center to further investigate the adequacy of the coupling factor approach to shallow-buried or near-surface detonations. Comparisons between these recent experimental results and results of numerical simulations of the gr...

This paper employs a methodology for probabilistic response analysis based on the first-order second moment (FOSM) method in conjunction with response sensitivity computation through the direct differentiation method (DDM), to study the variability of the structural response of steel-concrete composite (SCC) beams. This methodology is applied to co...

Existing design procedures for determining the separation distance between adjacent buildings subjected to seismic pounding risk are based on approximations of the buildings' peak relative displacement. These procedures are characterized by unknown safety levels and thus are not suitable for use within a performance-based earthquake engineering fra...

This study aims to develop a Probabilistic Seismic Demand Model (PSDM) for pounding risk assessment suitable for use within modern performance-based design frameworks. In developing a PSDM, different choices can be made regarding the intensity measures (IMs) to be used, the record selection, the analysis technique applied for estimating the system...

Seismic pounding can induce severe damage and losses in buildings. The corresponding risk is particularly relevant in densely inhabited metropolitan areas, due to the inadequate clearance between buildings. In order to mitigate the seismic pounding risk, building codes provide simplified procedures for determining the minimum separation distance be...

A c c e p t e d M a n u s c r i p t N o t C o p y e d i t e d ABSTRACT Considerable interest has been directed in recent years toward the use of self-healing materials in concrete. The concept of microcapsule healing is based on a healing agent being encapsulated and embedded in the concrete. The objective of this study was to evaluate the effects...

This paper introduces a probabilistic Performance Based Hurricane Engineering (PBHE) framework for risk assessment based on the total probability theorem. This methodology disaggregates the risk assessment analysis into independent elementary components, namely hazard analysis, structural characterization, interaction analysis, structural analysis,...

This paper presents a methodology for developing windborne debris (WBD) impact fragility curves for building envelope components (BECs) by using stochastic finite element (FE) models. These fragility curves provide the probabilistic description of the impact resistance of BECs subject to an impact event described by an appropriate intensity measure...

Timber-concrete composite beams are an increasingly common design solution for medium-to-long span floors in new buildings. Thus, there is a significant need for accurate models and analysis tools to predict the response and performance of timber-concrete composite beams. In this paper, a nonlinear finite-element (FE) frame model with deformable sh...

Earthquake ground motion excitation can induce pounding in adjacent buildings with inadequate separation distance. The corresponding risk is particularly relevant in densely inhabited metropolitan areas, due to the usually limited separation distance between adjacent buildings. Existing procedures to determine a minimum separation distance needed t...

This paper uses a fully probabilistic approach to investigate the seismic response of multispan continuous bridges with dissipative piers and a steel–concrete composite (SCC) deck, the motion of which is transversally restrained at the abutments. This bridge typology is characterized by complex dual load path behavior in the transverse direction, w...

The current highway bridge design in the United States follows the AASHTO-LRFD specifications, which prescribe a dynamic load allowance, IM, of 0.33 for the dynamic effect of truck/tandem loading. Studies have shown that the IM value prescribed by the LRFD code may underestimate this dynamic effect under poor road surface conditions (RSCs). One rea...

This paper presents new closed-form analytical approximations to the first-passage problem in structural reliability by using the exact closed-form solutions for the spectral characteristics of nonstationary random processes. The first-passage problem applied to a structural system possibly with random parameters and subjected to stochastic loading...

This paper proposes an innovative fully probabilistic Performance-Based Hurricane Engineering (PBHE) approach for risk assessment and design of structural systems located in hurricane-prone regions. The methodology is based on the Total Probability Theorem and disaggregates the risk assessment analysis into independent elementary components, namely...

In this work, the spectral characteristics of non-stationary random processes are applied to the time-variant first-passage problem in structural reliability. The first-passage problem consists in computing the probability of a response quantity exceeding a deterministic threshold in a given interval of time when the parameters defining the structu...