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Relationships in ACI 318-14 for calculating the concrete contribution to shear resistance ([V.sub.c]) in reinforced concrete (RC) members (that is, non-prestressed) have been replaced in ACI 318-19 by one general relationship that considers the combined effects of member depth, percentage of longitudinal reinforcement, and the effect of axial stress on predicted shear strength capacity. This new relationship is [V.sub.c] = [(8[[lambda].sub.s][lambda][[[rho].sub.w]].sup.1/3][square root][f'.sub.c] + [N.sub.u]/[6[A.sub.,g]])[b.sub.w]d, where [[lambda].sub.s] is a size effect factor equal to [square root] (2/[1 + d/10])] that accounts for a reduction in shear stress capacity with increasing member depth. The frequently used expression in ACI 318-14, [V.sub.c] = 2[lambda][square root][f.sub.c'bwd], may continue to be used in members containing at least the minimum level of shear reinforcement. The one-way shear provisions for prestressed concrete (PC) members were not changed in this code cycle. The primary basis for the new RC provisions are test results compiled in databases developed and analyzed over the past two decades through a collaboration of Joint ACI-ASCE Committee 445, Shear and Torsion, and the German Committee for Structural Concrete (DAbStb). The process for developing these new provisions included an invitation to the ACI community to suggest new one-way shear design provisions. These suggestions were discussed within Joint ACI-ASCE Committee 445, and then evaluated and modified by ACI Subcommittee 318-E, Section and Member Strength, with consideration of their basis, accuracy, safety, ease-of-use, and range of application. Keywords: building code; database; design; experiments; shear.

Civil structures are prone to dynamic loadings such as strong winds or ground excitations where torsion becomes an ongoing issue. This arises from a lack of coincidence of the center of mass (CM) and rigidity (CR), known as eccentricity. Seismic design codes often introduce two types of eccentricity: inherent (geometric) and accidental. To account for structural or ground motion uncertainties, an assumption-based solution is provided by many code provisions, which considers the accidental eccentricity as a percentage (5% or 10%) of the building length perpendicular to the direction of exposed ground motion. In this study, as an alternative way to the code design parameters, a new design eccentricity formula that considers the frequency ratio (torsional frequency/translation frequency) and an effective radius of gyration to account for torsional irregularity is considered. For the extended validation of the proposed method, eighteen model buildings with six different floor plans were chosen, representing low, medium-height, and high-rise buildings. Each floor plan had model buildings with three, seven, and twelve stories. The buildings were subjected to selected bidirectional earthquake ground motions and had time history analyses performed. The results of the proposed method were compared to code provision methods, obtained using equivalent lateral force procedures, and also to those obtained utilizing the time history analysis results. It was shown that the proposed method was more effective in estimating the impact of torsional eccentricity and provided a better understanding of its impact on structural dynamic characteristics.

The transition from the Uniform Building Code (UBC-97) to the International Building Code (IBC-21) marked a major shift in the definition of seismic hazard. The term “seismic hazard” in the form of peak ground acceleration (PGA) is replaced by spectral acceleration. This paper investigates the effect of using new seismic hazards on the structural performance of reinforced concrete (RC) buildings. It also looks into the financial impact on the capital costs of new buildings. Useful insights are made to understand the structural performance and financial impact of adopting IBC 21 for structural design in contrast to UBC 97. This study was carried out from the perspective of a developing country, Pakistan. Reinforced concrete moment resisting and dual frames are used as the main structural system of a typical 7-story residential building to investigate the aforementioned effect. The frames are assumed to be located in two locations with high and low seismic hazards. The effect on structural performance is investigated via nonlinear pushover analysis. Financial impact is judged mainly through cost estimation for steel and concrete. A detailed discussion is also presented on the seismic design guidelines in both codes.

Despite the intensity of the 2018 Camp Fire, many structures survived in heavily burned areas. Logistic regressions were run to determine which structural and parcel characteristics predicted structure survival using two data sets. The first, CAL FIRE’s Damage Inspections (DINS) dataset, included 14 518 destroyed and 622 partially damaged structures. The second, combining information from the DINS and Defensible Space (DINS+DSPACE) databases, had many more attributes and was better balanced between destroyed (n = 728) and surviving (n = 676) structures, but was much smaller. Several approaches were compared for filtering out records with null values. Results were largely consistent with previously literature, finding that structural hardness factors (e.g. double-paned windows, enclosed eaves, ignition-resistant roofs and siding, no vents, etc.) are important in determining structure survival. Newer structures, built after California’s recent (2005 and 2007) fire safe building code updates, were more likely to survive, as were homes with higher improvement values. Mobile homes were far more likely to be destroyed. The role of fuel mitigation around structures was less conclusive; defensible space clearance had only a weak association with structure survival, although DINS+DSPACE results suggested a slight reduction in risk due to removing leaves and needles from gutters/roofs and keeping surrounding dead grass mowed.

On the anniversary of Haiti's devastating quake, Nicholas Ambraseys and Roger Bilham calculate that 83% of all deaths from building collapse in earthquakes over the past 30 years occurred in countries that are anomalously corrupt.

The first edition of ACT CODE-440.11 was published in September 2022, where some code provisions were either based on limited research or only analytically developed. Therefore, some code provisions, notably shear and development length in footings, are difficult to implement. This study, through a design example, aims at a better understanding of the implications of code provisions in ACT CODE-440.11-22 and compares them with ones in CSA S806-12, thereby highlighting a need for reconsiderations. An example of the footing originally designed with steel reinforcement was taken from the ACI Reinforced Concrete Design Handbook and redesigned with GFRP reinforcement as per ACT CODE-440.11-22 and CSA S806-12. A footing designed as per ACI CODE-440.11-22 requires a thicker concrete cross section to satisfy shear requirements; however, when designed as per CSA S806-12, the required thickness becomes closer to that of the steel-reinforced concrete (RC) footing. The development length required for a glass fiber-reinforced polymer-reinforced concrete (GFRP-RC) cross section designed as per ACI CODE-440.11-22 was 13% and 92% greater than that designed as per CSA S806-12 and ACI 318-19, respectively. Also, the reinforcement area required to meet detailing requirements is 170% higher than that for steel-RC cross section. Based on the outcomes of this study, there appears to be a need for reconsideration of some code provisions in ACI CODE-440.11-22 to make GFRP reinforcement a viable option for RC members.

This paper is an attempt at a better understanding of design provisions of ACI CODE-440.11-22, building code for the design of glass fiber-reinforced polymer (GFRP)-reinforced concrete (RC) columns. Sway and a non-sway column examples originally designed with steel reinforcement were redesigned using GFRP longitudinal bars and ties as per provisions of ACI CODE-440.11-22 to analyze the effect of changing reinforcement type. Columns were designed with both low-modulus ([E.sub.f] = 6500 ksi), and high-modulus ([E.sub.f] = 8700 ksi) GFRP bars. A parametric study was carried out by varying the concrete compressive strength, the cross-section aspect ratio, and the resultant load eccentricity. GFRP-RC columns require larger cross-section dimensions and more reinforcement area than steel-RC columns irrespective of the GFRP elastic modulus when subjected to the same demand. The concrete strength has a significant effect on the dimensions of GFRP-RC columns, and rectangular sections were found to be more efficient than square sections with the same gross concrete area in the presence of moment. GFRP-RC columns subject to high eccentricity loads take advantage of GFRP tensile properties and, thus, are more efficient. Keywords: building code; concrete columns; eccentricity; glass fiber-reinforced polymer (GFRP) reinforcement.

The overdesign of concrete mixtures and substandard concrete acceptance testing practices significantly impact the concrete industry's role in sustainable construction. This study evaluates the impact of overdesign on the sustainability of concrete and embodied carbon emissions at the national and project scales. In addition, this paper reviews quality results from a concrete producer survey; established industry standards and their role in acceptance testing in the building codes; the reliance on proper acceptance testing by the licensed design professional, building code official, and the project owner; and the carbon footprints that result from overdesign of concrete mixtures. In 2020, a field survey conducted on over 100 projects documented Pennsylvania's quality of field testing. Of those surveyed, only 15% of the projects met the testing criteria within the ASTM and building code requirements. As a result, the total overdesign-induced cement consumption is as large as 6.7% of the estimated cement used in the United States. Keywords: building code; carbon footprint; concrete overdesign; life cycle assessment.

PurposeThe building sector contributes one-third of the energy-related carbon dioxide globally. Therefore, framing appropriate energy-related policies for the next decades becomes essential in this scenario to realize the global net-zero goals. The purpose of the proposed study is to evaluate the impact of the widespread adoption of such guidelines in a building community in the context of mixed-mode buildings.Design/methodology/approachThis study decentralizes the theme of improving the energy efficiency of the national building stock in parcels by proposing a community-based hybrid bottom-up modelling approach using urban building energy modelling (UBEM) techniques to analyze the effectiveness of the community-wide implementation of energy conservation guidelines.FindingsIn this study, the UBEM is developed and validated for the 14-building residential community in Mumbai, India, adopting the framework. Employing Energy Conservation Building Code (ECBC) compliance on the UBEM shows an energy use reduction potential of up to 15%. The results also reveal that ECBC compliance is more advantageous considering the effects of climate change.Originality/valueIn developing countries where the availability of existing building stock information is minimal, the proposed study formulates a holistic framework for developing a detailed UBEM for the residential building stock from scratch. A unique method of assessing the actual cooling load of the developed UBEM is presented. A thorough sensitivity analysis approach to investigate the effect of cooling space fraction on the energy consumption of the building stock is presented, which would assist in choosing the appropriate retrofit strategies. The proposed study's outcomes can significantly transform the formulation and validation of appropriate energy policies.

Despite the advancements in digital technologies, the current building design examination practice is 2D and paper-based, and a large number of 2D plans and drawings need to be collated and interpreted to examine if the proposed designs comply with building regulations. Subsequently, it is prone to human errors that make sustainable and consistent design difficult. Although Building Information Modelling (BIM) is recognised as a means to transform the current practice into a more sustainable and productive practice, BIM has rarely been adopted in building design examination. This research aims to identify the reasons for the low uptake of BIM and to examine the feasibility of BIM for building design examination through a focus group interview and workshop. A lack of proper BIM training is identified as the most critical barrier to adopting BIM. Building design examiners indicate that BIM adoption requires consistent efforts with empirical errors, since the existing work processes are not flexible enough to embrace BIM instantly without proper BIM training. An average of three days can be saved by using BIM for a building regulations check. This research revealed that BIM is feasible for building regulation checking, and the low uptake is mainly caused by a lack of awareness of the BIM capabilities.