Building Code Research Articles

Mechanical performance of coal ash based interlocking bricks wall panel: A sustainable and viable solution

The use of interlocking brick incorporating waste coal ash (CA) in masonry construction is an innovative, sustainable and viable solution to address the consequences associated with burnt clay bricks. In this research, the main focus was to study the double interlocking brick incorporating CA for its potential use in masonry construction. The studied dosages of CA were 30 %, 35 %, 40 %, 45 %, 50 % and 55 %. Cement was varied between 5 % and 30 % in order to make the total binder (cement and CA) contents equal to 60 %. Moreover, wall panels using developed interlocking bricks were casted and tested for out-of-plane loading. It was observed that the incorporation of higher dosage of CA decreased the compressive strength owing to porous nature of used CA. However, interlocking bricks having 30 % of CA exhibited compressive strength higher than 8 MPa, satisfying the local building code requirement. Higher water absorption was observed for interlocking bricks having higher dosage of CA compared to identical bricks with lower CA. Interlocking bricks exhibited higher shear strength due to mechanical anchorage provided by the keys and notches in comparison with the conventional bricks. Maximum double key shear strength of 2.34 MPa was observed for developed interlock bricks incorporating 30 % of CA. Interlocking brick wall panel exhibited flexural strength of 1.05 MPa compared to 0.81 MPa for wall panel constructed using conventional burnt clay brick. Higher flexural strength of interlock CA based brick wall panel was due to the higher mechanical anchorage provided by the projected keys and grooves in between various courses of the wall panel. The cracking patterns of interlocking brick wall panel exhibited diagonal failure rather than the horizontal slide shear failure observed for conventional burnt clay brick wall panel. The experimental cracking load values were comparable with the theoretically predicted cracking loads for the tested wall panels. This study highlights the use of water cured interlocking brick incorporating waste CA for eco-friendly and economical construction leading to avoid the devasting effects of manufacturing process of conventional burnt clay bricks and deposition issues of CA. Moreover, this study motivates the construction stakeholders to employ double interlocking bricks of similar conventional size bricks to be used in a similar manner for masonry construction.

Sustainability of cool and black roofs with high initial construction moisture

This study examines the sustainability of roofs subjected to hot climate of Phoenix and cold climate of Montréal by using a validated numerical model that simultaneously solves the heat, air, and moisture equations. In many situations, the initial conditions needed to solve these equations are not available. This paper provides a procedure for conducting energy and moisture modelling so that using different initial conditions would result in no effect on the final results of roof performance. Additionally, the study focuses on: (a) assessing the moisture performance of black and cool roofs in case of using material layer with high initial construction moisture content (Fibreboard, FB), (b) identifying the time period needed so that the moisture content would reach acceptable limit by the building codes, and (c) determining the amount of energy savings as a result of using sustainable cool roofs instead of black roofs. The results show that the moisture content in the FB decreases to permissible levels after 92.6 days for black roof and 175.7 days for cool roof in Phoenix, while in Montréal, it takes 238.6 days and 1597 days, respectively. The effect of using different initial condition vanishes after 196 days for Phoenix’s black roof, 583 days for its cool roof, and 1247 days for Montréal’s black roof and 4590 days for its cool roof. Mold is detected in FB. In Phoenix, mold disappears after 379 days for black roof and 479 days for cool roof, whereas in Montréal, it takes 708 days and 3143 days, respectively.

From private to public and back? Kyoto's cityscape councils and the urban commons

AbstractScholarly and public debate on the urban commons is burgeoning, but building exteriors and the cityscape these constitute are surprisingly absent from it, despite their considerable significance for and impact on residents and visitors. After reflecting on the cityscape as a commons, the article turns to Kyoto, the former capital of Japan and acclaimed stronghold of history and tradition. Decades of conflict about the built environment led to a new building code in 2007 that continues to enjoy broad support. Details of building design, however, are now left to ‘local cityscape councils’, volunteer bodies that discuss construction plans with developers. Officially, local amateurs meet non‐local professionals here, but ethnographic fieldwork in 2019/20 revealed that both technical expertise and Kyoto ties are present on both sides. State representatives are also less absent than officially proclaimed. This case demonstrates that mixed management of the urban commons by the state and civil society can lead to amicable solutions that rise above vested interests, so that state involvement and ‘commoning’ should not be posited as mutually exclusive.

Seismic Fragility Analysis of a Multi-Tower Super High-Rise Building Under Near-Fault Ground Motions

ABSTRACT Earthquake damage to engineering structures often occur in near-fault areas. Near-fault ground motion is characterized by high-energy velocity pulses, long action period, and strong destructiveness. This paper forces on the seismic analysis of a multi-tower super high-rise building that subjected to near-fault ground motions. The interactions between each tower makes the internal forces and dynamic responses much complex and totally different from single-tower super high-rise buildings. However, currently, multi-tower buildings in China are usually regarded as multiple single-tower buildings, and then separately designed based on the relevant provisions in seismic code for single-tower buildings. The mutual influence between the towers is almost not taken into account. Seismic response history analysis was carried on a three-tower super high-rise building using finite element method. Various near-fault and far-fault ground motions and high-energy velocity pulses were used as inputs. Through calculation of inter-story drift ratio and maximum displacement, the quantitative seismic fragility analysis was conducted for the main tower and sub-tower structures. The results show that the responses from near-fault ground motions to the structure are much greater than those from far-fault ground motions. The damage probabilities of various damage levels for near-fault ground motions are 12.5% higher than far-fault ground motions averagely. A further analysis reveals that the velocity pulses are the main factor causing structural damage in near-fault ground motions.

Seismic performance and cost comparison of RC moment resisting and dual frames using UBC 97 and IBC 2021

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.

A Comparative Study of Fire Code Classifications of Building Materials

Whether noncombustible or combustible construction is used, the presence of combustible materials is likely to be used for various reasons, such as interior finishes, flooring, and insulation. Consequently, how regulations consider the degree of combustibility in their fire classifications will influence the level of fire safety provided in these buildings and the exchanges between all actors in the construction sector. In North America, the regulation of combustibility is primarily governed by surface flame spread assessed through the Steiner tunnel test. While there is a growing prevalence of calorimetric methods globally, their incorporation into North American building codes remains notably limited. Based on ISO 5660-1 cone calorimeter test results of twenty commercially available North American building materials, a comparative study was conducted between the Canadian flame spread classification and the classifications in Japan, New Zealand and the European Union (Euroclass). The tests and their limitations are described herein, as well as the conceptual frameworks. The results suggest that as materials’ combustibility levels increase, the level of agreement between classifications decreases and remains binary. The choice between the material and system scales is crucial for determining the effective development and implementation of regulations.

Noise control for curtain wall construction in residential buildings - a retrofit solution

In modern high-rise residential buildings, designers and architects utilize curtain wall construction either for the entire building or a portion of the building to achieve the desired visual impact in an urban setting. This poses significant challenges to satisfy the building code acoustical requirement (e,g., sound transmission class) between residential suites on adjacent floors. Apparent sound transmission class tests were completed after the curtain wall system was installed and concluded non-compliance with the Ontario Building Code acoustical requirement. A retrofit noise mitigation option was proposed and implemented. The ASTC field test was repeated and concluded compliance with the building code acoustical requirement.

Integrating Sonic Pulse Velocity Tests with Masonry Classification for Heritage Conservation: An Insight from On-Site Diagnostic Campaigns

ABSTRACT The preservation of architectural heritage relies on a comprehensive understanding assisted by diagnostic procedures. Among non-destructive techniques, the Sonic Pulse Velocity Test (SPVT) qualifies the compactness of a masonry wall through elastic wave transmission. However, it does not directly estimate any mechanical parameters. This study presents findings from a database of 346 direct SPVTs carried out over thirteen years on both listed and ordinary buildings. Results were categorized based on masonry type according to the Italian building code, to derive information about construction quality and relate SPV with building features. Tests performed on 37 masonry panels strengthened by grout injections also confirmed the validity of SPVT in evaluating the effectiveness of the intervention. Furthermore, the Masonry Quality Index (MQI) method permitted to refine the masonry type definition through the judgment of the units’ arrangement. MQI and SPVT results were also combined by statistical analysis. These findings aim to increase comprehension of the different types of existing masonry capacity and contribute to engineering assessments for ensuring the structural safety of historical buildings.

Investigating worldwide strong motion databases to derive a collection of free-field records to select design-compatible waveforms for Switzerland

The process of choosing ground motions typically relies on assembling a collection of ground motions that match a desired spectrum. This selection process is guided by specific seismological criteria, including factors like earthquake magnitude, distance from the epicenter, site soil type, and the range of spectral periods that need to fit with the target spectrum. The selection algorithm and the available dataset of waveforms obviously play significant roles in this process. In many engineering and site response applications, it is essential that the input ground motion is representative for the shaking at the free surface of the Earth, and at times also a specific soil type may be required. However, real waveform databases often lack sufficient and/or consistent metadata related to the installation type and soil characterization of recording stations, as well as to the earthquake seismological parameters. This deficiency can lead to the selection of inappropriate waveforms, such as those recorded by stations situated within manmade structures (buildings, bridges, dams) or on a soil type different than the intended one. To address this issue, our approach for creating an appropriate waveform database applicable to Switzerland starts with the computation of seismic hazard disaggregation for return periods of 475 and 975 years. This computation helps identifying the magnitude-distance scenarios most relevant for the five seismic hazard zones defined in the Swiss building code. Once these magnitude-distance ranges are identified, we adhere to established standards regarding the quality control of three-component waveforms and their associated metadata. We assemble a database of waveforms by collating and homogenizing data from available global databases. In the interest of comprehensiveness, we also incorporate data obtained from 3D physics-based numerical simulations of strong-motion near the seismic source. Finally, we employ an algorithm that integrates the Eurocode 8 waveform selection criteria. This algorithm allows us to select and scale waveforms suitable for microzonation and structural analysis studies within each of Switzerland’s five seismic hazard zones. Selecting waveforms compatible with the target design spectra proves to be challenging due to the stringent criteria imposed by Eurocode 8. This challenge arises from the scarcity of recorded waveforms with verified metadata and precise site characterization in the desired magnitude-distance ranges.

Performance assessment of stairwell smoke prevention techniques in a model high-rise building

The complexities of construction and increased fuel loading in high-rise buildings implied engineers to shift towards performance-based design (PBD) instead of prescription design to ensure a higher level of fire safety. Since PBD is an iterative process, so engineering models and tools based on numerical techniques are generally used to evaluate the trial designs. In the present study, various methods of stairwell smoke prevention have been analysed and compared using Fire Dynamics Simulator (FDS) in a model high-rise building. Optimization is done by defining critical values of smoke layer height and maximum pressure differential as 2 m and 55 Pa, respectively. Results demonstrated that natural and cross ventilation in the stairwell are not fully effective for smoke prevention due to the enhanced stack effect observed in them. Further, the pressurization of stairwell at a minimum differential pressure of 25–30 Pa seems to be effective only when all windows in the stairwell are closed. Effectiveness of single and multiple injection pressurization techniques are also assessed. The single injection system fails to maintain the required pressure differential when multiple doors are opened and causes high-pressure differentials at the top stories. Open windows in the stairwell reduce the effectiveness of the pressurization method. Placing an exhaust duct near windows enhances the effectiveness of the PPV method, even at lower capacities of supply vents, and proves effective when stairwell windows are open by creating a higher stack effect in the exhaust duct. The current research involved a comparative analysis of various stairwell smoke prevention methods, as outlined in NFPA 92 and in accordance with the National Building Code of India. The findings may have broader applicability beyond the studied context.

The evolution of reaction to fire classification of materials: A case study of Canada

AbstractCombustible and noncombustible notions have evolved with time, along with the associated fire tests by which legislation classifies building materials. New Zealand, Japan, and Europe are just some of the many legislations that have followed this evolution, except for North American regulations, which remain attached to methods dating back to 1944. To better understand this stagnation in North American practices, this document first traces the evolution of Canadian regulations on fire classification of materials. Then, a parallel is drawn with the evolution of reaction to fire tests mandated in the National Building Code of Canada. Finally, this paper will review the current fire classification of materials concerning the combustibility concept based on the Steiner tunnel test and the flame spread rating criteria. The analysis reveals that the relevance of the test and its results are questionable, and the reciprocity between test measurement and its classification does not always coincide. Despite the revisions made through time, the classification of materials based on their fire properties remains distinctly binary.

Digital Evolution in AEC industry: Bridging BIM, Building Codes, and Future Technologies

Abstract In recent decades, the Architecture, Engineering, and Construction (AEC) industry has witnessed profound shifts driven by digital technologies. Central to this transformation is Building Information Modelling (BIM), which has offered a holistic approach to design, analysis, and documentation, yielding benefits in visualization, collaboration, simulation, and life-cycle management. However, the industry’s intricate regulatory landscape, primarily rooted in traditional text-heavy building codes, has lagged in digital adaptability. This paper explores the imperative to transition building codes and regulations into machine-friendly formats, capitalizing on structured databases, semantic annotations, and (Application Programming Interface) API-driven access. Such a transformation facilitates streamlined (Artificial Intelligence) AI-based compliance checks and augments the capabilities of BIM systems. Furthermore, the research delves into the convergence of BIM with other burgeoning technologies. Extended Reality (XR) promise enriched visualization and on-site integration. AI introduces automated analytics, optimization, and predictive facilities management. The integration of Internet of Things (IoT) proposes a real-time feedback loop into BIM, evolving towards dynamic Digital Twins. The discussion also touches upon the potential of XR technology use for enhanced workforce performance and quality control on the site. In conclusion, the AEC industry stands on the edge of a digital evolution, demanding integrated approaches to fully harness the potential of these technologies, ensuring not only efficient construction practices but also enhancing building safety and sustainability.

Development of Seismic microzonation for Rancaekek Sub-District using microtremor method

Abstract Rancaekek sub-district located in the Bandung Regency is geologically characterized by soft and loose sediment layers such as clays, silts, and sands associated with the old Bandung Lake. Due to the existence of the Sesar Lembang Fault, the Rancaekek area is also vulnerable to seismic disasters. To provide knowledge on seismic vulnerability, therefore, a seismic microzonation study was conducted at 25 locations in the Rancaekek area using the microtremor method. Based on the available microtremor measurement data, the seismic vulnerability of the Rancaekek sub-district varies from one area to another. Amongst other areas Northern part of Bojongloa, Northern part of Rancaekek Wetan and Northern part of Jelegong areas are the most vulnerable to seismic damage because these areas have low dominant frequencies with medium amplification zones, and low Vs30 values ranging from 90 to 127 m/s. Thus, any building and infrastructure development in these areas should follow the national building code to reduce damage due to earthquake shaking.

Newly developed site-specific response spectrum for site in Abbottabad city, Pakistan and its comparison with building code of Pakistan, 2021

Use of site-specific response spectrum has become an integral part of seismic hazard analysis to incorporate the effects of soil beneath the structure. Current study has been performed as a result of lesson learned from recent devasting Turkey earthquake of 6th February 2023, where design ground motions were greatly exceeded. This study presents development of site-specific response spectrum and its comparison with recently published building code of Pakistan, 2021. The results of this study indicate that mobilized shear strength of input motions increased along depth due to development of different shear strain in different soil layers which affected the shear modulus showing its resistance to deformation by exerted shear stress. Input bedrock motions with PGA of 0.31g amplified at the surface up to 0.36g as result of response from the soil profile used. After comparison with design spectrum of building code 2021, it is further validated that the development of site-specific response is underpinning when using design spectrum of BCP-2021 developed for return period of 475 years under currently used soil/site conditions.

Assessment of Subsidies for Construction Businesses in Nigeria: Evolution from an Oil-Based Economy to an Infrastructural-Based Economy

Subsidies are financial or non-financial aids or support given to an economic sector, individual or organization by their government to promote the economy and achieve specific policy objectives. This study assessed the use of subsidies for construction businesses in Nigeria with a view to revolutionize the country from oil-based economy to infrastructural-based economy. A structured questionnaire was administered to four hundred and four (404) construction business stakeholders, and three hundred and four (304) representing 75.25% were retrieved from the respondents. Findings revealed that buying and selling of construction materials with Mean Score (MS) of 3.97 is the most successful construction businesses in Nigeria. The major factors considered in rating construction business performance are profitability to the investor (MS=3.70), resource management and control (MS=3.68), and cost performance (MS=3.63). The study concluded that the establishment of construction related institutions (MS=3.97), enforcement of health, safety, and hazards prevention policies (MS=3.91), exchange rate moderation for construction business (MS=3.86), and implementation of the National Building Code (NBC) (MS=3.85) will grow the infrastructural economy. The study recommended subsidies for construction businesses in Nigeria to boost the infrastructural sectors and the economy.

The Recent 2023 Earthquake in Nepal: A Global Health Perspective.

As a seismic hotspot, Nepal has endured many catastrophic earthquakes, including the 2023 Jajarkot quake. These quakes worsen the existing fragilities, resulting in difficulties in accessing healthcare, outbreaks of infectious diseases, mental health problems, and nutritional shortfalls. The article examines the complex web of health consequences, such as infectious and non-infectious diseases and malnutrition, highlighting the need for a global health lens in tackling these issues. It also reveals the long-term health effects, such as mental health disorders and increased disease susceptibility, that emerge after the quake and the importance of enhancing coordination and communication, enforcing building codes, and assisting affected communities in response to the seismic hazards. The article identifies mitigation strategies, community involvement, and international cooperation as key elements in building resilience against future quakes. It discusses the role of climate change in seismic risks and the need for research, innovation, and adaptability in global health interventions, suggesting measures such as strengthening primary healthcare, preventing avoidable health problems through education, and improving supply chains. The article calls for a holistic approach to building resilient health systems, emphasizing community engagement, prevention, and preparedness to protect the health of vulnerable groups in seismic regions.

Barriers to long-term disaster recovery in rural Appalachia: A retrospective analysis of the 2016 West Virginia flood

The research presented in this paper explores the barriers to long-term disaster recovery in understudied rural communities in the eastern United States, along the Appalachian Mountains. This region, referred to as Appalachia, faces many of the same barriers to long-term disaster recovery as urban communities but also faces unique circumstances due to depressed socioeconomics, reduced access to public services, and the nominal capabilities of small, rural town governments. Devasting floods occurred throughout the eastern and central regions of Appalachia in 2016. Interviews were recently conducted with local, state, and federal government officials, nonprofit groups, and industry professionals about the long-term recovery efforts from this event. The findings highlight a multifaceted set of barriers. A total of twenty-two barriers are described, including limited economic resources, lack of flood insurance, slow allocation of funding, skilled labor shortages, unclear roles and responsibilities among stakeholders, a lack of long-term planning, regulatory delays, complex reimbursement processes, uncertain design standards, an attachment to flood-prone regions, and a lack of knowledge of building codes. Many of these barriers compound each other. Future research is needed to develop solutions that address these barriers for small, rural communities still straining to recover from a disaster that occurred years ago.

Seismic Reliability Maps of Code-Compliant Italian Reinforced-Concrete Bare and Infilled Frame Buildings

The present study illustrates the main results of an extensive campaign of numerical simulations aimed at quantifying the seismic reliability of reinforced concrete (RC) bare and masonry-infilled frames compliant with the current Italian Building Code. For this purpose, a set of different residential-use archetype structures are considered, and a prototype seismic design-assessment tool is created to quantify their performance with respect to the relevant limit states, deriving fragility curves via the execution of several non-linear time-history analyses (NLTHAs). The fragilities are subsequently combined with the hazard curves derived for each of the over 8000 Italian municipalities based on the national seismic hazard model currently in force to obtain the respective seismic mean failure rates across Italy. The seismic reliability maps obtained for the investigated code-compliant designs highlight how the current Italian Building Code fails to provide uniform seismic safety across Italy, showing—on the contrary—a strong hazard-dependency. The results are finally used to calibrate regression laws able to correlate the seismic mean failure rates with an intensity measure representative of the seismic hazard.

Measurement of air permeance in mass timber elements assembled through the dovetail technique

Adhesives and metal fasteners are important components in engineered wood products (EWPs), but the petroleum-based nature of adhesives raises environmental concerns and metal fasteners lead to challenges with end-of-life disposal and reusability. However, there is a promising solution in the form of ‘mass timber elements assembled through the dovetail technique (MTADT)’, also called ‘dovetailed massive wood board elements’, which is entirely composed of wood and devoid of adhesive or metal connections. However, existing literature on MTADT has focused on insufficient structural analysis and model testing of connection details rather than assessing the performance of a structural component. In this study, air permeance measurement in MTADT was conducted in accordance with the Finnish building code as part of the DoMWoB project (Dovetailed Massive Wood Board Elements for Multi-Story Buildings). The research aimed to explore the impact of storage conditions and moisture content on the air permeance values of three massive wood elements with varying dimensions. The smallest element had dimensions of 1160 mm × 1160 mm x 200 mm, while the other two were approximately 1300 mm × 1300 mm x 200 mm in size. The results from the air permeance tests indicated significant variability among the three test pieces, with q50 values of 1.4 m³/(m2h) for sample O, 2.9 m³/(m2h) for sample K, and 9.9 m³/(m2h) for sample Y. This data suggested that test piece Y demonstrates substantially higher air permeability compared to the other samples because it was the driest of these test elements.

Hygrothermal Performance of Roofs with High Initial Construction Moisture Subjected to Hot Climate

Moisture accumulation in the building components/assemblies that form building envelopes can lead to material deterioration and moisture related issues such as mould growth. As a part of the building envelope, this study focusses on assessing the moisture performance and energy performance (i.e., hygrothermal performance) of roofing systems. As roofs can be built with high initial construction moisture, numerical simulations were conducted with and without high initial construction moisture in order to investigate: (a) the hygrothermal performance of cool and black roofs having material layer with high initial construction moisture content, (b) the time needed so that the moisture content reaches acceptable level as per the building code requirements, (c) whether moisture accumulation and mould growth occur in the roofs, and (d) the energy savings as a result of installing white/cool roof instead of black roof. An advanced numerical model is used to conduct the numerical simulations for black and cool roofs when they are subjected to hot climate. This model solves simultaneously the Heat, Air and Moisture (HAM) transport equations in all layers of the building assemblies. The model was extensively validated by comparing its predictions with the experimental data of different building components at various operating conditions. For the roofing systems investigated in this paper, the results showed that mould growth occurred in the black and cool roofs only for the case with high initial construction moisture. The mould has totally disappeared after 378.8 day for the black roof and 479.3 day for the cool roof. The temperatures of the cool roof were much lower than those for the black roof. The total yearly energy load with the black roof was 77% greater than that with the cool roof.