Learning Environments Research

Introduction The seismogenic liquefaction of the soil poses a great hazard to society and the environment. Therefore, it is actively studied in many countries. In Russian engineering and seismological practice, this area is not sufficiently developed. The deterministic approach still prevails in Russian research on this topic. More modern probabilistic estimates are very rare. Methods This paper describes examples of both deterministic and probabilistic assessments of the seismogenic liquefaction hazard performed in certain areas of the Russian territory with different seismogeological conditions. Deterministic estimates were made using the Iwasaki-Seed-Finn methods and their modifications. Probability distribution functions of a random variable, the “seismic potential of liquefaction” (SPL), were developed for probabilistic estimates. These functions are regional in nature and take into account two types of uncertainties. The first is the uncertainty in achieving “critical” values by the SPL value in the event of potentially dangerous earthquake sources for a given location. The second is the uncertainty in the very occurrence of these sources in a given place for a given period of time. The “critical” SPL values are determined by the strength properties of the site soils. All estimates are based on multivariate calculations using various models of strong ground motions and seismicity. In all cases, the probability of liquefaction of water-saturated sandy and sandy-loam deposits was estimated which were found near the seabed and at depths of up to 80 m in the waters of Pogibi cape (the coast of Sakhalin island), in the districts of Sochi and Novorossiysk, as well as in land conditions (Stavropol, Krasnodar). Results The results of the research made it possible to correctly (at the quantitative level) take into account this component of the seismic hazard of the studied territories. Conclusion The variants of practical use of the obtained data are offered. An assessment of the possibilities and limitations of the developed methodology is made, and ways to improve it are outlined.

Aim The aim of the study is to develop a scheduling and cost estimation model for repetitive construction units by applying the learning curve theory and to contribute to advancements in construction project management practices, promoting efficiency and competitiveness within the industry. Background Construction projects, particularly those with repetitive units like housing developments, face ongoing challenges in accurate scheduling and cost estimation. Traditional estimation methods often overlook the impact of learning effects, which can improve productivity and reduce costs as crews gain experience. Learning curve theory, widely applied in manufacturing, offers a framework to model these gains in construction settings. Integrating learning curves into project planning has the potential to enhance accuracy in forecasting timelines and budgets, ultimately improving project efficiency and resource management. Objective The objective of this study is to develop and apply a learning curve model to enhance scheduling and cost estimation in repetitive construction projects, particularly in a multi-unit housing project. Methods By incorporating historical data and analyzing critical factors that impact project duration and cost, a more reliable forecasting model is developed. The learning curves are created using a three-point approach, supported by artificial neural networks (ANN) and the relative importance index (RII), to systematically assess cost divisions and influential project factors. Results The results indicate that the learning curve model can achieve time savings of 27% and labor cost savings of 36% compared to traditional estimation methods that do not consider the effect of the learning curve in construction projects. Conclusion This research demonstrates that learning curve models, combined with advanced data analysis techniques, provide a robust framework for optimizing project schedules and budgets, ultimately leading to more efficient resource utilization and cost-effective project outcomes. In other words, the study presented in this paper is significant as it can lead to improved project outcomes, cost savings, better resource management, and overall advancement in the construction industry's practices and competitiveness. This approach allows for accurate scheduling and cost forecasting based on data-driven insights.

Introduction The adoption of biogenic building materials is an important step towards decarbonizing the construction industry. However, a number of constraints limit their wider adoption in the industry. Objective To determine and analyse the financial constraints (FC) to the adoption of biogenic building materials; examine how they relate to one another; and provide strategy for overcoming the constraints to promote wider utilization of the materials in building construction. Methods The data for the study was obtained using methodical review of related literature and expert-based survey while the results were analysed using the decision-making trial and evaluation laboratory (DEMATEL) technique. Results The findings indicate that the most critical constraints with the strongest level of cause on other FC are high initial costs of materials (FC3), high design & production cost of the materials (FC4), lack of standardization & certification (FC7), difficulty in upscaling production (FC1), and limited access to capital and financing options (FC8). Conclusion This study contributes to advancing knowledge in sustainable construction practices by determining and understanding the specific financial constraints that impede the widespread adoption of biogenic building materials within the construction industry. By addressing these constraints, the study promotes sustainable practices within the construction sector, contributing to environmental conservation and resource efficiency.

Aim The aim of this study is to introduce the critical impediments to historic building retrofitting that can be specifically tailored and applied to managing historic building protection while also achieving net zero emissions and improving the sustainability of the buildings. Background Despite the various calls advocating for the sustainable retrofitting of historic buildings to reduce carbon emissions and enhance energy efficiency, the extent of possible alterations that can be made to historic buildings is restricted because of their historical, architectural, and cultural significance, which is one of the many critical impediments of retrofitting historic buildings. While there are existing studies that focus on identifying some of the impediments to retrofitting historic buildings, most of these studies did not systematically examine the interrelationships among these impediments. An effective retrofit of historic structures can be greatly influenced by having a proper understanding of how various impediments interrelate with one another. Objective The objective of this study is to identify, analyze, and prioritize the critical impediments to historic building retrofitting to improve their sustainability and attain net zero emissions. Methods The data for the study was gathered using a systematic review of related literature and expert-based survey, while the results were analyzed using the interpretive structural modelling (ISM) technique. Results Based on the study findings, the top-ranking impediments that have the greatest impact on other impediments and are crucial in projects for retrofitting historic buildings are “high costs of retrofit projects,” “poor stakeholders' engagement and coordinated efforts,” and “disparity between the buildings' energy efficiency levels & historical significance.” Conclusion The study reported in this paper fills an existing gap in the literature, which also offers useful insights into a crucial area of managing historic building conservation and enhancing energy performance. The major managerial implication of this research is the need for strategic planning and decision-making. Policymakers and heritage conservation practitioners should carefully consider the study findings to create a comprehensive strategy that successfully addresses the critical impediments that have been identified. Thus, future research can investigate how historical authenticity and values can be preserved while enhancing energy efficiency and cutting emissions through the integration of sustainable retrofitting approaches with preservation initiatives.

Introduction The main materials utilized in the production of reinforced concrete are aggregates, cement, and steel. The production of steel and cement contributes to the generation of carbon dioxide emissions, which is a main cause of global warming. Methods To further enhance sustainability in the construction industry, this study focuses on utilizing alternative sustainable materials in bamboo-reinforced concrete containing cassava peel ash (BRC-CPA) by fully replacing steel with bamboo strips and partially replacing cement with cassava peel ash. The experimental phase includes material characterization for the cassava peel ash (CPA) and bamboo reinforcements. Eighty-nine samples of BRC-CPA beams with dimensions 100×150×500 mm were produced, and bamboo strips of three different sizes, 12, 14, and 16 mm, were prepared and used as reinforcement in the BRC-CPA beams to evaluate their flexural strength and flexural strain. In addition, 12 samples of 150 mm cassava peel ash-blended concrete (CPAC) cubes without bamboo strips were produced. The cassava peel ash was used to partially replace cement at three levels, 0, 10, and 20%, to evaluate their influence on the compressive strength and water absorption of concrete cube samples. Results The addition of CPA slightly reduced the compressive strength of CPAC cubes, with values of 23.4 N/mm², 22.2 N/mm², and 21.4 N/mm² observed for 0%, 10%, and 20% CPA replacement levels, respectively. However, incorporating CPA had a positive effect by reducing water absorption and narrowing the flexural crack width in BRC-CPA beams. The flexural strength of BRC-CPA beams increased as the concrete aged, but decreased as the bamboo reinforcement size increased. Notably, at 20% CPA replacement, the flexural strength was less influenced by the bamboo strip size compared to beams with 0% CPA. Conclusion Based on experimental results obtained for compressive strength, flexural strength, and flexural crack width, cassava peel ash at 10% replacement and bamboo strips of size 14 mm were recommended for use in BRC-CPA for concrete structural elements such as beams, columns, and slabs.

Background The construction industry in Saudi Arabia faces numerous challenges that hinder its progress due to frequent and prolonged project delays. Objective The specific objectives of this study are (1) (1) To analyze the factors contributing to construction project delays in Saudi Arabia, (2) To identify the risk of factors contributing to construction project delays, and (3) To propose strategies to mitigate construction project delays in Saudi Arabia. Methods The study reviewed 16 articles to identify and suggest solutions for construction project delays in Saudi Arabia. Results There are 140 factors of delay found and seven pose unacceptable risks including delays due to material delivery, delays in approval of submittals, design drawings, shop drawings, and sample materials (making decisions), delays related to subcontractors work, inflation and escalation of material prices (changes in price), lack of coordination with contractors, shortage of construction materials (non-availability of material), and equipment shortages. The risk assessment can be conducted using the Bowtie diagram, scenario analysis, MRM, and MCS separately or collectively to get a new and improved model. Conclusion This review will contribute to the development of strategies to enhance the performance of ongoing and future construction projects in the region. Additionally, decision-makers can utilize the outcomes to strategically allocate resources and improve construction project success.

Introduction The ambiguity regarding the geological interpretation has the potential to be significantly decreased with the use of remote sensing, geophysical data, and the history of geology. Aims The objective of this work is to delineate geological lineaments and faults using EIGEN-6C4 satellite gravity and ALOS PALSAR radar data in the north Ghadames basin, of northwest Libya. Methods The satellite gravity dataset of the study region was used to perform a complete Bouguer anomaly map of the study area to start the gravity interpretation. Then different filters were performed on the gravity dataset, such as the total horizontal gradient (THG), CET grid analysis, 3-dimensional Euler solution (ED), and a tilt derivative (TDR) using the commercial Oasis Montaj programme. The techniques of edge identification (THG, TDR, and also CET grid analysis) are utilised for locating and identifying the boundaries or edges of geological structures that contribute to gravity anomalies. The 3-dimensional Euler solution, in conjunction with the TDR method, is employed to precisely figure out the positions and estimated depths associated with subsurface sources. Radiometric calibration, speckle filtering, and geometric correction were applied to preprocess the ALOS PALSAR L 1.1 image via the Sentinel Application Platform (SNAP) software. For automatic extraction, the PCI Geomatica software's LINE module was applied. Results The gravity data results indicate that the main trends of the identified geological lineaments are oriented in the North-South, East-West, Northwest-Southeast, and North-Northwest to South-Southeast directions. Furthermore, the depths of the sources observed underneath the study region differ from 250 m to 2750 m. The orientation of extracted lineaments from the ALOS PALSAR L1.1 images, specifically the horizontal-horizontal as well as horizontal-vertical polarisation images, predominantly have orientations in the north-south, north-northeast to south-southwest, east-west, north-northwest to south-southeast, and northeast-southwest directions within the study area. Conclusion All these findings of lineaments are associated with the tectonic features of the area. Consequently, identifying these lineaments/faults is important to reduce the ambiguity of geological interpretation and provide more information on the dominant trends for future exploration activities in the study region.

Introduction An in-depth understanding of the ground subsurface is crucial for foundation design and excavation works and for avoiding potential hazards during land development. In this regard, the ground rippability and weathering grades are some of the ground information needed. While geotechnical works are preferred, their limited horizontal coverage and high cost are often constraints that limit their use. Aims To counter this, a geophysical survey is employed for its wider area coverage and cost-efficiency. Therefore, this study used the seismic refraction method to assess the rippability and weathering grades in a sedimentary rock geological setting (interbedded sandstone, siltstone, and shale) as a preliminary ground assessment. Methods A seismic refraction survey was carried out using Aktiebolaget Elektrisk Malmletning (ABEM) Terraloc Pro 2, where the survey line was 115m long. Rippability was obtained by correlating seismic values with the Caterpillar D10R rippability table. Meanwhile, the weathering grades of the ground were determined by correlating the study area with another study area of a similar geological setting. Results Within the 39m penetration depth, three layers can be classified from the ground’s P-wave velocity values and D10R Caterpillar rippability chart, which include rippable, marginal, and non-rippable layers. A break in the continuous ground layers could be seen, causing lower velocity values to be sandwiched between high velocities, which signified the presence of fracture. The weathering grades were also successfully classified from the seismic velocity values. Conclusion Using seismic refraction method, this study successfully employed seismic velocity values in determining the rippability and weathering grades of interbedded sedimentary rock without borehole record.

Recent years have witnessed a significant growth in the research and development of additive manufacturing methods involving concrete and cementitious materials, with technologies like three-dimensional (3D) printing becoming more widely used in the construction industry. Construction has the possibility to be revolutionized, not only in the context of cost savings but also in the context of increased sustainability and functionality. 3D printing of concrete is a cutting-edge technology that has the potential to speed up construction, reduce labor costs, give architects more creative freedom, improve precision, obviate requirements for formwork, and result in less construction wastes. In addition, 3D printing can be a long-term solution for both economy and environment. Even though 3D printing in concrete has made tremendous strides recently, developing an effective 3D-printable material that decreases material usage and enhances performance is critical for carbon dioxide reduction. Robust geopolymer formulations for 3D printing concrete technology in current construction applications have emerged as the subject of much research among scientists to find novel ways to circumvent this constraint. This study intends to highlight the current state of the art in developing 3D-Printed Geopolymer Concrete (3DPGC) with a comprehensive review related to the material composition, mix design, and mixing regimes on rheology of 3DPGC. The rheology of 3DPGC in terms of printability and buildability is discussed. The mixing regimes employed for the preparation of one-part and two-part 3DPGC are tabulated and commented on. Lastly, the research gaps are identified and summarized, and several research directions are also provided for future investigations to expedite the ubiquitous use of 3DPGC in versatile construction applications.

Introduction Slope stability and soil erosion are major concerns in geotechnical engineering and land management. This research investigates the relationship between soil type and root systems in stabilizing slopes. Methods The main aim is to measure the effectiveness of Eugenia Oleina as a bioengineering technique for slope protection. Laboratory tests were conducted to measure soil shear strength, root properties, and the factor of safety (FOS) of tropical slopes before and after plant root implementation. Results Results revealed significant differences in cohesion and angle of friction values between unrooted and rooted soil. Apart from that, it was observed that as the root diameter increased, the tensile strength decreased when the applied force increased. The FOS of unrooted soil was higher than rooted soil, indicating greater stability without any vegetation. Furthermore, this study also evaluated the use of bio-anchorage to prevent soil erosion, considering factors such as soil composition, vegetation, and external loads. Finite element analysis was carried out using Plaxis 3D simulations to assess the effectiveness of Eugenia Oleina in controlling slope erosion. Conclusion This study contributes valuable insights in choosing suitable plant species for erosion control in tropical soil and guides soil bioengineering practices for slope stability in various soil conditions.

Introduction Landslides frequently occur along roads crossing mountainous terrain during the rainy season, posing a significant risk of severe disruption to land transportation routes. Efficient and accurate resolutions are essential in managing landslides to facilitate immediate transportation recovery, such as gabion walls and pile installation. Aim This article aimed to evaluate the effect of installing gabions and piles for safety measures on the stability of slope landslides. The analysis of slope stability was performed utilizing the Plaxis 2D software. For reinforced slopes, the Safety Factor (SF) value utilized as a benchmark for evaluating slope stability was SF ≥ 1.5. Methods An assessment of the stability of the slope was conducted under three conditions: its original state, after reinforcement with gabions, and after the integration of gabions with mini piles. The dimensions of the gabion setting, as determined by the L-W-H notation (length-width- height), were 2 m x 1m x 0.5 m and 1 m x 2 m x 0.5 m. The pile was designed to be 2.5 m long at the gabion's end. The analysis was conducted at 45°, 60°, 70°, and 90° slopes. Results Based on the results of slope stability calculations, an SF = 1.11 was determined under no reinforcement conditions. By applying reinforced gabion walls measuring 2 m in width combined with mini piles at a 45° slope, the best SF was achieved, which was 2.58. Conclusion Given the comparable topographical circumstances, it is expected that the outcomes of this analysis on slope stability will be applicable in mitigating the occurrence of landslides.

Introduction The current study's goal is to apply an integrated approach of retrofitting a typical building in Cyprus that was designed and constructed for the refugee settlements in the period 1975-1985. The existing building is retrofitted to a nearly zero-energy building. Methods This typical type of building examined represents approximately 15,347 houses and stands for 3.57% of households in Cyprus. This percentage is considered significant with regards to energy consumption, as this type of structure has an estimated energy consumption of 1000 kWh/m2/y and CO2 emissions of 293.74kg CO2/m2/y. This corresponds to 0.293 Mt CO2/y, which stands for 4.18% of total CO2 emissions in Cyprus for 2011, based on the latest IEA (International Energy Agency) data. An integrated approach is followed for the retrofitting of the existing building, which involves both energy and structural upgrades, taking into account the earthquake resistance upgrade. Since Cyprus is in a highly seismic region, an important factor in this approach is the ability of the structure to survive a strong earthquake during its remaining lifetime, according to the design criteria. The study presents and discusses three possible coalitions with multiple scenarios of approaching the upgrade of the existing building. In each coalition, various criteria and implementation actions are considered based on the energy consumption, the CO2 footprint, and the seismic resistance. Results The study also investigates whether the extension of life expectancy of the existing structure through earthquake resistance upgrade will have a positive or negative effect on the CO2 life cycle footprint and cost of the building. Results show that for the examined typical building, simultaneous energy and earthquake resistance upgrade is more efficient in terms of cost and environmental impact. The building with the smallest construction age had the smallest Decision-Making Index (DMI) from the A, B and C coalitions. Conclusion It is important that for an existing building, the option to remain in its original state (coalition A) without any upgrading intervention is not the most favorable option. Therefore, the need to evaluate the existing building stock and plan the upgrade of the buildings in question is of utmost importance.

Introduction The escalating demand for concrete, driven by global infrastructure development, poses significant challenges to environmental sustainability due to the depletion of natural resources and the accumulation of waste materials. This paper explores the potential of utilizing waste materials, particularly palm oil clinker (POC) and spent garnets, as sustainable alternatives in concrete production. The depletion of natural aggregates, such as river sand, coupled with the environmental hazards associated with waste disposal, underscores the urgent need for eco-friendly solutions in construction materials. POC, derived from palm oil production waste, and spent garnets from abrasive industries offer promising avenues for reducing environmental impact and enhancing sustainability in concrete production. By addressing the dual challenges of resource depletion and waste management, this research aims to contribute to developing greener construction practices and mitigating environmental degradation. Aims This study aims to investigate the effects of incorporating spent garnet as a partial fine aggregate replacement on the fire resistance of POC LWAC. By examining the interplay between spent garnet inclusion and fire resistance, the research contributes to developing more sustainable concrete formulations and aids in industrial waste management practices, addressing critical societal and environmental challenges. Methods This study investigates the effects of elevated temperatures on the compressive strength and durability of POC LWAC specimens. Concrete specimens were demoulded after 24 hours of curing and submerged in water for 28 days. Compressive strength and water absorption tests were conducted at the end of the curing period. Subsequently, specimens were subjected to temperatures of 300 °C, 500 °C, and 700 °C for 1 hour in a furnace. After cooling naturally for 24 hours, visual inspection, mass reduction analysis, and evaluation of residual compressive strength were performed. Results Results indicate that 20% garnet replacement yields the highest compressive strength due to pore filling and denser structure. Higher garnet levels lead to reduced strength and increased water absorption. Visual assessment post-heating shows surface alterations, with 20% garnet exhibiting the lowest mass loss and strength reduction at elevated temperatures. Conclusion Notably, specimens containing 20% spent garnet in POC LWAC performed better in a fire than others, enhancing their fire-resistant properties. In summary, this research introduces a hopeful approach to improve the sustainability of concrete and mitigate the environmental repercussions of industrial waste.

Introduction The distribution of suction, which has implications for seepage and shear strength, plays a crucial role in determining the stability of unsaturated soil. The Air Entry Value (AEV) and Residual Water Contents (RWC) change over time to create the Soil-Water Characteristic Curve (SWCC), which is very important for figuring out how the suction is distributed. During a flood occurrence, the subgrade becomes inundated with water, leading to adverse effects on the AEV and RWC of the subgrade. Consequently, the performance of the subgrade is diminished. This study focuses on the use of Marble Dust Waste (MDW) as an addition to the subgrade to improve the strength of the subgrade. Aims This study aims to investigate the variations in air AEV in relation to the optimal MDW in unsaturated soil found in Malaysia. Methods The study uses control samples and soil that has been mixed with different amounts of MDW: 5%, 10%, 15%, 20%, and 25%. The SWCC is generated using the pressure plate extractor device. Results The results indicate a significant increase in the AEV for the mixed soil sample when compared to the control sample. While the soil-MDW mixture containing 5% of this material has an AEV value of 23 kPa, the control sample's value is 10 kPa. Conclusion The findings of the study suggest that the utilization of MDW yields a beneficial influence on the AEV, hence potentially improving the performance of the subgrade. The researchers aim to evaluate the potentially dangerous waste and convert it into a substance that is appropriate for engineering applications. This study provides empirical evidence that aligns with the objectives outlined in Chapter 8 of the 12th Malaysia Plan for the period 2021–2025. The topic under discussion pertains to environmental sustainability, specifically focusing on enhancing the ability to withstand the adverse effects of climate change and disasters, as well as the Green Technology Master Plan Malaysia 2017–2030, with a specific emphasis on Chapter 6, which addresses the issue of waste management.