Improve Construction Quality Research Articles

Bonding performance and construction parameters of low-rebound shotcrete

Abstract Shotcrete has the advantages of short setting time, high early strength, simple process and flexible operation methods. It is mainly used as temporary support in domestic highway tunnels. This study investigates the development of low-rebound shotcrete for tunnel construction by adding silica fume and fly ash into the mixture. Sandstone and limestone were employed to simulate the surrounding rock. The workability and mechanical properties of the shotcrete were evaluated based on slump tests, rebound rates, compressive strength measurements, and bonding strength tests between the surrounding rock and the shotcrete. Furthermore, the research investigated construction techniques, with an emphasis on spraying distance, shrinkage angle, and wind pressure, and optimized these parameters for practical engineering uses. The outcomes demonstrate that the addition of silica fume enhances the mechanical properties of the shotcrete and reduces rebound. It was discovered that optimal spraying distance was between 1.2 m and 1.5 m, with the optimal wind pressure at 0.5 m, and the ideal shrinkage angle at 6°. Research on low rebound shotcrete is of great significance for improving construction quality, construction efficiency and engineering structural performance, and also meets the requirements of sustainable development.

城市燃气工程项目施工质量控制及优化策略研究

This paper explores the quality control and optimization strategies for gas engineering projects, aiming to analyze and summarize the key technologies and management methods that enhance the quality and efficiency of gas project construction. First, the characteristics of gas engineering construction and its significance in energy infrastructure development are introduced. Then, the current quality issues in gas engineering construction are analyzed, followed by a discussion on how to improve construction quality through key technologies such as thorough preparatory work, material selection and inspection, and adherence to construction processes and operational standards. Further, the importance of optimizing project management and coordination mechanisms, improving resource allocation and utilization efficiency, and implementing green construction and environmental protection measures in enhancing overall project quality and sustainable development capabilities is discussed. Finally, the paper emphasizes that through a comprehensive strategy of technological innovation and integrated management, it is possible to effectively raise the quality standards of gas engineering projects, thereby promoting industry growth and contributing to the sustainable development of society and the economy.

Seismic Performance of Corroded ECC-GFRP Spiral-Confined Reinforced-Concrete Column.

Preventing corrosion in the steel reinforcement of concrete structures is crucial for maintaining structural integrity and load-bearing capacity as it directly impacts the safety and lifespan of concrete structures. By preventing rebar corrosion, the durability and seismic performance of the structures can be significantly enhanced. This study investigates the hysteresis behavior of both corroded and non-corroded engineered cementitious composite (ECC)-glass-fiber-reinforced polymer (GFRP) spiral-confined reinforced-concrete (RC) columns. Employing experimental methods and finite element analysis, this research explores key seismic parameters such as crack patterns, failure modes, hysteretic responses, load-bearing capacities, ductility, stiffness degradation, and energy dissipation. The results demonstrate that ECC-GFRP spiral-confined RC columns, compared to traditional RC columns, show reduced corrosion rates, smaller crack widths, and fewer corrosion products, indicating superior crack control and corrosion resistance. Hysteresis tests revealed that ECC-GFRP columns, at a 20% target corrosion rate, exhibit an enhanced load-bearing capacity, ductility, and energy dissipation, suggesting improved durability and seismic resilience. Parametric and sensitivity analyses confirm the finite element model's accuracy and highlight the significant influence of concrete compressive strength on load-bearing capacity. The findings suggest that ECC-GFRP spiral-confined RC columns offer promising applications in coastal and seismic-prone regions, enhancing corrosion resistance and mechanical properties, thus potentially reducing formwork costs and improving construction quality and efficiency.

Boosting large‐scale construction project risk management: Application of the impact of building information modeling, knowledge management, and sustainable practices for optimal productivity

AbstractThis study investigates the relationship between Building Information Modeling (BIM) and knowledge management in large‐scale construction projects, emphasizing risk management, and increasing productivity. This study aims to identify the most important and impactful aspects of modern management techniques in the large‐scale construction sector to improve construction quality; focusing on cost reduction, energy conservation, and pollution reduction during construction. Employing a validated questionnaire from experts and the Analytical Hierarchy Process (AHP), the research prioritizes key factors, elucidating the pivotal role of BIM in understanding project geometry, efficient documentation, design flexibility, and reduced project delays. Ascertained through data analysis employing the pairwise comparisons method of the AHP analysis method, the compatibility of all comparisons and matrices arising from the decision‐making process of experts was below 0.1. The results establish BIM's technical capabilities, economic considerations, and pollution reduction as paramount, contributing significantly to improve large‐scale construction project risk management. The prioritization of the main criteria reveals their significance in the following order: BIM technical capabilities (0.281), BIM economic capabilities (0.231), pollution reduction (0.228), knowledge management capabilities (0.096), BIM time capabilities (0.090), and human resources management capabilities (0.074). BIM can improve risk management for large‐scale construction projects by: using the BIM model to understand the geometry and features of large‐scale construction projects; digitizing and organizing contract documents, project data, plans, work instructions, roles and responsibilities, cost, time, and energy analysis, and other project‐related documents for efficient project management; decreased duplication and project delays; reducing the need for on‐site personnel during implementation and CO2 emissions reduction. According to the results of the BIM model utilization to better understand the geometry and characteristics of large‐scale construction projects, the item was identified as the most significant and influential among the main components.

Discussion on Construction Technology of Subway Tunnel Expansion under Bridge Foundation

As the urban populations grow, the number and size of subway construction projects are increasing while also meeting higher construction standards. So, subway construction projects must have a better understanding of construction technology. This article focuses on the construction technology of the subway tunnel expansion under the bridge foundation. By analyzing the engineering characteristics of the bridge foundation and using a project as an example, this article provides a detailed discussion of the construction process of tunnel expansion under a bridge foundation. This article aims to serve as a reference for subway tunnel construction in China to ensure the key points of construction technology are understood, thus improving construction quality and laying a solid technical foundation for the sustainable development of urban rail engineering.

Research and evaluate the potential of rice husk ash and rice straw ash for soil improvement in Vietnam

Rice husk ash and rice straw ash are common agricultural wastes in developing countries. Currently, utilizing these wastes in the construction sector such as soil improvement and cement concrete production is a trend in many areas around the world. In Vietnam, with a rice production of more than 40 million tons/year, millions of tons of rice husk ash and straw ash can be generated. This is an abundant and a cheap material source. This article will research and evaluate the potential of rice husk ash and straw ash for soft soil improvement in Vietnam. Research results show that straw ash and rice husk ash are materials having high pozzolan activity. Various studies in the world and some studies in Vietnam showed that rice husk ash and straw ash not only improve some physical and mechanical properties of soil but can also partially replace the amount of binder. Vietnam has different types of soft soil and construction activities are increasing, so the demand for improving soft soil is also increasing. In which, improving soil with cement binder is one of the most popular methods. Therefore, rice husk ash and rice straw ash have great potential to combine with cement in improving soft soil in Vietnam. Utilizing these wastes not only helps reduce the negative impact their causes on the environment but also helps improve construction quality and reduce construction costs.

Application and analysis of innovative models in construction engineering management

With the continuous acceleration of China's industrialization process and urbanization construction, traditional engineering management models have gradually exposed various shortcomings and shortcomings, unable to adapt to the development of the new era. Therefore, exploring innovative models in engineering management has become particularly important. This article focuses on analyzing the characteristics and shortcomings of three traditional engineering management models that are widely used worldwide at present, and proposes corresponding analysis methods for them. Firstly, further improve the organizational system from the perspective of management system and establish a modern enterprise system and a responsible person system to fundamentally ensure the practicality of project management. Secondly, based on Building information modeling (BIM) technology, modeling and information collection are carried out for different management stages to achieve transparent and visual management, Further improve construction quality from a technical perspective, ensure construction progress, and improve management level. In summary, this article analyzes the problems of traditional models and analyzes the application of innovative models from two aspects. However, there are still issues that need to be addressed, such as different situations in different regions and insufficient information and data collection, in order to truly achieve the application of innovative models in engineering management.

Detecting temperature segregation in asphalt pavement construction using infrared imaging and deep learning

ABSTRACT Temperature segregation (TS) is the uneven distribution of mixture temperature during construction. Considering segregation patterns is essential to detect TS and evaluate construction quality. This paper collected infrared images and classified three segregation categories: interlaced TS, banded TS (BTS), and clustered TS (CTS) based on temperature distribution patterns. Detecting TS using infrared image and deep learning is benefit for improving construction quality, so we labelled the BTS and CTS images to form an original training dataset (OD) for deep learning detection algorithms. We also used two image augmentation approaches to expand OD and obtained two more datasets: dataset augmented without CutMix, which is a classic image augmentation method, and dataset augmented with CutMix (CD). Based on three datasets, we trained You Only Look Once version 5 (YOLOv5) models to detect TS and compared them with Faster R-CNN and YOLOv7. CDM-YOLOv5, YOLOv5 trained on CD, outperformed others, with a mean average precision of 71.5% and an F1 score of 69.7%. We also observed performance gains using the CutMix augmentation. The findings contribute to automating construction quality evaluation and control.

Achieving energy savings and early-ages strength enhancement of prefabricated cement components: Combined application of direct electric curing and sodium sulphate

Accelerated curing regimes are widely used to produce prefabricated concrete elements to improve construction quality and reduce time costs. A new accelerated curing regime, direct electric curing (EC), is proposed, and its effect on the performance of cement paste and energy consumption is discussed and compared with the common accelerated curing regime (steam curing). The results show that EC can significantly accelerate the early-ages hydration process of cement paste and increase its 1-d content of hydration products. The compressive strength (1–28 d) of the electro-cured specimen is higher than of the standard-cured sample, but its sorptivity coefficient and drying shrinkage value increases slightly due to the coarsening of the pore structure. EC can greatly improve the energy utilization efficiency in the process of curing cement sample, and its 1-d energy consumption per cubic meter of sample per MPa is only 3.65% of that in steam curing. In order to further improve the energy efficiency of EC, sodium sulphate (SS) is incorporated to the cement paste as a hardening accelerator. Incorporation of SS can further improve the early-ages strength of cement sample, making its 8-h compressive strength (1.5–2% SS) surpass the 1-d strength of steam-cured and electric-cured plain pastes. This means that the combined application of EDS and SS can not only shorten the demoulding time (saving time cost), but also further improve the energy utilization efficiency. The 8-h energy consumption (kWh/m3⸳MPa) of electro-cured cement sample after incorporating 1% SS is only 1.18% of that of steam curing and 35.8% of that of single EC. Under the synergistic acceleration of SS and EC, the energy consumed by curing prefabricated components is significantly reduced, which could lead to an energy revolution and promote sustainable development in building engineering.

Improving construction quality assessment

At the moment, the quality of construction work has increased significantly. This is due to the evolution of the construction industry as a whole. More modern technologies, high-quality construction equipment are used, automatic design systems have improved. A more demanding attitude of the customer and the buyer also improves the quality of construction work. At the same time, there are a number of serious negative factors that reduce the quality of work: a high proportion of government orders, outdated regulatory framework, traditional problems of the construction industry. All this does not allow the quality of construction to grow at a high rate. Reforming these points will help to increase the growth rate of quality.

DEVELOPMENT OF A QUALITY MANAGEMENT SYSTEM FOR PRECAST CONCRETE FACTORIES

The precast concrete (PC) method involves manufacturing reinforced concrete building components in a factory that are then transported to and assembled on a construction site. Compared to conventional methods, PC is widely employed as an advantageous means of creating a sustainable environment and improving construction quality. However, due to time and cost increase, many modern PC factories inspect only randomly selected component samples, for which they write inspection reports using paper-based forms. The storage and management of these documents associated with inspections within factories are essential because any defects that occur during the manufacturing process adversely affect the subsequent delivery and assembly activities. In this study, a mobile application capable of automated documentation and the storage, and input of systematic data was developed to generate a system for comprehensive quality management and assurance within PC factories. The developed system was tested in a PC factory, achieving a 47% time-saving rate compared to the conventional inspection method. Inspection reports of the developed system contain considerably more information than those of the conventional method and fundamentally prevent the risk of document damage and loss as they are automatically archived on a server in digital format.

Experimental Evaluation of Stiffness Properties of a Quicklime-Stabilized Clay Subgrade Using a Resistivity Plate Loading Testing Device

Quicklime-mixing in soil stabilization applications for subgrade construction is crucial to its engineering performance and controlling quicklime and water content. Modern construction quality control devices and methods have improved construction quality control substantially. Certain devices, meanwhile, still need to be studied more thoroughly. This study used the resistivity plate loading device to assess the physical and stiffness properties of compacted quicklime-stabilized subgrade instantaneously and simultaneously for compaction quality control. The Taguchi L9 orthogonal array was used to design the experiment considering the dry density, test time, quicklime, and water content at various input factor levels. The pH, cation exchange capacity, conductivity, X-ray diffraction analysis (XRD), and scanning electron microscope (SEM) tests were further conducted. Analysis of the Taguchi experiment shows that the average soil electrical resistivity responses increased with dry density, test time, and quicklime content, and were highest at low water content. Whether the dry density, quicklime content, and test time are positively or negatively related to the average subgrade reaction modulus depends on the level of the water content. Regression equations are proposed to predict the average subgrade reaction modulus and soil electrical resistivity. The tested soils’ pH, conductivity, and cation ion exchange capacity properties were directly related to the test time, water, and quicklime content. The XRD showed nearly similar X-ray diffraction peaks. The SEM analysis confirmed marked changes in the microstructure of the samples that explained the changes in electrical resistivity and subgrade reaction modulus responses. The test results show that the resistivity plate loading device efficiently assesses compacted quicklime’s stiffness and physical properties at ease and instantaneously.

Analysis of Building Construction Quality Control and Safety Management

Quality control and safety management are two very important contents in building construction project management. Once the construction quality is not up to standard or a safety accident occurs, the economic benefits of the project will be severely impacted. However, there are still some problems in the quality and safety management of the project. In this paper the problems in construction quality control and safety management are analyzed, and effective countermeasures are put forward, in hopes to help improve construction quality and safety.

Comparing and evaluating influence of nylon fiber and fly ash in self compacting concrete

Self-consolidating concrete (SCC) is a special concrete that is highly flow able, non-segregating and self-expanding. Self-compacted concrete (SCC) is poured into the formwork without compaction and fills the formwork by its own weight. SCC is considered to have many advantages. Compared with conventional concrete as improved Construction quality, faster construction activity, lower cost etc. This project was carried out to evaluate the effects of addition of nylon fiber and fly ash on the fresh and hardened properties of SCC mixes. In this project, concrete mixes with nylon fiber of 0.5%, 1.5%, 2.5%, and fly ash with 0%, 15%, 30% and 45% were used to determine its permeability, flow Capacity, evaluated on the basis of and separation resistance, slump flow, L-box and V-funnel tests. After 3 days, 14 days, 28 days of curing SCC cylinders, compressive and splitting tensile strength were tested. The test results show that nylon fibers increase permeability but decrease the filling capacity and segregation resistance of SCC. Furthermore, it can be concluded that after 3 days, 14 days, 28 days of curing, the test of concrete samples showed that the addition of nylon fiber up to 2.0% of cement by volume increased the compressive strength of SCC. Strength, improves tensile strength but 2.5%. Nylon fiber reduces the compressive strength, tensile strength of hardened SCC.

Multiobjective Optimization of a 3D Laser Scanning Scheme for Engineering Structures Based on RF-NSGA-II

To promote precision installation accuracy of engineering structural components and improve construction quality, point cloud data obtained by 3D laser scanning are widely used in construction quality monitoring. Reasonable parameters are very important to control errors and improve efficiency during the process of 3D laser scanning. Therefore, this paper proposes a random forest-nondominated sorting genetic algorithm (RF-NSGA-II) multiobjective optimization model with an elite strategy. To study the relationship between 3D laser scanning parameters and measurement errors or efficiency, the best scanning parameters are identified. In this paper, high-precision prediction of the relative error and scanning time by 3D laser scanning parameters is achieved by using an RF, and the nonlinear mapping relationship function is obtained, which is used as the objective optimization function. The RF-NSGA-II multiobjective optimization algorithm is developed to optimize the relative error and scanning time, and the scanning time is the shortest under the condition of reasonable relative error. Through this study, we can mainly draw the following conclusions: (1) based on the RF, we can obtain a prediction model of relative error and scanning time with high accuracy, in which the R2 (determination coefficient) value and root mean square error (RMSE) of the relative error prediction model are 0.967 and 0.0277, respectively, and the R2 value and RMSE of the scanning time prediction model are 0.978 and 0.0243, respectively; (2) optimized design parameters for 3D laser scanning of structural components are obtained, including a horizontal incident angle of 90°, an inclination angle of 90°, point cloud density of 3.2 mm, measurement distance of 3 m, resolution of 0.456, and visibility of 8.67 km; and (3) the RF-NSGA-II model developed can effectively reduce the relative error of the 3D laser (by 2.16 mm) and shorten the scanning time (by 148.926 s) compared with the average value. The structural components also meet the requirements in the deviation test. Therefore, the application of the RF-NSGA-II model in the assembly and fabrication of structural components can realize the intellectualization of the production process and improve the precision of the prefabrication of structural components, which has high engineering application value.

Application of Information Technology in Construction : A Case from Nepal

This study aimed to identify the functions of information technology (IT) in the development of the construction industry in Chitwan and Nawalparasi. The study utilized a 5-point Likert scale questionnaire survey administered to ten contractors and ten consultants in the area. The survey included remarks about how IT is used in the construction industry, and four areas of IT use in construction were established. The identified outcomes were evaluated using Relative Importance Index (RII) and Ranking. The study found that the operational level, design level, and official level of management were the three most important levels of management by the relative importance index analysis. The mobile phone, laptop, and desktop computer were the primary hardware devices utilized on-site, and Microsoft Office applications such as Excel, Project, PowerPoint, and Word were determined to be the most important applications used in site administration. The study concluded that IT is a critical tool for the administration and management of construction projects. The findings of this study are consistent with other research that highlights the importance of IT in the construction industry. Information technology is streamlining operations in the construction sector, improving construction quality and safety measures, and maximizing efficiency and reliance on data in construction. The adoption of data-driven technologies such as building information modeling (BIM) is transforming the construction industry. Modern technologies and construction software are helping to control the information and disseminate it so it can be available and useful to project teams. Overall, the use of IT in the construction industry is becoming increasingly important, and its benefits are clear. Keywords: construction, data, industry, information technology (IT), RII index

Assessment of Technical Capacity and Performance of Local Builders in Residential Building Construction Sites

Abstract This research aims to investigate the technical capability and performance of local builders on residential building construction sites in Gaindakot Municipality, Nepal. The construction industry plays a vital role in the growth of economies worldwide. The quality of construction heavily depends on the technical capacity and performance of builders involved in residential projects. This study aims to assess local builders’ technical competence and performance operating on residential building construction sites. By examining the capabilities of local builders, this research contributes to enhancing the overall quality and efficiency of residential construction projects. The research employs a mixed-methods approach, combining quantitative and qualitative data collection techniques. A comprehensive survey is administered to local builders to evaluate their technical knowledge, skill sets, and utilisation of modern construction techniques. Concurrently, on-site observations and interviews are conducted to gain insights into the actual performance of builders during different construction phases. The findings of this study shed light on the strengths and weaknesses of local builders in residential construction. The on-site observations and interviews offer qualitative insights into the practical application of skills, compliance with safety protocols, and adherence to project timelines. The outcomes of this research are intended to guide policymakers, industry stakeholders, and training institutions in formulating strategies to enhance the technical capacity of local builders. Bridging the identified gaps can improve construction quality, reduce project delays, and increase customer satisfaction. Additionally, the study emphasizes the need for ongoing professional development programs to keep builders updated with the latest construction techniques and standards.

ВІБРАЦІЙНА МАШИНА ДЛЯ ПІДГОТОВКИ ТА УЩІЛЬНЕННЯ ПОВЕРХОНЬ

Vibration plates belong to the means of small mechanization and are mainly used for layer-by-layer compaction of vari-ous materials, such as sand, gravel, bitumen mixtures, etc. Vibro-tamping methods are used in the technology of road surfaces construction and other constructures. Self-propelled vibrating slabs are also used in other construction processes, such as laying, backfilling trenches, land work and laying paving slabs. They provide effective compaction of materials using vibro-tamping methods. The article is aimed at determining the optimal equipment for compacting materials during the construction of small objects. The goal of the authors is to consider the choice of vibration plates and their working bodies that best meet the requirements and needs for compacting various materials on small construction sites. A detailed study of this aspect will achieve optimal results in the process of compaction and develop recommendations for choosing the best working bodies for specific conditions of construction work.Due to different operating conditions and surface characteristics, we need emphasize on the improvement of the compac-tion method for best results. In general, this analysis can make a significant contribution to the development of effective material compaction strategies in the construction industry, contributing to improved construction quality. The key area of research is to expand the knowledge of the interaction of the working body of the vibration plate with various types of compressible mate-rial. Analysis of different types of working bodies for different surfaces can improve the compaction process and provide optimal conditions for different types of building materials, taking into account their unique properties.To perform soil compaction, we developed a vibration machine with a replaceable working body. This design allows to choose the optimal working body for each type of working material and thereby improve the quality of the compaction. In general, this analysis can make a significant contribution to thedevelopment of effective material compaction strategies in the construction industry, contributing to improved construction quality.

Automatic evaluation of rebar spacing and quality using LiDAR data: Field application for bridge structural assessment

This paper proposes a framework to automatically quantify the quality of rebar placement in the field to improve construction quality and long-term durability of the bridge structures. In this study, three-dimensional point clouds of a concrete bridge construction site were acquired using a mobile LiDAR scanner. Additionally, two algorithms, including projection algorithm and slicing algorithm, were developed to automatically extract the bridge rebar locations for layout quantification at the global level, bin level, and local level. Subsequently, LiDAR extracted rebar placement quality was compared to design drawings to investigate the effectiveness. This study also evaluated the quality of other concrete deck components, which include formwork panels and the contact surface between rebars and anchor bolts. The research revealed that the proposed framework can inform the rebar placement quality in the field prior to concrete pour, providing a permanent record of the bridge deck quality for future inspections and assessments.

Characterization of interlayer mechanical performance of double-layer porous asphalt compacted by three methods: Simulations and observations

The compaction method directly governs the interlayer patterns, which significantly influence the performance of asphalt pavement. The objective of this research aimed to investigate the interlayer mechanical performance of double-layer porous asphalt (DLPA) samples compacted by three methods: hot-on-cold (HoC), hot-on-warm (HoW), and hot-on-hot (HoH). The interlayer patterns at the upper-lower layer interface of DLPA samples were measured by the thin aluminum sheet and oil-saturated paper and characterized by the modified Weierstrass-Mandelbrot (W-M) function with two fractal parameters. The virtual direct shear test and pull-off test were conducted on the simulated DLPA samples incorporating interlayer patterns. The interlayer mechanical strengths from simulation were verified by laboratory experiments. The results showed that the fractal dimension and scale parameter in the modified W-M function characterized the interlayer patterns. The DLPA samples using HoH compaction exhibited the highest shear and tensile strengths that were inversely proportional to the fractal dimension, owing to the interlocking interlayer pattern generated. The HoH method was recommended to compact the DLPA pavement if the double-layer asphalt paver was available. The findings are useful to improve construction quality of the DLPA pavement.