Research and Application of QR Code Technology in High-Strength Bolt Construction Quality Control

Original: https://cli.im/article/detail/1931

Abstract: As a connection form between steel bridge member units, the construction quality of high-strength bolts directly affects the structural safety of the bridge and its operational safety during service. Therefore, controlling the construction quality of high-strength bolts is key to the quality management of steel bridge construction. Through the analysis and research of QR code technology, this paper applies QR codes to the quality control of high-strength bolt construction. Starting from three aspects—operators, torque wrenches, and on-site construction management—it briefly elaborates on the research and construction application of QR code technology in high-strength bolt construction quality control, providing a reference for similar projects in the future.

During bridge inspections in the operational phase of steel bridges, it is often found that high-strength bolts in structural connections are prone to loosening or even missing, seriously affecting the structural safety and operational safety of the bridge. Therefore, the construction quality of high-strength bolts is a key focus in the control process of steel bridge construction. In the construction process of high-strength bolts, the management of personnel, equipment, on-site construction progress, and quality often lacks integration, the quality inspection system is singular, lacks correlation, and the traceability of construction is poor. How to optimize the on-site construction quality management model of high-strength bolts and comprehensively improve the control level is key to engineering construction and the core of construction quality control.

1. Brief Description of High-Strength Bolt Construction Process

The construction process of high-strength bolts mainly includes: construction preparation, high-strength bolt installation, bolt tightening, and torque inspection.

(1) Construction preparation is generally divided into document preparation, technical preparation, equipment preparation, and on-site preparation.

Document preparation: Organize construction documents for high-strength bolts, including manufacturer self-inspection reports, factory certificates, and sampling inspection reports.

Technical preparation: Conduct safety and technical briefings and on-site practical training for operators before construction.

Wrench preparation: Calibrate torque wrenches daily before high-strength bolt construction and recheck them after construction.

On-site preparation: Before high-strength bolt construction, trim and clean bolt holes to ensure no burrs around the holes and no stains inside.

(2) High-strength bolt installation. Insert the high-strength bolt through the bolt hole and install the nut on the other side, paying attention to the orientation of the washer during installation.

(3) Bolt tightening. High-strength bolt tightening is generally divided into initial tightening and final tightening. The initial tightening torque is usually 50% of the design torque, and the final tightening is the design calculation torque value. After initial and final tightening, mark the bolts with different colors.

(4) Torque inspection. Use a specialized inspection wrench for quality inspectors to check the tightening torque of nodes according to the inspection frequency requirements.

2. Analysis of High-Strength Bolt Construction Quality Control

For on-site quality control of high-strength bolt construction, combined with the bolt tightening process, the focus is on three aspects: operators, torque wrenches, and on-site construction management. Among these, operator management is key, torque wrench management is a guarantee, and on-site construction management is the core. Any problem in the control process will directly affect the construction quality of high-strength bolts and have a serious impact on the overall structural safety of the bridge and its operational safety during service.

2.1 Proposed Control Model

(1) Intend to use QR code technology to achieve on-site identification and verification of operators, digitally marking personnel briefings and training for easy on-site management verification, and controlling the construction quality of high-strength bolts from the source.

(2) Intend to use QR code technology to achieve digital transmission of torque wrench information and data, digitally recording the basic information, calibration information, and construction information of wrenches, facilitating technical information verification and traceability query of bolts tightened by the wrench.

(3) Intend to use QR code technology to achieve digital transmission and traceability of high-strength bolt construction progress and quality management information, enabling managers to grasp the construction progress, quality, and inspection status of high-strength bolts anytime and anywhere, with timely, accurate, and efficient information and data transmission.

2.2 Principles of QR Code Technology Application

(1) The application of QR code technology in high-strength bolt construction management must have a good management operation system and backend construction modules.

(2) Information input in the construction management QR code module must be true and accurate.

(3) Information input for torque wrenches and construction progress and quality management QR codes must be timely and effective.

(4) QR code identifiers set on-site must be concise, elegant, clear, and intuitive, and installed firmly and reliably.

(5) Electronic QR codes must be transmittable through platforms like WeChat and QQ, achieving multi-channel scanning and identification functions.

3. Research on Quality Control QR Code Technology

3.1 Operator Management

High-strength bolt construction personnel are mainly managed by wearing safety helmets with QR code identifiers. Before construction, operators receive safety education, technical briefings, and practical training. Using the QR code system, operator information is input into the identification code, and then specially made safety helmets with QR code identifiers are issued to the corresponding operators. During on-site construction, high-strength bolt construction personnel must wear these special safety helmets for identity and information identification, as shown in Table 1.

3.2 Torque Wrench Management

Torque wrenches are mainly managed by setting QR code identifiers on the wrenches. Establish a wrench QR code management module, generate identification codes after the wrenches arrive on-site, and set them on the sidewalls of the wrenches. Complete the input of basic wrench information. During on-site construction, after daily calibration upon issuance, input all calibration information of the wrench into the system, and mark the initial or final tightening and the bolt specifications tightened by the wrench on the identification code. During on-site high-strength bolt construction, input the information of bolts tightened by the wrench into the system. During re-inspection upon warehouse return, input all re-inspection information into the system. If the re-inspection fails, clearly mark it and take timely measures, as shown in Table 2.

3.3 High-Strength Bolt Construction Management

On-site construction management mainly includes progress management and quality management, primarily controlled through QR code identifiers. Before construction, establish a high-strength bolt construction management QR code module based on the steel beam structural unit, generate QR code identifiers and set them on the bridge structure. Simultaneously, generate electronic QR codes for convenient information transmission and access.

During the bolt construction of the steel beam unit, input the on-site construction progress information of high-strength bolts into the system according to the workload or time nodes. After bolt quality inspection is completed, input the quality inspection and reporting status into the system. In progress management, the module automatically generates the progress completion ratio based on the number of bolts completed. The quality inspection system provides an evaluation of quality pass or fail based on actual inspection conditions, as shown in Table 3.

4. Construction Application of QR Code Technology

In the management process of high-strength bolt construction operators, on one hand, operators who have passed education and training are uniformly issued safety helmets with QR code identifiers, making it easy for engineering construction managers to identify and control personnel during construction management. On the other hand, by scanning the QR code identifiers on safety helmets on-site, basic information of operators can be accurately obtained, facilitating on-site verification and safety and technical control of construction personnel. This standardizes the management of high-strength bolt operators and improves the source control of high-strength bolt construction technology, as shown in Figures 1 and 2.

In the construction management process of high-strength bolt tightening wrenches, on one hand, intuitive information on the QR code indicates the bolt specifications tightened by the wrench and initial/final tightening, achieving unique labeling for wrench construction and accurate construction. On the other hand, scanning the QR code can obtain detailed calibration information of the wrench, facilitating on-site recording and inspection by quality inspectors. Additionally, if the torque exceeds the standard during re-inspection upon warehouse return, the wrench QR code system can promptly obtain the information of bolts tightened by the wrench that day, facilitating on-site re-inspection. The wrench QR code management system ensures the quality control of high-strength bolt tightening from the technical aspect of equipment and improves the on-site construction traceability of wrenches, as shown in Figures 3 and 4.

The application of the high-strength bolt construction management QR code system in steel beam unit construction uses the system to generate QR code identifiers and set them on the steel beam wall panels, while simultaneously generating electronic identification codes transmitted to public platforms like WeChat. After high-strength bolt construction is completed, dedicated personnel promptly input construction information. By scanning the on-site QR code identifiers or electronic codes, information such as construction progress, quality inspection, and reporting of high-strength bolts in the steel beam unit can be obtained. Additionally, entering the steel beam unit module allows detailed understanding of initial and final tightening times and personnel information for each node, as shown in Figures 5 and 6.

5. Conclusion

With the development and progress of science and technology, we have entered an era of digital, informational, and diversified management. Through the research on QR code technology, the project applies QR code technology to the management of high-strength bolt construction, not only improving the on-site construction quality of high-strength bolts but also establishing good correlations among operators, torque wrenches, and construction progress and quality management through the application of the QR code digital module system. Construction information transmission is timely, accurate, and highly traceable. The application of on-site QR codes and electronic transmission QR codes enables managers to understand construction progress and quality anytime and anywhere, making management both efficient and rigorous. This is worthy of further promotion and application in similar high-strength bolt construction quality control in the future.

References:

[1] JGJ 82—2011 Technical Specification for High-Strength Bolt Connections of Steel Structures [S].

[2] JTG/T F50—2011 Technical Specifications for Construction of Highway Bridges and Culverts [S].

[3] Liang Guicai. Application of Innovative QR Code Technology in Construction Management [J]. Architecture Technology, 2015, (46): 159–160.

[4] Zhang Tao. Exploration and Practice of Quality Traceability System Based on QR Code Technology in Construction Engineering [J]. Construction Safety, 2015, (5): 12–14.

[5] Liu Miao, Ning Kai, Kong Lingzhou. Design and Construction Application of Cable Crane System for Composite Beam Cable-Stayed Bridge [J]. Highway, 2018, (4).

[6] Ning Kai, Gao Quan, Liu Ying. Design and Construction Application of Lifting Tackle for Composite Beam of Lancang River Bridge [J]. Highway, 2018, (4).

Authors: Ning Kai, Li Hairui, Liu Ying (CCCC Second Highway Engineering Co., Ltd. Second Engineering Co., Xi'an 710065) Source: "Automobile Technology & Materials", November 2018