Article Selection | Application of Green Construction Technology in Large Public Building Projects

This article takes the passenger overnight accommodation in the expansion and renovation project of Changsha Huanghua International Airport as an example to elaborate on the project's green and low-carbon construction. It integrates a smart construction site management platform, "BIM+4D" information management, a construction project carbon emission quota calculation and analysis management system, green building materials, "10 New Technologies in the Construction Industry (2017 Edition)", green construction promotion and application technologies, and multiple independently innovated green low-carbon technologies. While ensuring project quality and safety, it effectively reduces carbon emissions, saves resources, protects the environment, and achieves significant comprehensive green benefits including economic, environmental, and social aspects. It also significantly improves the score for the three-star building rating, providing reference and experience for similar green building construction and green building rating evaluations.

 

Project Overview

 

The Changsha Airport expansion and renovation project is located on the east side of the existing Huanghua Airport in Changsha City, Hunan Province. It is one of the first nine green construction pilot projects in Hunan Province and a key project in the national and Hunan Province's 14th Five-Year Development Plan. Upon completion, it will reshape the transportation pattern in central China, systematically upgrading its transportation network, regional economy, technological innovation, and sustainable development. The comprehensive transportation hub project is its first phase, with the accommodation building providing passengers with short-term lodging, dining, meetings, and other comprehensive services. The total building area of the accommodation is 79,000 m ² , featuring a frame structure with 6 floors above ground and 1 floor underground. The design target is a three-star green building, requiring construction measures closely linked to the design to increase the star rating score. The overall rendering is shown in Figure 1.

The project aims to win major awards such as the China Construction Engineering Luban Award (National Quality Project), with high construction quality requirements. The construction area is adjacent to the flight zone, as shown in Figure 2, requiring non-stop flight construction with high green construction environmental standards. The accommodation building overlaps with several unit projects, with difficult foundation pit excavation, numerous "pit-in-pit" situations, frequent workface handovers, making on-site organization and coordination extremely challenging, and mobile communication signals are heavily interfered with.

 

 

Green Low-Carbon Construction Technology - Information Technology

 

Smart Construction Site Management System:

The project uses a full-chain command system as the smart construction site management platform, linking computers of various departments, management personnel's mobile software, walkie-talkies, and smart safety helmets, on-site cameras, environmental monitoring equipment, deep foundation pits, high formwork, concrete curing temperature and humidity sensors, and other monitoring instruments to comprehensively control the quality, safety, green civilized construction, cost, and progress of the construction site, implementing precise command and coordination. Among them, 8 sets of environmental monitoring systems (as shown in Figure 3) monitor real-time air temperature and humidity, total suspended particulates (TSP, PM _2.5 , PM ₁₀ ), noise, and other environmental indicators at the construction site, linked with an automatic sprinkler system. When the monitored air suspended particulate matter exceeds the set value, the command center can automatically activate sprinklers for dust suppression; when other pollutants exceed standards or stress and deformation approach warning values, the system sends warning messages to relevant management personnel for timely measures. Meanwhile, the smart construction site management platform also connects with commercial concrete stations, machinery rental parties, material suppliers, and other partners through "5G + IoT," to monitor the transportation and usage of machinery and materials in real time.

Construction Project Carbon Emission Quota Calculation and Analysis Management System:  

The project actively participates in various carbon reduction research topics, analyzing and summarizing the characteristics and patterns of carbon emissions during construction, collecting carbon emission factors for various machinery shifts and building materials, and developing a complete carbon emission calculation and scheme comparison management system. One of the research outcomes is the Construction Project Carbon Emission Quota Calculation and Analysis Management System, the first complete, convenient, traceable, and full-process dedicated software for construction project carbon emission calculation and analysis in Hunan Province. It covers housing construction, decoration, electromechanical installation, municipal water supply and drainage, landscaping, and other sectors. Its core calculation module uses the carbon emission coefficient method based on GB/T 51366—2019 "Building Carbon Emission Calculation Standard" and references construction project costing methods and construction quotas to build a carbon emission quota calculation model. It can achieve "one-click carbon calculation" for three stages: building material consumption (material production), material transportation, and construction. It also enables seamless output from carbon budgeting, carbon reduction to carbon settlement. Evaluated by the Hunan Green Building and Steel Structure Industry Association, the overall level reaches international advanced standards, with the carbon emission factor algorithm based on engineering quotas and the multi-dimensional building carbon emission benchmark calculation method reaching international leading levels. During construction organization and construction plan design, this software is used to calculate and analyze carbon emissions, comprehensively considering quality, safety, cost, progress, and other factors to determine the most advanced and applicable plan.

 

BIM Deep Assistance:  

The project adopts BIM forward design, integrating design, construction, and operation & maintenance phases. During construction, the BIM collaborative management platform integrates big data, IoT, and other construction methods, using BIM+4D technology for multi-disciplinary standardized collaborative modeling. It effectively carries out drawing reviews, site layout, plan formulation, detailed design, material quantity calculation, timely identifying and correcting interdisciplinary clashes, controlling construction progress and risks, and reducing material waste. During the three-level technical safety disclosure, 3D models and animations are used to vividly explain construction steps to the personnel receiving the briefing.

During the excavation of the deep foundation pit earthwork, due to proximity to the flight area, oblique photography technology cannot be used to generate terrain. Therefore, based on the survey results at site handover, the project uses BIM+Civil3D methods to accurately and efficiently calculate and verify the total earthwork volume. Its high precision and visualization advantages ensure construction quality and efficiency.

For non-stop flight construction, during the design of the tower crane group, because the airport limits the construction area height to 104 m and the deep foundation pit imposes load restrictions on surrounding areas, and due to the large workload of tower cranes and frequent workface handovers, the project uses BIM+4D technology to assist in designing the tower crane group scheme, as shown in Figure 4. It precisely arranges tower crane positions, coverage, horizontal distances, erection heights, and height differences between adjacent cranes, scientifically designs the hoisting sequence and handover steps, and conducts collision avoidance analysis for the tower crane group. This avoids collision accidents or interference with normal aircraft takeoff and landing during actual construction, while efficiently utilizing each tower crane. This BIM deep assistance measure can achieve the highest score of 15 points in GB/T 50378—2019.

 

 

Green Low-Carbon Construction Technology - Green Building Materials

 

During the selection of raw materials for the project, green building material labels were included in the assessment scope and written into the contract. The proportion of green building materials used in the main structure reached 91.4%, exceeding the highest value of 70% in GB/T 50378—2019, earning the maximum score of 12 points. Meanwhile, the project sourced materials locally, with building materials within a 500 km radius accounting for 99.2% by weight, surpassing the 60% control requirement in GB/T 50378—2019. The project's centralized steel processing workshop used fully automated equipment to process various steel products, and coordinated with the ready-mix concrete plant to establish stations close to the construction area. These measures effectively ensured the quality and supply efficiency of raw materials. Adhering to the concept of low-carbon concrete, a high proportion of industrial waste such as fly ash and slag powder was used in concrete raw materials, effectively improving the workability of fresh concrete and the mechanical and durability performance of hardened concrete. During material use, the project strictly followed the quota-based material requisition system combined with BIM layout optimization, controlling the wastage rates of steel, concrete, and masonry bricks to 1.12%, 0.58%, and 1.23% respectively, far below the quota wastage rates and project target values, earning up to 8 additional points according to GB/T 50378—2019. Waste materials generated during steel processing, concrete pouring, bricklaying, and mortar masonry were centrally managed and redeployed through a smart construction site management platform, achieving a recycling rate of 98.28%, exceeding the 50% requirement in GB/T 50378—2019, earning 4 additional points.
 

 

Green Low-Carbon Construction Technology - Technological Innovation

 

The project actively promotes the use of new technologies, new materials, new equipment, and new materials, adopting 9 major items and 25 sub-items from the "10 New Technologies in Construction Industry (2017 Edition)" and 10 major items and 31 sub-items from the "Green Construction Promotion and Application Technology (2017 Edition)". On this basis, the project continuously innovates and improves green low-carbon construction technologies to address key and difficult points on site.

 

Screw Pile Drilling and Soil-Displacement Bored Pile Technology:  

Within the foundation area of the building, some soil layers are fill layers. To address issues such as poor homogeneity, high void ratio, and low strength caused by incomplete self-weight consolidation, the project used a self-designed patented product—the screw soil-displacement drill bit—during pile foundation drilling. By applying rotational and vertical forces, the soil is spirally compressed into the soil layer, with most soil particles pressed into the surrounding soil pores, forming a highly compacted soil layer about 30 cm around the pile hole, achieving self-supporting pile walls. A small portion of soil is pressed into the drill bit blades and lifted out of the hole. If cavities, solution holes, or solution channels are encountered during drilling, local materials such as soil, rubble, brick debris, and concrete that meet requirements are backfilled and pressed into the cavities to reinforce the pile walls. Compared with traditional slurry wall protection and steel casing protection, this method effectively increases pile side friction, improves single pile bearing capacity, reduces pile foundation settlement, decreases soil export volume and concrete filling coefficient, and reduces pollution such as slurry, dust, and noise. This technology ensured smooth pile foundation drilling, reduced costs by 3.26 million yuan, and cut carbon emissions by 605 tons.

 

Heavy and Extra-Long Steel Cage Single-Crane Overall Lifting Construction Technology:  

To address the characteristics of pile foundation steel cages being both long and heavy, the project designed a special pulley set that increases the lifting range by adding an auxiliary hoist guide wheel at the same horizontal position as the original guide wheel. Combined with a specially designed spreader bar and corresponding tonnage steel wire ropes and U-shaped rings, after calculating the lifting points of the steel cage, the entire steel cage can be lifted using only one crane. Compared with sectional lifting or using two or more cranes for overall lifting, this heavy and extra-long steel cage single-crane overall lifting technology offers advantages: the steel cage can be fully fabricated in the centralized steel processing workshop, ensuring better quality; simple on-site operation ensures the steel cage does not deform while guaranteeing safety, accelerating progress and saving costs. After pile formation, ultrasonic testing and core sampling tests confirmed that pile integrity and single pile shear bearing capacity met design requirements. Compared with traditional wellhead welding methods, this technology saved a total of 1,600 hours of welding time, reduced labor costs by 360,000 yuan, and cut carbon emissions by 12 tons.

 

Triangular Truss Steel Formwork Combined Shoring System Construction Technology:  

To address difficulties such as high exterior wall heights, varying pouring heights, high concrete appearance quality requirements, and tight schedules, the project used an improved triangular truss plus steel formwork shoring system. The system uses a combination of 3.1 m + 2.0 m + 1.0 m steel formwork modules, adaptable to different pouring heights and reducing self-weight. Large steel panels ensure smooth surfaces with fewer joints. The shoring system is equipped with universal wheels underneath, allowing it to move within the foundation pit using manpower or small winches, avoiding the need for large cranes and transport vehicles to lift formwork in and out during assembly and disassembly. Two sets of the shoring system were used for the entire concrete pouring process of the building's exterior walls on the east and west working faces, achieving saturated operations without delays. Formwork and concrete construction proceeded smoothly, with qualified concrete quality and smooth, flat appearance. Compared with traditional wooden formwork and small steel panels, this shoring system reduced construction costs by 14% to 22%, cut carbon emissions by 39 tons, and accelerated the project schedule by 41 days.

This shoring system was also used in other unit projects of the Changsha Airport expansion project, especially in the Changsha Maglev East Extension connecting to the T3 terminal building, where the Maglev T3 station's exterior walls have multiple heights and no haunches. The three-layer support inside the deep foundation pit obstructed formwork lifting, making the system's modular and self-moving features particularly advantageous here. Through unified scheduling via the smart construction site management platform, the construction schedule of the building's exterior walls was seamlessly linked with other working faces. The advantages of multi-use formwork and on-site turnover further reduced amortization costs and carbon emissions.

 

Comprehensive Crack Control Technology for Extra-Long Concrete Exterior Walls:

The exterior wall of the building is an ultra-long concrete structure with dense reinforcement, and the wall surface faces the prevailing wind direction throughout the year. Due to the stability of the foundation pit, narrow working space, and tight handover time, the compartmentalized construction method was chosen. To address the common issue of cracking in ultra-long concrete structures, the project adopted a series of technologies throughout the entire concrete construction process to control cracks caused by three factors: temperature difference inside and outside the structure, concrete shrinkage, and external structural constraints. When selecting concrete raw materials, the performance of the materials themselves was considered, as well as the synergistic effect of combining materials ("1+1>2"), such as double admixture of secondary fly ash and S95 mineral powder combined with a retarding high-efficiency water reducer. During mix optimization, the design followed standards of high slump, high penetrability, low workability loss, and low shrinkage, using a low water-cement ratio and adjusting the expansion agent's compensation for shrinkage to match the concrete's shrinkage development. Thermal insulation began during transportation from the ready-mix plant, formwork curing started immediately after pouring, and insulation and moisture curing began at final set. The concrete curing employed intelligent information-based methods, utilizing the concrete's self-heating and using curing water stored underground with relatively stable annual temperature to reduce the rate of temperature difference change between inside and outside the structure. Layers of plastic film, insulation blankets, and windproof colored strip cloth were used for insulation. During curing, the smart construction site management platform received real-time data from temperature and humidity sensors pre-installed at representative locations on the exterior wall, controlling the automatic sprinkler system for water replenishment or sending alerts to on-site managers to check insulation facilities. Compared to isolated approaches focusing on a single process or method, or ignoring specific working environments and simply stacking multiple methods, this series of technologies can precisely and economically allocate human, machine, and material resources, especially suitable for ultra-long concrete structures requiring continuous pouring in a short period. During the exterior wall pouring and curing process, the maximum concrete temperature and internal-external temperature difference met requirements, and no temperature-difference-induced crazing cracks appeared after formwork removal. Observations one month after pouring showed a 30%-50% reduction in crack quantity compared to similar surrounding buildings, with through cracks reduced by over 60% in total length. The degree of concrete alkali efflorescence was lighter. Before completion, crack repair costs could be reduced by 900,000 yuan and carbon emissions by 1.21 tons, with an expected reduction of 8 million yuan in crack repair costs and 10.75 tons of carbon emissions over the entire service life.

 

 

Green Value Creation

 

The comprehensive benefits created by green and low-carbon construction technologies are significant and have effectively improved the evaluation score of the three-star green building rating. The calculated carbon emissions totaled 38,902 tons, and after optimizing and improving construction methods, cumulative carbon reduction reached 3,368 tons, achieving a carbon reduction rate of 8.7%. Each construction site operated efficiently with smooth coordination, achieving a 100% first-time quality acceptance rate. No major safety incidents occurred. Actual construction progress was 32 days ahead of the planned schedule. Emissions of various pollutants were properly controlled, with no impact on flight area operations and no complaints received. The project team effectively utilized waste concrete, sand, and gravel construction debris, reducing a total of 4,364 tons. This not only reduced the use of externally transported materials but also effectively alleviated traffic congestion around the flight area. The building currently has a preliminary evaluation score of 89.3, meeting the requirement of "Three-star green building ≥ 85 points" in GB/T 50378—2019.

 

 

 

Citation format: Ouyang Zhi, Zhang Mingliang, Wang Jiangying, et al. Application of Green Construction Technology in Large Public Building Projects: A Case Study of the Passenger Overnight Accommodation Project at Changsha Huanghua International Airport [J]. Green Building, 2025, 17(4): 18-22.