Structural Materials Commons^™

Influence Of Loading Methods On Compression Modulus Of Red Sandstone Soil Solidified With Biological Enzyme And Cement, He Liang, Zhang Haixiang, Guan H Ongxin, Li Huili, Yang Hairong, Liu Hongfu

Journal of China & Foreign Highway

There are various methods to test the modulus of cement-stabilized mixtures.The stiffness performance of cement-stabilized materials will be affected after adding biological enzymes.In order to systematically analyze the influence of loading conditions on the compression modulus of the red sandstone soil solidified with biological enzyme and cement，compressive modulus tests were conducted on the red sandstone soil solidified with biological enzyme and cement by using three static modulus test methods including monotonic loading method of middle section，stepwise loading and unloading method of top surface，and stepwise loading and unloading method of middle section，as well as dynamic modulus method of top surface and …

Optimization Of Mix Proportion For New Jersey Precast Concrete Safety Barriers And Performance Tests Under Integral Concrete Vibrating, Chen Lin, Li Beian, Li Yuanrui, Zhao Zixiang

Journal of China & Foreign Highway

New Jersey safety barriers are the most commonly used form of guardrails in highway median separators due to their excellent safety protection.In response to the cost reduction and quality improvement，efficient and rapid preparation process，and quality issues of New Jersey precast concrete safety barriers，this article adopted the automation production process of New Jersey precast safety barriers，optimized concrete mix proportion for precast safety barriers，and studied their performance.The experimental results show that in the designed C 30 concrete，the compressive strength of the concrete mixed with 15% fly ash reaches 39.2 MPa，and th e slump reaches 185 mm.The concrete performance meets the requirements of …

Experimental Study On Shear Behavior Between Nrc‑Uhpc Interface, Chen Zhenkan, Li Junsheng, Shi Quan, Fang Haozhen, Mo Fan, Jiang Haibo

Journal of China & Foreign Highway

In order to investigate the effect of the screw diameter of planted bars and ultra-high performance concrete （UHPC） pouring method on the shear behavior of normal reinforced concrete （NRC） and UHPC， two groups of six push-out specimens were designed for shear behavior tests.The results show that after the failure of the concrete bonding force in the NRC-UHPC interface，the screw can maintain shear behavior so that the failure process of the specimen after the load reaches the peak shows ductile characteristics.For specimens with screw diameters of 12 mm and 16 mm，greater screw diameter indicates higher shear capacity of the specimens and …

Design And Construction Process Of Cross‑Beam Supports For Main Tower Of Changtai Changjiang River Bridge, Zeng Jian, Hu Pei, Wang Chao

Journal of China & Foreign Highway

The construction of the lower cross-beam structure of the main tower of Changtai Changjiang River Bridge has the characteristics of high construction height，large amount of concrete earth volume，and difficult control of down-warping deformation.In order to implement the pouring of the lower cross-beam of the main tower，floor-type steel pipe supports were set at the lower cross-beam，which were used to support the lower cross-beam formwork and bear the load during the concrete pouring.Through the finite element software analysis and calculation，it was found that the asymmetric deformation of the main structure of the lower cross-beam could be effectively controlled，and the overall force of …

Determination Of Manufacturing Parameters Of Large Section Of Continuous Steel Box Beam With Variable Section In Shenzhen‑Zhongshan Passage, Dong Chuangwen, Chen Long, Li Chuanxi

Journal of China & Foreign Highway

Accurate calculation of manufacturing parameters is the key to the efficient，high-precision，and rapid installation of large sections of continuous steel box beam bridges.Taking the steel box beam with the variable section in Shenzhen-Zhongshan Passage as the background，this paper first established a finite element model of the beam element in the whole construction process to obtain the pre-camper.Secondly，the average neutral axis position was calculated based on the height of the neutral axis of each beam section.Then，according to the deformation characteristic that the beam length remained unchanged at the mean neutral axis，the pre-camber was superimposed at the mean neutral axis to get the …

Key Technology For Construction Of New Single‑Wall Steel Suspended Box Cofferdam With High Pile Tied Beams In Deep Water, Yang Jinlong, Zhao Lin, Jiang Qunlong

Journal of China & Foreign Highway

In order to ensure the safe，efficient，and economical completion of the construction of the high pile tied beam of Muping Xiangjiang River Bridge in deep water，a new type of single-wall steel suspended box cofferdam was designed to act as the water retaining and enclosure structure during high pile tied beam construction according to the characteristics of deep water level and shallow stratum cover layer at the high pile tied beam location.Through the innovative design of steel casing on the bottom of the steel suspended box cofferdam，the design height of the wall panel and the amount of steel input were reduced.On the …

Influence Factors Of Carbonization Of Tunnel Segment Structure And Life Prediction Analysis, Li Dongbiao, Miao Miao, Shen Caihua, Chen Wei

Journal of China & Foreign Highway

There are many factors that affect the carbonization life of concrete segments in underwater tunnels，and the prediction methods are not uniform.In this paper，combined with actual engineering，the influencing factors and laws of carbonization of concrete segments in underwater tunnels were analyzed，and three methods for predicting the life of concrete segments were established with the crack limit as the control target.The prediction results of the three methods were compared.The results show that the influence of the temperature and CO2 concentration in the tunnel predicted by the three methods on the life of the tunnel lining structure is basically consistent with the existing …

Key Technology For Incremental Launching Construction Of Double Guide Beam Of Steel Box Girder, Sun Xiaoqiang, Yue Xinxing

Journal of China & Foreign Highway

By taking the incremental launching construction of the steel box girder at the 6th hole of the approach bridge of Baoji Taigu Bridge as the engineering background，the original plan adopted single-guide beam multi-point walking incremental launching technology for assembly and incremental launching on the prestressed reinforced concrete beam of the adjacent hole.Since the middle span of the concrete beam cannot withstand the concentrated force at the incremental launching points，the multi-guide beam multi-point walking incremental launching technology was finally used to arrange the incremental launching points at the transverse diaphragm plate of the end of the concrete beam.By increasing the incremental …

Emergency Vehicle Dispatching Model Considering Demand Urgency And Delivery Fairness, Long Kejun, Liu Jia, Gao Zhibo, Chen Suqian, Zhang Zhonggen

Journal of China & Foreign Highway

In emergency vehicle dispatching after unexpected events，it is crucial to prioritize critical nodes with high demand urgency while minimizing excessive delivery delays at other nodes to prevent secondary impacts.On this basis，this study developed an emergency vehicle dispatching model that considered demand urgency and delivery delay fairness.Firstly，the entropy weight-TOPSIS method was used to calculate the demand urgency for each node，and a delivery delay balance index was introduced to minimize disparities in delivery delays between nodes.Secondly，a multi-objective optimization model was established with total delivery time，overall cost，and delivery delay balance as objectives，while considering constraints such as inventory levels at distribution centers and route …

Working Properties Of Steel Tube Batter Piles With Concrete Infill Based On Abaqus, Yang Meiliang, Li Liemin, Sun Kunjiang, Han Rui, Zhong Yang

Journal of China & Foreign Highway

In order to explore the respons e characteristics of steel tube batter piles with concrete infill under vertical load，the steel tube batter pile with concrete infill used in Saribas Bridge in Malaysia was taken as the research object.Based on the numerical simulation method，the frictional resistance of the inner and outer walls of the steel tube，the frictional resistance around the pile at the section，and the bending moment bearing ratio between the steel tube and the concrete core of this type of batter pile under vertical load were studied.The results show that the passive-side frictional resistance of the 0–15 m pile section …

Neural Operator And Physics-Informed Deep Learning Approaches For Inverse Design Of Composites And Manufacturing Processes, Minglei Lu

All Dissertations

In this dissertation, artificial intelligence (AI) models are designed and used to accelerate inverse design of composites and manufacturing processes. The critical bottlenecks in machine learning (ML) including data availability, data quality, model generalization and adaptation, interpretability, physical consistency, and the ’black box’ nature of models for the inverse design are addressed. And the proposed AI models are tested under different engineering scenarios. Firstly, a fast deep neural operator (DNO) structure was developed to significantly reduce training time. This model was tested in the context of additive manufacturing, a transformative industrial technology that allows for the creation of materials with …

Anti-Corrosion Performance Of Magnesium Potassium Phosphate Cement Coating On Steel Reinforcement: The Effect Of Boric Acid, Fan Zhang, Jihui Qin, Kangyi Cai, John J. Myers, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It has recently been found that magnesium potassium phosphate cement (MKPC) paste coating applied on the surface of steel reinforcement can effectively retard the onset of corrosion and suppress corrosion reactions. However, the fast-setting nature of MKPC—which is a merit in repair—can be problematic in a practical engineering process of coating the steel reinforcement with MKPC paste. To address this problem, boric acid (H₃BO₃) was added as a retarder in an MKPC formulation to prolong the setting time. This work investigated the impact of boric acid (at 5% by weight of MgO) on the anti-corrosion performance …

Development Of Multifunctional Wood Composites With Integrated Phase Change Materials For Enhanced Thermal Management, Self-Healing, And Sustainability., Emmanuel Igbokwe

LSU Master's Theses

Abstract

This study focused on incorporating self-healing, flame retardancy, and energy harvesting capabilities into the wood composite to contribute to more sustainable and energy-efficient building practices. Oriented strand board has been widely used as sheath for roofing or dry walls in residential buildings. Residential buildings account for a large portion of energy consumption. Therefore, an oriented strand board with energy harvesting capability is highly desired. Additionally, flame retardancy and damage self-healing and end-of-life recycling are also critical features for buildings.

In this study, we prepared a novel oriented strand board by constructing sandwich structures. The face sheets of the sandwich …

Treatment Methods Of Unstable Expansive Soil Slope Excavation In Overlying Rock Layer In Alpine Region, Shi Xiaobo, Cui Guangyan, Mou Chao, Wen Ye, Xie Feng, Fu Xiaoyang

Journal of China & Foreign Highway

To deeply study the treatment method for instability of highway cutting slope under the condition of expansive soil overlying rock layer in an alpine region，the comprehensive treatment method of unstable slope under this bad geology was put forward based on the unstable slope project of Zhangbei‒Shangyi Expressway.The governance protection structure consisted of a rigid protection system，drainage system，thermal insulation system，flexible protection system，and waterproof system.The rigid protection system was an anti-slide pile setting at the height of 1/3 of the first grade slope，of which parameters were calculated by cutting the slope of the rock layer in the unstable area to reduce the …

Treatment And Measurement Of Water Inrush During Highway Tunnel Construction, Wang C Haojie, Feng Zhihua, Fan Haobo

Journal of China & Foreign Highway

As a special geological condition of highway tunnels，water inrush will cause difficulties in engineering construction technology and management.Unnecessary disputes and management difficulties will emerge when different construction units hold different views about the treatment measures of water inrush，which leads to distributed provisions in the specification and a long treatment period.In view of key problems about the water inrush during highway tunnel construction，including water inrush treatment concept，investigation and estimation，measurement and pricing，and on-site confirmation，this paper systematically sorted out the current regulations and other guiding documents and investigated the treatment methods of tunnel water inrush and reverse slope pumping in China ’s highway …

Review Of Evaluation Methods For Mixing Workability Of Asphalt Mixture, Dong Fuqiang, Zu Yuanzhe, Yu Xin, Chen Bei, Liu Lin

Journal of China & Foreign Highway

To clarify the evaluation methods an d research status of mixing workability of asphalt mixture， by consulting relevant research literature in China and abroad and analyzing different evaluation methods，indexes，and research findings of the workability of asphalt mixture，the applicability and evaluation effects of different workability evaluation methods were systematically summarized，and the comparative analysis and comprehensive review were made on the main influencing factors of the mixing workability.The results show that in most evaluation methods for the mixing workability of asphalt mixture，corresponding indexes are constructed to quantitatively evaluate the workability by quantifying the resistance or energy consumption in the mixing process.Besides，in some …

Research Review Of Biomass Ash As Concrete Admixture, Ma Bicong, Liang Jian, Weng Yiling

Journal of China & Foreign Highway

In order to provide a comprehensive overview of research progress in the use of biomass ash as concrete admixture，the physical and chemical properties，mechanism of action，factors affecting the production process of biomass ash，and the effects of biomass ash incorporation on the working properties，mechanical properties，and durability of concrete were studied.The results show that biomass ash has a smaller density and a larger specific surface area than traditional mineral admixture，and the total amount of active components，namely SiO2 + Al2O3 + Fe2O3 （SAF） in most biomass ashes exceeds the requirements of class F volcanic ash （≥70%）.Incorporating biomass ash can effectively improve the mechanical properties …

Compaction Characteristics Of Granular Material And Its Structural Mechanical Behavior Considering Orthotropy, Huang You, Zhang Yunbao, Liu Zhaohui, Pan Yu, Liu Zebin, Fang Ronghai

Journal of China & Foreign Highway

The orthotropy of granular materials is closely related to the compaction process and has a significant impact on the mechanical behavior of pavement structures.In this study，in order to study the effect of the compaction process on the orthotropy of granular materials，different compaction methods and compaction energies were employed to compact granular materials for pavement into specimens，and improved dynamic resilient mechanical tests were conducted.Orthotropic coefficients （α2） of typical granular materials were obtained，and the finite element method was used to conduct mechanical analysis of asphalt pavement structures considering the orthotropy of granular materials.The results show that the dry density of specimens by …

Effect Of Basalt Fiber On Strength Of Cement‑Stabilized Macadam Base, Shu Hongbo, Tang Zhengguang, Zhang Yanhong, Bu Xilian, Liang Dong

Journal of China & Foreign Highway

To study the performance of basalt fiber in improving the poor angularity of the crushed cobble base，based on the orthogonal test，this paper determined that the optimal dosage of basalt fiber in the cement-stabilized crushed cobble was 1 kg/m3 （15 mm） + 2 kg/m3 （25 mm）.Besides，unconfined compressive strength and splitting strength tests were carried out on mixtures under three working conditions including the cement-stabilized crushed cobble，cement-stabilized crushed cobble with the optimal dosage of basalt fiber，and cement-stabilized macadam （limestone machine-crushed stone ）.The results show that influenced by the aggregate angularity，the strength of the cement-stabilized macadam （limestone machine-crushed stone ） mixture is better …

Design And Simulation Of Anti‑Collision System On Independent Pile With External Composite, Liao Yuanyuan, Liu Yu, Zhu Lu, Fang Hai, Zhang Jinrui, Han Juan

Journal of China & Foreign Highway

The precise calculation of the ship-bridge collision force is necessary for the assessment of the structural safety of the bridge and the design of an effective anti-collision system.Taking the ship-bridge issue in Furong Bridge in Xiangtan City，this paper compared the collision forces from different angles and in different locations calculated through the finite element software Ansys/LS-DYNA with the results calculated through the empirical formula，thereby determining the fortification collision forces of the bridge piers.Based on the weak anti-collision ability of the bridge double-limb thin-walled pier，the paper designed and implemented a new anti-collision system combined with composite and concrete-filled steel independent piles.The …