Civil and Environmental Engineering Commons^™

Research On Road Performance Of Carbonaceous Shale Subgrade Filler, Zhang Mengjin, Huang Yafei, Wu Qian, Mao Xuesong, Zhang Jianxun, Chen Xinyi, Wang Yueyue

Journal of China & Foreign Highway

The application of carbonaceous shale for subgrade filling not only alleviates the shortage of subgrade filler in carbonaceous shale distribution areas but also meets the strategic requirements of “resource conservation and saving ” and “green development ” for infrastructure construction in China.However，such rocks are weak and susceptible to weathering and disintegration，and they exhibit significant strength deterioration when exposed to water.To fully apply them，their performance must be comprehensively understood.In this paper，the basic properties of the carbonaceous shale were studied，and filler gradation was designed.The tests on compaction characteristics of the filler and particle crushing characteristics after compaction，RCBR （California bearing ratio ） variation …

Mesoscopic Numerical Simulation Of Concrete Cracking Caused By Nonuniform Corrosion Of Strands, Zeng Tianbao, Chen Hong, Huang Xiaoqi, Tu Ronghui, Dai Lizhao

Journal of China & Foreign Highway

The non-uniform corrosion of spinning strands will induce concrete cracking.A non-uniform expansion model of corrosion products of strands was established，and a mesoscopic numerical model of concrete cracking caused by non-uniform corrosion of strands was built.Concrete was considered as a three-phase composite material composed of mortar matrix，aggregate，and interface layer.The concrete cracking behavior caused by the non-uniform corrosion of strands was simulated by embedding cohesive elements.The rationality of the proposed model was verified by existing experimental data，and the influence of protective layer thickness and aggregate content of concrete on the width of corrosion-induced cracks was discussed.The results show that the proposed non-uniform …

Research And Field Test On Ultra‑Thin Wearing Course Based On Balanced Design Concept, Gu Jianjun, Li Xia, Li Atan, Sun Qiang, Li Jie, Jiang Zhaowei

Journal of China & Foreign Highway

To address the application of an ultra-thin wearing course in expressway asphalt pavement maintenance engineering，the ultra-thin wearing course system based on the balance design concept was systematically studied.In this paper，the action mechanism and application characteristics of modifiers were analyzed，and the proportion design test of the ultra-thin wearing course was designed based on the balance design method.Finally，according to the proportion design test，the optimal proportion of the ultra-thin wearing course material was selected for test road paving.Research shows that the direct-cast high viscosity modifier is convenient for transportation and storage，improves the elastic recovery of asphalt mixtures and reduces permanent deformation.Under the condition …

Experimental Study On Static And Dynamic Mechanical Properties Of Pva Fiber‑Reinforced Coral Concrete, Zhou Jinyi, Long Zhilin, Guo Ruiqi, Kuang Dumin, Cai Yang, Chen Shasha, Chen Jinjie

Journal of China & Foreign Highway

To enhance the mechanical properties of coral concrete，static mechanical tests were conducted at five polyvinyl alcohol fiber volume fractions （0，0.5%，1%，1.5% and 2%）.The impact compression properties were investigated under four strain rates using a split Hopkinson pressure bar with a diameter of 100 mm.The results show that the incorporation of an appropriate number of fibers can significantly improve the static compressive strength and splitting tensile strength of concrete.Dynamic mechanical tests show that coral concrete has an obvious strain rate effect，and the incorporation of fibers can improve the sensitivity of the dynamic reinforcement factor to strain rate，with the reinforcement effect becoming saturated …

Influence Of Warm‑Mixed Flame Retardant Technology On Construction Environment Of Asphalt Pavement In Long Tunnel, Xian Jianglin, Li Yanxiang, Yang Qingyang

Journal of China & Foreign Highway

With the long tunnel as the research object，the variation of volatile organic compound （VOC） volume fraction，CO volume fraction，and illuminance in the construction area of the middle of the tunnel under the conditions of hot mix technology and warm-mixed flame retardant technology was tested respectively，and the influence of warm-mixed flame retardant technology on the construction environment of asphalt pavement in long tunnels was analyzed and evaluated.The results show that when the pavement of a long tunnel adopts hot mix technology，the mass concentration of asphalt fume in the whole operation area is relatively high，and that in some areas exceeds the threshold value.The …

Influence Of Concrete Barrier Slope Parameters On Protective Effect Against Vehicle Collision, Gong Shuai

Journal of China & Foreign Highway

In order to study the influence of concrete barrier slope parameters on the protective effect against vehicle collision，the vehicle models and concrete barrier models were established.The validity of these models was verified using the real vehicle test data.Then，the collision analysis was conducted on the single-slope concrete barrier with different slopes，improved concrete barrier with different slope parameter combinations，and reinforced concrete barrier with anti-climbing function by using the validated models，respectively.The results show that the slope is the key parameter that affects the protective performance of the single-slope barrier，and vehicles cannot be effectively protected if the slope is too small or too large.The …

Ammonia Recovery From Digester Centrate With Electrochemical Membrane Systems: Mechanism, Performance, And Application, Fubin Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Nitrogen plays an indispensable role in living organisms and thus is a key element for agricultural production. Ammonia (NH3), as an important part in nitrogen cycle, can be synthesized by nitrogen fixing bacteria and the Haber-Bosch process, the latter of which requires an extensive energy input. Wastewaters can contain a large amount of nitrogen compounds because of kitchen and toilet wastes being discharged to sewage. The concentration of ammonia nitrogen (NH4+-N) can be hundreds mg per liter in some wastewaters like anaerobic digester (AD) centrate. However, both Haber-Bosch process and conventional wastewater ammonia treatment process are energy intensive, which making …

Studying The Production Of Nanocelluloses, Shohzodbek Abduvahobovich Rashidov, Elmurod Abduqodirovich Egamberdiev, Sadritdin Maxamatdinovich Turabdjanov

Technical science and innovation

Nanoscience is a broad field that includes nanophysics and nanochemistry. Nanotechnologies are aimed at obtaining nanoparticles with new properties and creating materials and devices based on them. This is one of the modern trends in the development of science in the 21st century.

Based on the study of information about nano-sized materials, the mechanisms of their production and changes in their properties, we will consider the technology for producing nanocellulose from organic substances, i.e. from cellulose. The article describes a technology that examines devices for producing nanocellulose and the principles of their operation, as well as a combined method of …

Evaluation Of Long‑Term Water Stability Of Acidic Diorite Asphalt Mixtures In Different Environments, Cao Zhonglu, Chen Ping, Liu Xuewen, Tan Bo

Journal of China & Foreign Highway

The short-term water stability of acidic diorite asphalt mixtures with acid-alkaline composite aggregates mixed with cement （2% cement instead of mineral powder ），slaked lime （30% slaked lime water for stone immersion ），and anti-spalling agent （modified asphalt with 0.3% anti-spalling agent ） was evaluated by Marshall test of immersion，freeze-thaw splitting test，and rutting test.Then，by repeated freeze-thaw splitting test，repeated freeze-thaw and baking splitting test，and repeated acid-etching freeze-thaw splitting test，the long-term water stability of the treated acidic diorite asphalt mixtures in different environments was tested.The results show that the physical and mechanical properties of acidic diorite meet the specification requirements；the short-term water stability of …

Test And Analysis On Stress And Deformation Of Assembled Geocell Retaining Wall, Kong Yongbo, Li Hao, Zhang Jianwei, Li Junjie, Yang Xiaohua

Journal of China & Foreign Highway

The variable cross-section geocell retaining wall of the Chengdu –Yibin Expressway test road in Sichuan Province of China was studied.First，the construction method of the new-type assembled geocell retaining wall was introduced，and the new-type glass fiber reinforced plastic lightweight panel was used to effectively solve the problem that the panel of the retaining wall is not neat and easy to be damaged.Secondly，the supporting effect of the retaining wall was analyzed by field monitoring.The field monitoring results show that the earth pressure at different parts of the retaining wall is nonlinearly distributed along the height of the retaining wall.The earth pressure at …

Reasearch On Fatigue Failure Law In Tension‑Shear Zone Behind Wheel In Rigid And Flexible Composite Pavement, Cheng Xiaoliang, Deng Fuhao, Wang Yang, Han Leilei, Zhou Wujun

Journal of China & Foreign Highway

In order to study the slippage mechanism of asphalt concrete overlay on continuous reinforced concrete composite pavement （CRCP），the structure of the composite pavement was modeled using the elastic layered system，and the interlayer bonding state of the model was calibrated by the measured data of the road.In the analysis of interlayer mechanical behavior，it was found that when the horizontal force coefficient was 1，there existed a tension-shear zone behind the wheel，which may lead to the failure of this zone prior to the position of the maximum interlayer shear stress.Relevant test data analysis shows that when the horizontal force coefficient is 1，under the …

Experimental Research On Anti-Uv Aging Performance Of Tire Pyrolysis Carbon Black （Tpcb） Modified Asphalt, Yang Wansheng, Yi Shuaibing, Dai Tianle, Li Tiantian, Gan Youwei

Journal of China & Foreign Highway

To investigate the anti-ultraviolet （UV） aging performance of waste tire pyrolysis carbon black （TPCB）-modified asphalt，TPCB-modified asphalt was prepared and subjected to UV aging tests alongside the base asphalt at various intervals.The micro changes and surface roughness of two kinds of asphalt surfaces were studied by atomic force microscopy （AFM）.The behavior changes in ductility，softening point，and penetration of two asphalts before and after UV aging were tested by asphalt performance tests.The results show that the reduction height of TPCB-modified asphalt is smaller than that of base asphalt，and the surface roughness is larger than that of base asphalt at each time.The performance change …

Structure And Material Of Rigid‑Flexible Composite Pavements And Development, Liu Zhaohui, Huang You, Yu Shiqing, Liu Jingyu, Li Sheng, Liu Li, Pan Yu

Journal of China & Foreign Highway

The rigid-flexible composite pavement，as a kind of durable pavement structure，has been widely used for heavy-duty traffic，special geological conditions，bridge tunnel paving，etc.In order to promote the application of durable rigid-flexible composite pavements and clarify the key research issues and development directions，relevant research progress of rigid-flexible composite pavements in China and abroad was reviewed.Based on the structure design theory and construction technology of rigid-flexible composite pavements，the structural mechanical behavior characteristics of rigid-flexible composite pavements were described，and the stress induced by load and temperature of asphalt surface layer and rigid base layer，as well as their interactions were analyzed.The asphalt surface layer on the rigid …

Experimental Study On Double‑Mixture Solidification And Ratio Optimization Of Dredger Fill Sludge, Qin Liang, Chen Zhimin, Lu Yongfei

Journal of China & Foreign Highway

In order to study the optimal r atio of cement and calcium oxide by double-mixture solidification for improving dredger fill sludge，the soil modification results by double-mixture solidification were analyzed based on orthogonal experiments.Finally，the fuzzy comprehensive evaluation method was used to quantitatively optimize each ratio scheme.The results show that：① Under the same addition ratio （addition amount of 1.0%‒4.0%），there is a positive linear correlation between the optimal moisture content and the addition amount，and there is a negative linear correlation between the optimal moisture content and the maximum dry de nsity.Under non-equal addition ratios，the law is not obvious.However，compared to cement，the water-reducing effect of …

Road Performance Of Reclaimed Asphalt Mixture Mixed With Bagasse Fibers And Rubber‑Modified Asphalt, Jiang Xin

Journal of China & Foreign Highway

Given the potential resource value of rec laimed asphalt pavement，waste rubber powder，and bagasse fibers，it is meaningful to develop the cooperative utilization of various solid wastes.This paper studied the microstructure and thermal characteristics of bagasse fibers，carried out the mix design of a reclaimed asphalt mixture with bagasse fibers and rubber-modified asphalt，and evaluated its road performance.At the same time，the test road was paved successfully and observed for a time.The results show that the hollow lumen with multilayer fiber structure in bagasse fibers contributes to absorbing free asphalt in mixtures and enhances the adhesion between bagasse fibers and asphalt.The thermal properties of bagasse …

Feasibility Of Sandstone Used In Asphalt Pavement Of Expressways, Lou Jianmin, Meng Xiandong, Song Zhike, Zhao Lidong, Bai Julong, Zhao Shengli, Zhu Jishuang

Journal of China & Foreign Highway

In order to explore the feasibility of applying sandstone in the asphalt pavement of expressways，the physical and mechanical indexes of sandstone and limestone aggregate were compared，and the high temperature performance，low temperature performance，and water stability of asphalt mixture were studied from the aspects of grading type，asphalt type，and aggregate lithology.The results show that the road performance of asphalt mixture synthesized by clean and regular sandstone aggregate meets the requirements of current specifications.At the same time，the comprehensive road performance of sandstone asphalt mixture with 1% anti-stripping agent has been improved.

Key Construction Techniques For Emended Cap Unsealed Bottom Of Deep‑Water Hard Rock, Zeng Jian, Guan Xiaohui, Guo Zhiwei

Journal of China & Foreign Highway

In the construction of a deep-water embedded cap foundation，it was required to excavate the mud surface to the depth below sealing concrete and clean the bottom carefully，ensuring the height and quality of bottoming concrete.For hard rock under good geological conditions，there exist such problems as difficulty in excavation，long excavation time consumption，and high construction cost.Based on the construction of the main pier caps of the Chongqing Jiahua Metro Bridge，this paper adopted the method of combining theoretical analysis，numerical calculation，and engineering implementation verification，which developed an emended cap unsealed bottom key construction techniques for deep-water hard rock.This construction technology used the method of excavating the …

Influence Of Blasting Point Position And Foundation Pit Height On Blasting Vibration During Foundation Pit Blasting Excavation, Liu Kuan, Xu Zhihao, Tang Yuan, Shen Jun, Bao Xiaohua, Shen Pinghuan, Ou Yang

Journal of China & Foreign Highway

In view of inaccurate vibration prediction of foundation pit blasting，the influence of blasting point position and foundation pit height on vibration during foundation pit blasting excavation was studied by using finite element simulation software.First，based on the foundation pit blasting excavation of the Mawan Cross-Sea Passage，a numerical simulation was carried out to verify the applicability of the model.Then，under unchanged blasting center distance，the distance from the blasting point to the edge of the foundation pit and the foundation pit height were changed respectively，and the influence of these two factors on surface vibration was studied.The results show that a greater distance from the …

Excavation Method For Ⅴⅴ‑Grade Surrounding Rock Of Double‑Hole Eight‑Lane Super‑Long‑Span Tunnel, Shi Youzhi, Liu Xudong, Yong Jinzhu

Journal of China & Foreign Highway

In order to reduce the adverse effect of back heading blasting on the completed supporting structure at the entrance of a double-hole eight-lane super-long-span tunnel with Ⅴ-grade surrounding rock，the Niuzhaishan tunnel project in Pingtan was taken as an example.The original design of the double-side heading method is easy to cause the collapse of the temporary steel support that has been completed when blasting happens near the back heading.In view of this，this paper put forward scheme 1 of canceling the temporary transverse support and the up-and-down step method with vertical support （scheme 2）.It then used the finite element method to calculate …

Design And Evaluation Of Land‑Saving And Beautiful Median Barriers, Li Jingjun, Wa Ng Xin, Qi Jie, Wang Zijian, Liu Siyuan

Journal of China & Foreign Highway

During the construction and expansion of expressways and national and provincial highways，more diversified requirements have been put forward for the median barrier，including reliable protective performance，small footprints，beautiful traffic environments，and economic costs.However，the existing median barrier achievements still have some shortcomings.In order to better meet the design and use needs of median barriers for highways，theoretical analysis，computer simulation，and full-scale impact tests with real vehicles were adopted，and the force characteristics of different types of median barriers were analyzed.A new design concept of beam-column integration was put forward.Through systematic research on the barrier height，width，beam，column，foundation，and other structures，a land-saving and beautiful median barrier was developed.The median barrier had …

Multi-Region Plane Fitting Algorithm For Texture Depth Of Asphalt Pavements, Zhu Feng, Feng Xingle, Wu Chuan, Lin Xiaoyong

Journal of China & Foreign Highway

The existing calculation methods for texture depth of asphalt pavements are easily affected by external and human factors.Therefore，a multi-region plane fitting algorithm for the texture depth based on three-dimensional （3D） linear laser data was proposed.The algorithm preprocessed the collected 3D height data matrix of the pavement and derived a slope-based adaptive filtering algorithm for point cloud data.Then, the 3D height matrix was divided into multiple regions，and the local extremum of the center point was determined.Finally，with the three-point and one-surface plane fitting algorithm as the core，the texture depth of asphalt pavements was calculated.The experimental results show that the correlation between this …

Key Technology And Numerical Simulation Of Cast‑In‑Place Construction Of Main Arch Ring Of Reinforced Concrete Arch Bridge Based On Suspension Steel Arch Method, Su Xueping, Xia Zhengzhi, Lyu Songgang, Duan Pengjie, Lyu Yigang

Journal of China & Foreign Highway

Steel arch frame replaced such construction methods as floor bracket or segment cantilever assembly and it was applied to arch circle cast-in-place across deep water canyons in mountainous areas，which had certain advantages and was worth promoting and applying.By introducing the key construction technologies of Sanchahe Bridge，including steel arch frame cantilever fastener method assembly，arch water tank method precompression，and main arch ring layered pouring，the common problems in the construction process of crossing the deep water canyon were solved effectively.Based on Midas Civil overall modeling of finite elements，the key construction technologies adopted by the bridge were numerically simulated and analyzed，and the successful construction …

Guardrail Improvement For Old Bridges In Expressways, Liu Xinping, Zhang Shihui, Shang Zhongping, Han Yue, Zhang Qiang

Journal of China & Foreign Highway

In view of the insufficient protection grade of the guardrail in old bridges，a combined guardrail suitable for the low concrete wall guardrail in the old bridge was designed and developed by using finite element analysis while not damaging the main structure of the bridge.The protection grade was verified to reach SA grade through a full-scale vehicle collision test.The guardrail was designed with new high-strength alloy steel，with light weight and beautiful appearance.There was no need to dismantle the original concrete foundation in the old bridge，which is convenient for construction and requires low cost.Therefore，it is worth being popularized and applied in the …

Improvement Of Gravelly Laterite And Cement Stable Disposal In West Africa, Jin Haibing, Yi Zicheng, Zhuo Rong

Journal of China & Foreign Highway

Owing to poor gradation and high liquid limit and plasticity index，the application of gravel laterite on road paving is limited in West Africa.To overcome this issue，laterite granule combined with sand at different content was explored.The performance including the particle composition，limit water content and CBR value was investigated.The results indicate that sand treatment can improve the gradation，enhance the compactness，and reduce the plasticity index.The improved gravel laterite can meet the requirements of subbase，cushion，and base courses.Cement treatment can improve the mechanical properties of laterite grains.Cement and sand content affect the unconfined compressive strength significantly，with an optimal sand content range identified.Specifically，laterite granules mixed with …

Water Banking As A Strategy For The Management And Conservation Of A Critical Resource: A Case Study From Tunisia's Medjerda River Basin (Mrb), Aymen Sawassi, Roula Khadra, Brian Crookston

Civil and Environmental Engineering Faculty Publications

The increasingly adverse impacts of climate change (e.g., rainfall patterns, droughts, and floods), coupled with the ever-increasing water demands, are often translated into a contingent liability for water users' communities. Additional complexities arise due to competing priorities, water rights, and transboundary water sources. Therefore, conventional water management practices should shift toward more comprehensive and responsive integrative approaches, even for systems with limited data. Furthermore, water managers must prioritize dynamic and interactive management techniques for existing systems. One such management technique is water banking, which is the focus of this study. Herein, a dynamic interactive water allocation model, which encompasses the …

Environmental Drivers Impact The Accumulation And Diversity Of Antibiotic Resistance In Green Stormwater Infrastructure, Kassidy N. O'Malley, Patrick J. Mcnamara, Christopher Marshall, Emily Lou Lamartina, Thuy Duyen Lam, Numair Ali, Walter M. Mcdonald

Civil and Environmental Engineering Faculty Research and Publications

Antibiotic resistance poses an urgent public health concern, with the environment playing a crucial role in the development and dissemination of resistant bacteria. There is a growing body of research indicating that stormwater is a significant source and transport vector of resistance elements. This research sought to characterize the role of green stormwater infrastructure (GSI), designed for stormwater infiltration, in accumulating and propagating antibiotic resistance in the urban water cycle. Sampling included 24 full-scale GSI systems representing three distinct types of GSI - bioswales, bioretention cells, and constructed wetlands. The results indicated that GSI soils accumulate antibiotic resistance genes (ARGs) …

Investigating The Impact Of Secondary Activation Time On The Adsorption Properties Of Activated Biochar For Arsenic Removal From Wastewater, Achyuth Bharadwaj Rayarao

Graduate Theses and Dissertations (2019 - present)

Biochar, a naturally occurring and renewable carbon material, becomes porous through activation. Activated biochar is an ideal candidate for use as an adsorbent. The objective of this study is to investigate whether activated biochar derived from Colorado soft pine serves as a better adsorbent and demonstrates enhanced adsorption capabilities after undergoing secondary physical activation at various activation times. The effect of secondary action time on physical adsorption properties drawn from the analysis of isotherm plots, surface areas and pore size patterns were examined by using a physisorption analyzer. Chemical structures were identified using both ultimate and proximate analyses, while porosity …

Creating A Bio-Based Circular Economy From Louisiana Sugarcane Byproducts, G. Aita, D. Bhatnagar, G. O. Bruni, M. Deliberto, G. Eggleston, A. Finger, K. Gravois, M. Isied, W. Judice, K. T. Kasson, I. M. Lima, J. L. Purswell, Mena I. Souliman, E. Terrell, B. S. Tubana, H. L. Waguespack Jr., J. J. Wang, P. M. White Jr.

Civil Engineering Faculty Publications and Presentations

Sugarcane (Saccharum officinarum) is Louisiana's number one row crop. Growing and processing sugarcane produces significant amounts of byproducts, including bagasse, crop residue, molasses, filter-press mud, and boiler fly ash. These products represent an important opportunity to generate value-added and specialty products and enhance sugarcane's sustainability by facilitating a circular economy, where agricultural by-products are reused instead of disposing them (linear economy), in order to reduce resource use and energy demand. Examples of value-added products range from biochar, construction materials, animal feed, biofuels, nanoparticles, and fertilizer. Paramount to the success of the bio-based circular economy is creating useful products that are …

Comparative Analysis Of Cutting Forces In Axial-Compliant And Rigid Chamfering Tools, Sultonmurod Bekpulatovich Normatov, Oybek Tuyboyov, Azimjon Axror O'G'Li Pardayev, Alisher G‘Ayratjon Ogli Boratov, Shohjahon Tuxtasin Ogli Abdullayev

Technical science and innovation

This study delves into the analysis of cutting forces in axial-compliant systems, focusing specifically on the comparison between axially spring-compensated 90° conical tools and rigid chamfering tools. The research incorporates a predictive model for chamfer size calculation in the axially spring-compensated tools, verified through experimental tests on representative parts. The study aims to control chamfer size within tolerances by adjusting process conditions and optimizing processing efficiency. By exploring the fundamentals of the chamfering process, this research offers insights into breaking sharp edges on components with positional errors and shape deformations, with a particular emphasis on aero-engine casings. The integration of …

Identification Of Compounds That Cause Axonal Dieback Without Cytotoxicity In Dorsal Root Ganglia Explants And Intervertebral Disc Cells With Potential To Treat Pain Via Denervation, Fei San Lee, Uyen N. Nguyen, Eliza J. Munns, Rebecca A. Wachs

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Low back pain, knee osteoarthritis, and cancer patients suffer from chronic pain. Aberrant nerve growth into intervertebral disc, knee, and tumors, are common pathologies that lead to these chronic pain conditions. Axonal dieback induced by capsaicin (Caps) denervation has been FDA-approved to treat painful neuropathies and knee osteoarthritis but with shortterm efficacy and discomfort. Herein, we propose to evaluate pyridoxine (Pyr), vincristine sulfate (Vcr) and ionomycin (Imy) as axonal dieback compounds for denervation with potential to alleviate pain. Previous literature suggests Pyr, Vcr, and Imy can cause undesired axonal degeneration, but no previous work has evaluated axonal dieback and cytotoxicity …