Repair Projects Research Articles

The REPAIR Project, a Deep-Underground Radiobiology Experiment Investigating the Biological Effects of Natural Background Radiation: The First 6 Years.

In 2017, a special edition of Radiation Research was published [Oct; Vol. 188 4.2 (https://bioone.org/journals/radiation-research/volume-188/issue-4.2)] which focused on a recently established radiobiology project within SNOLAB, a unique deep-underground research facility. This special edition included original articles, reviews and commentaries relevant to the research goals of this new project which was titled Researching the Effects of the Presence and Absence of Ionizing Radiation (REPAIR). These research goals were founded in understanding the biological effects of terrestrial and cosmic natural background radiation (NBR). Since 2017, REPAIR has evolved into a sub-NBR radiobiology research program which investigates these effects using multiple model systems and various biological endpoints. This paper summarizes the evolution of the REPAIR project over the first 6-years including its experimental scope and capabilities as well as research accomplishments.

Approach for Estimating Inspection Staffing Needs for Highway Construction Projects

Construction inspectors are the primary workforce in the highway construction industry who ensure that the work on infrastructure projects meets or exceeds the quality standards set. However, there is a growing concern in state departments of transportation (DOTs) about the inspection process because of the declining availability of experienced inspectors. This study proposes an approach for estimating inspection staffing needs for highway construction projects. Data from 157 construction projects completed between 2017 and 2021 were used to evaluate project inspection staff size based on the project type, cost, and duration. A total of 35 core inspection items were identified by carrying out a content analysis of construction inspection documents. Then, a focus group of 18 experts from the Kansas DOT was conducted to verify the list of 35 cost inspection items and evaluate the number and experience of inspectors required for each item. The four project types included in the analysis are as follows: grading/surfacing; sealing; surface recycling and overlay; and bridge repair. The analysis showed that the inspection staffing needs depend on project type, duration, and size. The grading/surfacing and bridge repair projects require more inspection staff than the sealing, and surface recycling and overlay projects. The result of a Spearman’s correlation analysis indicated that there is a significant association between the risk level of an inspection item and the number and experience of inspectors required for that item. The findings from this study may help state DOTs identify their needs for inspection staff and improve the quality of highway construction projects.

Efectiveness Comparison of Overtime Hours with Technical and Economical Employment on 10165 Ton Gwt Tanker Ship Repairation

Aspects of ship repair planning must be considered, especially during the ship repair process. This component is closely related to what is needed by professionals in specific fields. Project completion time can also be estimated using the number of workers involved in the production process. The salary paid by the company also correlates with the number of employees. One of the techniques to speed up work on a tanker repair project by increasing working hours which is often referred to as overtime hours with two approaches to speeding up work on a project evaluated technically and economically compared by researchers. Researchers evaluate project work and calculate the workforce involved in tanker repair. Researchers perform calculations for each part of the workforce in the ship repairment process, and also analyze the scheduling of each part of the workers that have been prepared by the company. Working on the project experienced a shortage of manpower and more often used the overtime system. and it can be seen from the results of the study that adding labor is more efficient from an economic point of view because the costs incurred are less and the processing time does not exceed the specified duration.
 
 Keywords: Tanker Ships; Labor; Duration; Cost

A Study on the Improvement Task of the Old Low-Rise Residential House Repair Project through the Urban Regeneration Project

Among the detailed projects of urban regeneration projects, the house repair project is the most responsive to residents. Therefore, the purpose of this study is to derive improvement measures for housing repair public support projects in old low-rise residential areas when promoting urban regeneration projects in declining areas and to present implications. Until now, public support for housing repair has been providing housing repair benefits to low-income families, but detailed guidelines were ambiguous because it was the first project, and the connection was not smooth due to the discovery and development of local housing repair operators. The purpose of this study is to systematically examine the improvements of the current urban regeneration housing repair public support project through expert interviews by group by dividing it into housing repair guidelines, intermediate support organizations, and sustainable business models. Through this study analysis, improvements such as diversification of budget execution methods and expansion of support scope, operation of business information and registration system, provision of standard quality standards, and enhancement of residents’ participation through connection with street maintenance were derived.

Utilizing Underwater FRP System for Hydraulic Structures Application

The development of the use of advance composites is remarkable, especially in applications that require the materials used to be corrosion resistant. One of the most important of these applications is the structures built inside or under water, especially hydraulic structures. Constant exposure to wet makes materials such as concrete and steel threatened to the high level of corrosion and deterioration. The traditional methods for repairing proved insufficient over time, in addition to being expensive in some cases. Therefore, it became necessary to search for alternatives that achieve engineering efficiency and lower costs. One of these alternatives is the use of fiber reinforced polymer (FRP) system. Until recent years, it was not possible to use FRP system under water as a repair system for hydraulic structures without cofferdam. However, during this period, types of underwater cured resins were produced and underwater FRP system is the best choice for this type of structures. There are no many practical applications for the use of FRP in repairing of hydraulic structures, so it is possible to study its application in marine structure to show the possibility of use it in hydraulic structure. This research highlight the advantages and disadvantages of traditional method in repairing underwater structures. Also present project that considered the underwater FRP as a construction material used in the rehabilitation of deteriorated concrete pile. As a conclusion, using fibers with water activated resin can provide an economical solution for future repair and rehabilitation projects. Also the pre-preg system is efficient for repairing dry zones, while the wet layup system is very effective in repairing splash zones of damaged structural elements.

Comparative Analysis of CPM, PDM and PERT Methods in Ship Repair Scheduling Planning KN. RB 309 Ternate 01

A ship that is still carrying out sailing activities must always be in a state that is in accordance with the classification and statutory. Maintenance or repair is needed for the ship in order to stay in good condition and fit to sail. In a ship repair project, there are several important aspects that need to be considered in order to complete project activities quickly and precisely. PT. XYZ has carried out ship repair activities, but the repair activities have been delayed due to weather factors, and the late procurement of spare parts. This research was conducted by analyzing the three models of scheduling fiberglass ship repair projects using Microsoft excel and using the CPM (Critical Path Method), PDM (Precedence Diagram Method) and PERT (Project Evaluation and Review Technique) methods. Results from the CPM method on 48-day A scheduling, 33-day B scheduling, and 21-day C scheduling. Pdm method results scheduling A 48 days, scheduling B 33 days, and scheduling C 21 days. In the PERT method the project can be completed in 48 days which is 48.67%, scheduling B 34 days 5 hours 21 minutes with the possibility of a KN ship repair project. RB 309 Ternate 01 can be completed in 48 days i.e. 99.35% and scheduling C 22 days 5 hours 21 minutes with the possibility of a KN ship repair project. RB 309 Ternate 01 can be completed in 48 days which is 99.99%.

ОЦІНЮВАННЯ ВПЛИВУ НА ДОВКІЛЛЯ ПРИ БУДІВНИЦТВІ ТА РЕКОНСТРУКЦІЇ АВТОМОБІЛЬНИХ ДОРІГ

Introduction. Environmental impact assessment is an important legal instrument that is aimed at preventing / minimizing environmental damage, ensuring environmental safety, rational use of natural resources, in the decision-making process on the implementation of economic activities. EIA is an important legal tool to prevent the consequences of activities of both enterprises and planned activities. This tool is as close as possible to European Union standards. EIA is carried out in compliance with the requirements of the legislation on environmental protection, taking into account the existing ecological state, environmental risks of the planned activity, prospects for socio-economic development, the power of the combined direct and indirect impact, including taking into account existing facilities. An EIA is a procedure preceding a planned economic activity (in this case, the construction or reconstruction of roads) and involves determining the nature, degree of danger of this activity on the environment and public health Problem Statement. Projects for the construction and reconstruction of roads are an integral part of Ukraine. Transport infrastructure has a significant negative impact on the environment, which is accompanied by the transformation of ecosystems, fragmentation of landscapes. In addition, motor vehicles are a powerful source of pollution of the atmosphere, territories and water areas adjacent to roads, and noise pollution. However, do not ignore the economic importance of road communication. That is why, the planning, construction and operation of roads must be carried out in accordance with environmental standards, and the norms themselves must ensure minimization of environmental impact. So far, there are no clear practical recommendatory criteria for determining the environmental damage of the proposed activity and the preparation of the EIA report. That is why it is important to constantly improve existing methods and definitions of environmental risks in order to form an assessment mechanism. This study is devoted to the application of one of such modern mechanisms of environmental impact assessment. The use of the method for assessing the level of environmental hazards for the implementation of the planned activities in the construction and reconstruction of critical infrastructure facilities was tested. Purpose. To test the method of assessing the level of environmental impact in the implementation of planned activities in the construction and reconstruction of the highway. Research methods. general scientific (generalization, comparison, analysis and synthesis, theoretical and methodological substantiation); mathematical statistics Results. To quantify the interaction between the types of activities (or groups of acting factors) during the project and the components (environmental characteristics) of the environment, a combined approach was taken to assess the impact using the improved Leopold matrix. The matrix is a table that contains horizontally a list of processes that affect the environment during the reconstruction (repair) of the road, vertically — criteria and indicators of impact, as environmental characteristics. The evaluator (analyst, project developer, expert) can modify the matrix in accordance with the specific tasks of the road construction and reconstruction (repair) project. Conclusion. The generalized function allows you to set an integral indicator of environmental impact assessment, which is a quantitative, unambiguous, universal indicator of the quality of the studied object and can be used as an EIA criterion for the construction and reconstruction (repair) of a road through its adequacy, efficiency and statistical sensitivity.

Efforts and Barriers Shifting a City Region Towards Circular Transition – Lessons from a Living Lab from Pécs, Hungary

A Circular Economy is usually seen as achieving ‘zero waste’ and closing the material flow loops. However, multiple governance, economic, legal, socio-spatial, cultural, and behavioural barriers may easily hamper the transition. This study summarises the lessons learned from the waste flow analysis and living lab (LL) of a case study from the H2020 REPAiR project. It shows how the results of a waste flow analysis created for an urban area can help decision-makers to co-create new place-based eco-innovative solutions and hence shift the city towards circularity. At the same time, during the living lab process, it became clear that the decision support method alone is not enough to co-create or co-design new innovations, in addition the regulatory environment and the peculiarities of governance may also present multiple obstacles. The centralised governance in Hungary and the centralisation tendency in waste management and secondary resource use hamper efficient local resource management. The work in the LL showed that a centralised governance structure hinders not only the co-creation of new solutions but also the transfer of good practices from other peri-urban areas. This is important because a society that is generally less innovative and less developed at the beginning of sustainability transition is innovating for the first time via the transfer of eco-innovative solutions. Our paper shows that the governance structure of a given spatial unit (i.e. a city region) may be a significant factor in the successful or unsuccessful adoption of good practices and for the circular transition, as may system adaptability, the level of local technological development, the level of integration of actors, strategies, interests, and policy interventions.

Stochastic Failure Mode Effect And Critical Analysis (SFMCEA) on Repair and Retrofitting Projects

FMEA is a known method in risk management that de-fines the failure that might happen and identifies its hazards on the system; this procedure can be done using the risk priority number “RPN” analysis system. This method is applied on a real repair project “Sheraton Hotel” located in Cairo city near the Nile River where they had to make urgent repairs to avoid failure and collapse of the building. This study concentrated on developing the results and most common failures that might happen in any emergency project by determining the severity, occurrences, and detection to get the overall RPN of each failure. Two methods were used to rank the risks, the first one is the traditional approach which is based on getting one value for the severity, occurrence, and detection. On the other hand, the other method is getting a range of values (3 values) for the severity occurrence, and detection. The results showed that using the traditional form of RPN resulted in three major risks such as ineffective work penalties, complex contractor’s policies, and risks related to contract agreement. On the other hand, the use of a probabilistic analysis showed that the top risks are ineffective work penalties, problems with contract agreement, and unfavorable contract.

Study of the Structural Mechanical Properties of Drainage Canals Rehabilitated by Spraying Method.

A large number of drainage pipes and canals in China have been in disrepair for a long time and there have been problems such as leakage and corrosion. In response to these problems, this paper studies a non-excavation technology for repairing the arched canal structure—the in-situ spraying method. To study the influence of the original canal structure on the mechanical characteristics of the lining structure by in-situ spraying and the restraint effect on the lining structure, a field model test with a similar ratio of 1:2 was conducted in the field test pit. By conducting four stages of three-point concentrated load loading tests, the mechanical characteristics of the lining structure were investigated to reveal the influence of the canal structure on the force of the lining structure. The test results show that: the maximum crack width of the newly added lining structure is 0.27 mm and the normal service ultimate bearing capacity of the arched structure repaired by H-70 reaches 150 kN; comparing the loading test and the numerical simulation results, the difference between the two vault displacement results is 4.65% and the results are relatively consistent. The displacement of the bottom of the lining structure is small and the participation of the bottom plate is small, while the displacement of the upper arch structure of the lining is significantly larger than the lateral displacement, indicating that the canal structure can effectively limit the lateral displacement of the newly added lining and that the canal structure is greatly reduced. The bending moment of the lining structure is improved and the restraint effect on the arch foot is more obvious. This paper proposes the use of H-70 to repair arched canal structures by the in-situ spraying method and seeks to prove the feasibility of this method and fill the gap of research in this area. This paper provides the structural design basis and experimental knowledge for the construction of the repair method, which has important practical significance for the pipeline repair project in the future.

Impacts of road and hydrographic networks in the conditions of the Raut river basin environment

Road infrastructure in the Republic of Moldova represents the totality of road networks classified in express, republican and regional, including a complex of objects that ensure the efficiency of road traffic, such as bridges, gas stations, pedestrian crossings, street lighting, etc. Road construction and maintenance also require changes in geographical systems, including within river basins. The research highlights the impact of the river network on road infrastructure construction and maintenance projects and at the same time the impact of the road network on the river network in the environmental conditions within the Răut river basin. Therefore, the most frequent environmental impressions are left by the relief levelling and geological settlement works, by the extraction and displacement of mineral substances (gravel, sand) according to construction or repair projects, river valley modelling for bridge construction, landscaping of the space adjacent to the roads by deforestation of trees, irradiation of the soil layer, by modification of surface runoff and environmental pollution.

On-Site Risk Assessment Methodology of Historic Timber Structures: The Case Study of Santa Cruz Church

The conservation and repair of historic structures require significant resources. Therefore, it is important to conduct a complete assessment of the object. Specifically, historical timber frame structures are very common in the Spanish and Andalusian geographic area. This research proposes and develops a simplified approach to facilitate decision making when faced with this complex work. By the application of long-established non-destructive tests, such as organoleptic and measuring inspection, resistography, and electric moisture content test, combined with visual classification parameters, these data were used as boundary conditions into a simplified structural calculation method. This process, which is simpler than other calculation systems, allows compiling important information about the safety level of the structure and its critical points. Finally, it allows for a better approach to repair work while rationalizing resources. This method was applied to a historical structure, during an 18th century church repair project. The assessment methodology provided important information about the conservation state of the timber frame and its structural suitability.

Samples of Kalemişi Work of the Çinili Bath Restoration with Zeyrek

Zeyrek Çinili Hamam, mimarisi, geleneksel ısınma sistemi ve süsleme elemanları
 açısından önem arz eden çifte bir hamamdır. 2010 yılında başlanan Çinili Hamam Koruma-
 Onarım ve Rehabilitasyon Projesi sonucunda yapının hamam işlevi ve ortaya çıkan
 kalemişleri korunacaktır.
 Barbaros Hayrettin Paşa’nın İstanbul’da tesis ettiği evkafına gelir getirmesi amacıyla
 bu yapı inşa edilmiştir. Zeyrek Çinili Hamam’ın bir inşa veya ihya kitâbesi olmamasına
 rağmen, Hassa Başmimarı Sinan tarafından inşa edildiği konusunda bir tereddüt bulunmamaktadır.
 Mimar Sinan’ın yaptığı yapıların listesini veren tezkirelerde ve Barbaros
 Hayrettin Paşa’nın vakfiyesinde hamamın adı geçmektedir. Mimar Sinan, Türk klasik
 hamamlarının temel ilkelerine bağlı kalmak koşuluyla, hamam mimarisi plan şemasında
 her zaman yeni arayışlar içinde olmuştur.
 Restorasyon çalışmaları sonucunda hamamın erkekler ve kadınlara ait soyunmalık
 kısımlarında yapıya ayrı bir boyut kazandıran kalemişleri gün ışığına çıkarılmıştır. Cibali
 yangınları sonrasında gerçekleşen onarımlarda yapılan ilk katman kalemişleri 1850
 senelerine aittir. Günümüze ulaşan en nitelikli kalemişleri ise 1850-1890 yılları arasına tarihlenir. 19. yüzyıla tarihlenen ve iki dönem şeklinde uygulanan kalemişleri bu makale
 ile ilk kez literatüre kazandırılmaktadır. Alt bölümlerin bezemeleri birbiri üstüne uygulanmış
 katmanlar halinde iken duvarların üst bölümlerinde ve kubbe geçişinde yer alan
 siyah-beyaz kalemişi ise tek katman halindedir. Klasik Dönem yapılarına 19. yüzyılda
 eklenen kalemişleri ile bu bezemeler arasında karşılaştırma yapılarak, benzerlikler örnekleri
 ile ortaya konulmuştur.

FEATURES OF CREATION AND RESTORATION OF SUPPORTING GEODESIC NETWORK IN ROAD CONSTRUCTION MEASUREMENTS

The success of the implementation of projects of capital repairs, reconstruction or new construction of roads and man-made structures depends on the quality of geodetic support. Geodetic marking works must accompany the process of construction or repair work. Particular attention should be paid to the peculiarities of the creation and restoration of the geodetic support network in road construction, as these issues have a primary impact on the success of development and implementation of repair and construction projects and therefore affect the entire life cycle of the highway. The laying of points of the geodetic reference network is performed in order to ensure topographic survey at the stage of surveys and to ensure further marking works at the stage of overhaul, reconstruction or new construction of the highway. The project of creating a geodetic reference network must be included in the main work program or compiled separately and agreed with the customer. The project of creating a geodetic reference network must display information on the type of network points, density and location of points, methods of geodetic measurements, coordinate systems and heights, basic requirements for the accuracy of the position of geodetic reference points and requirements for reporting materials in the technical report. The location, type of fastening, construction and external design of the points of the basic geodetic network must ensure the preservation of the spatial position, protection from damage and loss of points. Metal structures of geodetic signs and design elements must be protected from corrosion by a special anti-corrosion coating. The location of the points is determined after the reconnaissance work, study of the initial data and the needs of design, construction and operation. The proposed features of creation and restoration of the basic geodetic network in road construction are reflected in DSTU 9154:2021 «Guidance on performance of geodesic works in road building».

Occupational injuries among non-standard workers in the Taiwan construction industry

Introduction: Global changes in the labor force have led to an increase in non-standard employment (NSE) workers, particularly apparent in the construction industry. These workers have a higher risk of occupational injury and negative health-related outcomes. Method: In this study, relevant literature and the database for construction accidents are examined to identify the classification of NSE in the Taiwan construction industry. Accident reports from 2000 to 2018 are extracted from case reports of the Northern Occupational Safety and Health Center of Taiwan. Pearson's chi-squared test are then employed to analyze a total of 1,612 occupational fatality cases in the construction industry to explore the differences in occupational injuries between NSE and standard employment (SE). Further, characteristics of occupational injuries for different types of NSE in the construction industry are analyzed. Results: The NSE occupational injury rate for older workers over 60 years old is higher, especially for self-employed workers taking on technical work. NSE workers are more expected to suffer occupational fatalities in the small-scale, non-public, and repair projects. Occupational injuries involving self-employed and temporary agency workers are clearly regionally concentrated. Temporary agency workers involved in occupational injuries are most engaged in non-technical work and movement for worker motion with their unfamiliarity with the worksite. Most enterprises did not perform safety management on construction sites for occupational injuries involving NSE workers, especially for self-employed workers. Conclusions: The results show that the hazard characteristics of NSE workers are clearly different from SE workers. NSE workers face inferior job security and protection, especially for self-employed workers. Practical Applications: The results can be used to establish effective occupational safety management policies and programs more efficiently.

Sulfate Freeze-Thaw Resistance of Magnesium Potassium Phosphate Cement Mortar according to Hydration Age.

Concrete structures can be degraded by exposure to environmental stressors such as freeze–thaw cycling and salt corrosion. Magnesium potassium phosphate cement (MKPC) mortar is useful for the rapid repair of such structures but must acquire environmental resistance rapidly. In this study, the freeze–thaw resistance of MKPC mortar specimens of different hydration ages was tested in water and a 5% Na2SO4 solution. The strength, volume deformation, and water absorption rates were compared with those of full-age MKPC mortar specimens (28 d). The phase composition and microscopic morphology of the MKPC mortar specimens before and after corrosion were observed, and the corrosion-resistance mechanism was analyzed. After 225 freeze–thaw cycles in water and sulfate solution, the strength residual rates of the early-age specimen (1 d) were higher than those of the full-age specimen (28 d). The degree of strength attenuation in the 1 d specimen was lower in the sulfate environment than in the water environment. After 225 freeze–thaw cycles, the volume expansion rates of 1 d specimens in water or sulfate were 0.487% and 0.518%, respectively, while those of 28 d specimens were 0.963% and 1.308%. The comparison shows that the 1 d specimen had significantly better deformation resistance under freeze–thaw than the 28 d specimen. After 225 freeze–thaw cycles, the water absorption rates of 1 d specimens were 1.95% and 1.64% in water and sulfate solution, respectively, while those of 28 d specimens were 2.20% and 1.83%. This indicates that freeze–thaw cycling has a greater effect on the pore structure of fully aged mortar than on early-age mortar (1 d). Therefore, MKPC mortar is suitable for the rapid repair of concrete structures in harsh environments. The results form a theoretical basis for winter emergency repair projects. They also further the understanding of the application of MKPC-based materials in extreme environments.

For a reparatory social science

The continuing coronavirus pandemic has combined with other global crises to highlight some of the fundamental challenges of inequality that currently face us. They are global both in their current configuration and their historical constitution. Similarly, any solutions to the challenges represented will be global. The continuing relevance of the social sciences will rest on their ability adequately to conceptualise the global processes involved. It is only by acknowledging the significance of the ‘colonial global’ that it will be possible to understand and address the necessarily postcolonial present that is the context for issues of inequality in the present. This article argues for the need to consider our colonial past as the basis for thinking about contemporary configurations of the global. This is followed by an address of the implications of these arguments for how we understand citizenship and belonging in the present. What is needed is a ‘reparatory social science’ committed to undoing the inadequacies that have become lodged in our disciplines and working towards a project of repair and transformation for a world that works for all of us.

Research on security technology of tower foundation based on precise control of freezing temperature field

Freezing method is used in the main shaft slotting repair project in Chensilou Coal Mine in China. According to the actual conditions of Chensilou Coal Mine, this paper established a numerical calculation model which included the following influence factors: thermodynamic parameters, borehole layout, original formation temperature, groundwater seepage, hot water circulation protection. The calculation results show that the reasonable brine temperature for the freezing project in Chensilou Coal Mine should be controlled between -30 °C and -25 °C and the reasonable freezing time should be 160 days. When the freezing time extends to 80–120 days, the freezing front has developed to the temperature-control hole. In this case, the hot water circulation of the temperature-control hole needs to be started and the hot water temperature is not lower than 20 °C. The freezing construction was implemented in accordance with the optimized brine temperature and freezing time, and the freezing of tower foundation has been successfully avoided. The measured results show that the tower tilts to the northeast as a whole during formation freezing and the tilt values are all less than the allowable value.

Research on Mechanical Response of Polymer Grouting Repair for Longitudinal Cracks in Reconstructed and Expanded Expressway Pavement

Polymer grouting materials have been widely used in road repair projects. In order to study the application of polymer grouting materials in repairing the joint cracks and voids of new and old subgrades in the reconstruction and expansion projects of expressways. According to the phenomenon investigation data, ABAQUS finite element software was used to establish a three-dimensional road mechanical response analysis model, and the mechanical response characteristics of the road before and after polymer grouting were systematically analyzed. The research results of the road which was repaired by polymer grouting show that the shear force between the polymer grouting material and the materials on both sides of the old and new subgrades can repair the cracks at the joint and the diseases in the void area of the new subgrade, so as to reduce the displacement and settlement of the road surface. The maximum dynamic stress peak value of the old and new subgrade road surfaces is located at the load action position, and with the increase of the distance from the load action position, the dynamic stress peak value gradually decreases, showing an M-shaped distribution as a whole. The original stress transfer law of the road structure was changed, so that the dynamic stress of the new subgrade is significantly smaller than that of the old subgrade. The critical surface formed between polymer grouting material and subgrade material has a certain shear strength, which reduces the tensile stress and strain between structural layers. It will improve the bearing capacity of the subgrade and at the same time provide a practical reference for the treatment of longitudinal cracks in the reconstruction and expansion of expressway.

Interlaminar Shear Characteristics, Energy Consumption, and Carbon Emissions of Polyurethane Mixtures

The interlaminar shear characteristics of a polyurethane (PU) mixture composite structure, quantitatively calculating its energy consumption and carbon emissions were analyzed in this study. Inclined shear tests were carried out on thirteen structures without interlaminar treatment, and high-temperature water bath accelerated loading tests were conducted on three composite structures; further, the interlaminar shear strength of the tire trace position after the accelerated loading test was tested to analyze the influence of both the high-temperature water bath environment and loading on the structure. In addition, based on the medium repair project of the Qingdao-Yinchuan expressway, the construction log of PU mixture pavement and asphalt pavement was investigated. Combined with the calculation parameters provided by the United Nations Intergovernmental Panel on Climate Change (IPCC), the consumption and carbon emissions of the two types of mixtures were calculated and compared quantitatively. The results showed that the shear strength between layers of asphalt mixtures, PU mixture and asphalt mixture was less than 2 MPa; however, the shear strength between PU mixture–cement-stabilized macadam and PU mixture–PU mixture was greater than 3 MPa. Therefore, it was recommended to spread a 0.4 L/m2 two-component PU adhesive layer as the interlayer treatment scheme for the structure of asphalt mixture-PU mixture and PU mixture-asphalt mixture; the high-temperature water area and accelerated loading had different effects on the interlaminar shear strength of the three structures. The PUM-16 mixture could effectively reduce energy consumption by 88.3 and 87.2%, carbon emissions by 81.1% and 79.1% in comparison to Stone Matrix asphalt with Nominal maximum particle size of 13.2 mm (SMA-13) and Stone Matrix asphalt with Nominal maximum particle size of 19.0 mm (SMA-20). Thus, the PU mixture was confirmed to be an environmentally friendly road pavement material.