Search

A new logistic model tree (LMT) model is developed to predict slope stability status based on an updated database including 627 slope stability cases with input parameters of unit weight, cohesion, angle of internal friction, slope angle, slope height and pore pressure ratio. The performance of the LMT model was assessed using statistical metrics, including accuracy (Acc), Matthews correlation coefficient (Mcc), area under the receiver operating characteristic curve (AUC) and F-score. The analysis of the Acc together with Mcc, AUC and F-score values for the slope stability suggests that the proposed LMT achieved better prediction results (Acc = 85.6%, Mcc = 0.713, AUC = 0.907, F-score for stable state = 0.967 and F-score for failed state = 0.923) as compared to other methods previously employed in the literature. Two case studies with ten slope stability events were used to verify the proposed LMT. It was found that the prediction results are completely consistent with the actual situation at the site. Finally, risk analysis was carried out, and the result also agrees with the actual conditions. Such probability results can be incorporated into risk analysis with the corresponding failure cost assessment later.

Abstract Many scientists are now focusing their attention on the utilization of valuable industrial or agricultural wastes as the primary raw material for the construction sector. These wastes, on the other hand, are affordable and readily accessible, making them ideal for commercial use while also contributing to the reduction of environmental degradation. Wheat straw ash (WTSA) is a kind of agricultural waste that has the potential to be utilized in concrete. Although many researchers are focused on utilization of WTSA in concrete. However, an updated review is required which provides easy access for the reader to get an idea about the benefits of WTSA in concrete. Therefore, this study provides a comprehensive review of the utilization of WTSA as a concrete ingredient. Physical and chemical compositions of WTSA, flowability, mechanical strength (compressive, flexure, tensile strength, and elastic modulus), and durability properties (permeability, carbonation, ultrasonic pulse velocity, alkali-silica reaction and chloride attacks) are the main aspects of this review. Results indicate that the performance of concrete improved with partial substitutions of cement with WTSA but simultaneously decreased the flowability of concrete. The optimum dose is important as higher dose results in decreased mechanical strength. The typical optimum dose ranges from 10 to 20% by weight of the binder. The performance of concrete in terms of durability was also improved but less research is carried out on the durability performance of concrete with WTSA. Additionally, despite WTSA's improvement in mechanical strength, concrete still exhibits lower tensile strain, which leads to brittle failure. Therefore, it was recommended that further study should be done to increase its tensile strength.

The idea of using agricultural and industrial waste materials in concrete helps to develop alternatives for protecting the environment, compensating for the shortage of environmental sources, and resolving the waste dumping issue. Environmental awareness about possible adverse effects has substantially expanded, and, consequently, recycling or utilizing agricultural and industrial waste by-products has become an increasingly desirable option for waste disposal. A review of corn cob ash (CCA) use in the construction industry is provided, and emerging trends in fresh properties, strength properties, durability characteristics, and microstructural properties are evaluated. The results show that adding CCA to concrete is advantageous for waste reduction and sustainable development. Furthermore, the optimum substitution of CCA is important. Although different researcher recommends different optimum substitution of CCA due to different source. However, the typical range of optimum substitution of CCA varies by 5–10% by weight of the binder. Therefore, the review recommends that CCA can be utilized in concrete for up to 10% without any harmful impact on concrete qualities. To close the possible research gap, a thorough investigation of the chemical composition of CCA from a different source and durability factors including alkali-silica reaction, shrinkage, and creep properties must be performed.

Numerous scientists have studied basalt fiber (BF) reinforced concrete and found encouraging results. However, information is scattered, and compressive assessment is yet necessary to collect the data from prior research on BF, present research advancement, and future research guidelines of BF reinforced concrete. Furthermore, mostly research focus to review on strength and durability aspects of BF reinforced concrete while no researched focus on thermal properties, microstructure analysis and environmental benefits of BF reinforced concrete. Therefore, the primary focuses of this paper are BF treatment, BF reinforced concrete performance at high temperatures, microstructure analysis, environmental advantages, and application in civil engineering. Results show that BF-reinforced concrete performs much better than traditional concrete at high temperatures. Additionally, the use of BF enhanced the heat conductivity of concrete. BF addition to concrete seems to have reduced interfacial transition zone (ITZ) fractures, according to a microstructure study. When opposed to traditional steel fibers, BFs may be thought as reinforcements that are less harmful to the environment. The study also highlights the significance of BFs in the building industry. The assessment also identified research gap research for further studies.

Competitive advantage significantly matters for modern construction organizations as it promotes the sustainable development and safety management of projects. UK construction organizations have greatly suffered from a lack of safety and sustainability of project management in infrastructure development projects because of the COVID-19 pandemic. Post-COVID-19 UK infrastructure development projects are uncertain in the context of organizational competitive advantage as they cannot maintain sustainable project management. This study was conducted to identify, rank, and present a framework of factors influencing the competitive advantage of UK organizations. The study design involved identifying factors from the current literature, after which the most relevant factors were filtered with the help of semi-structured interviews with 15 experts. A pilot survey was conducted then, involving 192 respondents, after which a reliability test and exploratory factor analysis (EFA) were conducted on the results. A primary questionnaire survey involving 250 respondents was conducted, after which RII and confirmatory factor analysis (CFA) were conducted on the final data. A total of five subgroups were found to be significant in the CFA, such as Resources and Policies, Quality and Delays, Motivation and Expectation, Management and Environment, and Government and Business. It is recommended based on findings that the construction organizations of the UK have to consider working on identified factors to maintain a competitive advantage in establishing sustainable project management solutions for post-COVID-19 UK infrastructure development projects.

Natural fibers are an excellent alternative since they are inexpensive and easily accessible in fibrous form. Several researchers claim that jute fiber (JTF) can be used in concrete to improve its strength and durability performance. This review describes the characteristics and potential uses of some jute fibers in concrete. The main theme of this review is to summarize the effect of JTF on fresh properties of concrete, strength parameters, and durability characteristics. It can be concluded that jute fibers improved strength and durability aspect but decreased the fluidity of concrete in a similar way to synthetic fibers. However, there is little research available on the durability of concrete reinforced with JTF. Furthermore, the optimum percentage of JTF in concrete is critical as the higher dose adversely affects strength and durability characteristics due to lack fluidity. The typical range of optimum dose of JTF varies from 1% to 2% depending on the length and diameter of jute fibers. The review also identifies the key for future researchers to further, enhance the properties of concrete reinforced with JTF.

Despite being strong under compression, concrete is rather weak when subjected to tensile stress. Concrete has been reinforced with a variety of materials over time in order to resist tensile stresses. Among various types of fibers, polypropylene fiber, which is available in a range of sizes, is being used to strengthen concrete. The fiber also increases the concrete’s toughness, durability, and low permeability. Polypropylene fibers may be utilized in place of conventional reinforcement, according to a number of researchers. The aim of this study is to collect information from already carried out research on polypropylene fibers. Important characteristics of concrete, such as workability, compressive, tensile, and flexural strength, are reviewed. The review also explores cracking behavior and failure modes of polypropylene fiber reinforced concrete. Furthermore, durability aspects, such as water absorption, porosity, dry shrinkage, and microstructure study (scan electronic microscopy), were also reviewed. Results indicate that polypropylene fiber improved the mechanical strength and durability of concrete (particularly tensile capacity) but decreased the flowability of concrete. The optimum dose is important, as a higher dose adversely affects strength and durability due to a lack of flowability. Scanning electronic microscopy results indicate that the polypropylene fibers restrict the propagation of cracks, which improves the strength and durability of concrete. The review also indicates that shrinkage cracks are considerably reduced with the addition of polypropylene fibers. Finally, the review also provides future research guidelines for upcoming generations to further improve the performance of polypropylene fibers that reinforce concrete.

Metakaolin (MTK) has received a lot of interest in the past two decades as a supplemental cementitious ingredient. MTK is actively being utilized in concrete and there is a large body of literature on the characteristics of concrete containing MTK. A rigorous evaluation of the use of MTK in concrete, however, is lacking, which is required to better know its (MTK) benefits, mechanisms, past and current progress. As a result, the objective of this study is to deliver an overview of MTK utilized in concrete. The physical and chemical characteristics of MTK, as well as the hydration, workability, mechanical qualities, hydration durability, and microstructure analysis of MTK-based concrete, are discussed. A comparison of the findings of diverse literature is presented, as well as some key recommendations. The findings suggest that adding MTK to concrete enhances certain characteristics, particularly mechanical capabilities, but decreases concrete flowability. Improvement in the durability of concrete with MTK was also observed but, for this, less information is available. For optimal performance, the right dosage is crucial. The typical ideal range is between 10 to 20% by weight of the binder. Further research gaps into the characteristics of concrete containing MTK are also recommended.