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This research focuses on achieving early strength of cement-based materials through the hybrid nucleation acceleration method. Through the study of various mortar mixtures, which incorporate components such as ordinary Portland cement (OPC), fine limestone powder (with a particle size of d50: 1 μm), coarse limestone powder (with a particle size of d50: 12 μm), calcium silicate hydrate (C-S-H) nucleation seeding agent, and calcium nitrate (CN), the effect of the hybrid nucleation acceleration method was investigated. When OPC was substituted with 20% fine limestone powder, a strength of 13.5 MPa was achieved at 6 h, whereas the use of coarse limestone powder only yielded 3.5 MPa within the same time frame. The mortar containing 2% C-S-H nucleation seeding agent reached an impressive 16 MPa at 6 h. Meanwhile, through the synergistic combination of fine limestone powder and C-S-H nucleation seeding agent, the 6 h early strength attained an impressive 19 MPa. The micrograph revealed that the hybrid nucleation acceleration method significantly promoted the formation of a dense network of C-S-H within the paste, thus enhancing the packing density. Measuring the heat release demonstrated that the samples accelerated with the C-S-H nucleation seeding agent and fine limestone reached the peak 160 min earlier than the OPC sample, indicating a faster hydration process. The hybrid nucleation accelerated concrete (HNAC) achieved strengths of 20 MPa and 27 MPa within 6 and 8 h, respectively, whereas the 28-day strength surpassed 70 MPa. The concrete equivalent mortar (CEM), derived from concrete, attained a compressive strength of 25 MPa within 8 h, making it suitable for repair applications. The modulus of rupture (MOR) was 7.31 MPa at 8 h and increased to 17.27 MPa at 28 days. Overall, the developed concrete and CEM with the novel hybrid nucleation acceleration method allowed for high early and long-term strength for fast-track construction to be attained.

High-rise building construction projects in DKI Jakarta frequently encounter delays, which lead to increased project costs and penalty risks. These delays also adversely affect sustainable construction by escalating material and resource consumption as well as energy usage. Accelerating project completion can enhance cost efficiency while mitigating negative environmental and social impacts. This study aims to analyze and compare the effectiveness of three project acceleration methods—fast track, crashing, and a combination of both—in expediting the completion of high-rise building construction projects. A case study was conducted on a project with a contract value of Rp156,757,450,806.72 and a planned duration of 531 days. The research utilized secondary data, including work volumes, project schedules, and the 2023 Analisa Harga Satuan Pekerjaan (AHSP). Microsoft Project was used to identify the critical path and to calculate potential time savings and additional costs associated with each method. The results indicate that the combination method (fast track and crashing) yields the most significant time savings, reducing the project duration by 119 days (to 412 days). The fast-track method reduces the duration by 76 days (to 455 days), while the crashing method achieves a reduction of 64 days (to 467 days). In terms of cost, the combination method incurs the highest total cost of Rp164,016,076,094.90, whereas the fast-track method maintains the original budget of Rp156,757,450,806.72. Risk analysis reveals that the combination method introduces the highest complexity, with potential risks including quality degradation, worker fatigue, and increased management challenges. Therefore, while the combination method offers the greatest time reduction, its implementation requires careful consideration of associated costs and risks.

Background Scientists can play an important role in policymaking by providing evidence and consensual expert opinion on the state of scientific knowledge. Delphi surveys have been widely used to develop consensus on a topical issue, yet not compatible with public health crisis situations requiring rapid decisions. We developed a fast-track Delphi process, providing experts with a structured approach to rapidly develop and quantify consensus in support of informed policy decisions. Methods We identified key elements of consensus-building techniques through a literature review and derived methodological procedures that served as the basis for the elaboration of the new process. Selected methodological experts provided advice on necessary adjustments. The process was pilot tested using a real-world public health issue. Results The fast-track Delphi process is a hybrid approach between a conventional Delphi and the nominal group technique: one group session followed by two rounds of e-questionnaire, with predefined steps. We developed an ad hoc toolkit (REDCap templates, R code for analysis and production of reports, user guide) to overcome time constraints, which we pilot tested with experts. The feasibility test conducted in 18 days in the field of tobacco control demonstrated the applicability and usefulness of the process in real-world conditions. Conclusions We strongly believe that this fast-track Delphi process has the potential to help inform policy decisions in various types of crises, including emerging diseases or novel potentially harmful products.

Fast-track construction has recently become the prevailing construction approach globally. It enables owners and developers to make rapid returns on investment through shortened construction periods. This strategy has many effects on the industry; therefore, four groups of factors were studied in this project: (1) financial, (2) logistics and finance, (3) management, and (4) legal. A 22-question survey was distributed to 155 professionals in the construction industry, who evaluated the impact of the stated factors on a 5-point scale. The results revealed a high level of consistency determined through Cronbach’s alpha, and a positive correlation was found by Spearman’s rank coefficient. The Relative Importance Index was used to rank the factors based the evaluation by the professionals, resulting in the following impact ranking: (1) poor communication among design and construction teams, (2) large amounts of rework, (3) low quality of work by the contractor, (4) design errors, (5) late or insufficient payment according to terms agreed with the client, and (6) unavailability of materials in the market. By providing a quantitative RII model to evaluate fast-track project management performance with the use of corresponding performance indicators, this study will benefit industry practitioners and researchers as it identifies the most significant factors that impact fast-tract project management performance.

Concurrent engineering through overlapping of activities (i.e., fast-tracking) has been used as a schedule acceleration technique. Fast-track construction projects are generally recognized as riskier and subject to risks arising due to the concurrency of work. This work reports the risk perception of construction professionals to three different degrees of overlapping. Semi-structured interviews were used to collect the data, and the analysis applied data transformation and descriptive statistics. The risks were mainly perceived in the middle degree of overlapping and in activities occurring earlier in the schedule. The low and high degrees of overlapping were mainly perceived as having no risk or not being feasible, respectively. The four risk types accounted for most of the perceived threats: construction error, design change, crew interference, and poor construction productivity. The findings of this study suggest that construction professionals perceive risks differently based on the amount of activity overlapping. It is consistent with previous studies that found that risks decrease as the project advances and that fast-track projects face additional risks.

Concrete composite slab system, comprised of two half-slabs connected integrally through shear connectors, has gained popularity due to fast-track construction of bridges and buildings. Flexural performance and level of composite action of composite slab system depend on its interface shear connection. In the present study, the behaviour of composite slab system with different levels of interface shear design is assessed through experimental and numerical investigations. From the investigations carried out on concrete composite slabs, it is clearly identified that the interface cohesion is an important parameter which contributes to the stiffness of the system. It is also observed that the concrete composite slabs showed load-displacement response similar to that of control full slab, irrespective of the number shear connectors provided, when the cohesion mobilised is sufficient to cater to the shear demand. It is also observed that in the absence of contribution from interface cohesion, full composite action cannot be achieved even when full shear connection design is provided based on shear friction alone. Furthermore, in the absence of the interface shear reinforcement, the displacement sustained by the composite slab is much lower and failed at lower ultimate displacement compared to that of the control full slab.

Fast-track construction projects are becoming increasingly prevalent in the construction industry, particularly where completion time is essential. A high adoption rate in some of the Gulf Cooperation Council (GCC) countries countries and the lack of a conceptual understanding of the challenges inherent in such may jeopardize the future sustainability of the construction sector. To make an informed decision about adopting a fast-track construction method, it is necessary to first identify the opportunities and challenges associated with it. Therefore, this study examines the critical challenges impeding the performance of Qatar’s fast-track construction projects. The research findings were analysed and triangulated using a real-life project as a case study and several data sources. The results of the research identified four critical categories of barriers: design and coordination-related, scope or change orders-related, material and equipment-related, and contractual-related barriers. In addition, strategies such as accurate information, constructability assessment, early involvement of operations and maintenance personnel, and the use of an effective change control system were identified for addressing the identified challenges. The findings are beneficial to professionals who are currently operating or planning to undertake construction projects in Qatar or other Gulf Cooperation Council (GCC) countries countries. This study recommends that project managers be more attentive to key barriers in order to improve the performance of fast-track projects and to meet clients’ objectives.

Infinite Consulting Engineers’ innovative precast concrete grandstand design helped the Blouberg Local Municipality to fast-track the construction of a large community sports and recreational centre in Senwabarwana, Limpopo. The technology also provided a more cost-effective means of building these structures and an end product of a higher quality, both in terms of durability and aesthetics.

Concor is hard at work on the latest student accommodation project in Braamfontein, Johannesburg – a much-needed contribution to the national shortage of these facilities. The fast-track venture is scheduled for completion in just 12 months and began in November 2021.

Purpose Following the global financial crisis in 2008, the construction sector in UAE has been facing emergent criticisms for growing adversarial culture and rising prevalent claims and disputes between stakeholders. The complex, large size and fast track nature of construction projects in UAE, make project management very challenging under the commonly used traditional procurement routes. This paper aims to examine whether implementing collaborative procurement approaches can facilitate resolving the escalating number of claims and disputes in the UAE construction industry. Design/methodology/approach Considering the nature of the study, a quantitative method was selected to realize the research objectives. The questionnaire was uploaded using an online survey facility and distributed through e-mails and professional networks. The questionnaire was piloted with experts to assess whether the questions are unambiguous, easy to respond and intelligible. The feedback received was mostly positive with few comments and recommendations. The pilot responses were incorporated and the questionnaire was modified before the final sending out. The questionnaire survey consisted of six main sections to fulfill the research objectives. Findings Around three-quarters of the experts believe that the relationship is adversarial, with a lack of trust, win-lose attitude, with dismissive and opportunistic behavior. The survey reveals that the top causes of claims and disputes comprise the following: variations because clients initiated change requests; contractors selection on low bid only rather than including quality and performance considerations; and unfair risk allocation where majority of risks are transferred to contractors. The findings also identify eight collaborative practices, which have crucial positive impacts such as early identification of problems, better communication and enhanced trust and teamwork. Originality/value This research contributes to the enhancement of the management of claims and disputes for construction projects, which encompasses the following: the key characteristics of collaborative arrangements to improve the adversarial construction culture comprise: mutual respect, openness, fairness and non-opportunistic behaviors; the foremost roles of collaborative procurement in reducing claims and disputes embrace: early identification and resolution of problems, enhanced trust and teamwork spirit, improved relationships and better quality communication; the major practical barriers of implementing collaborative approaches incorporate: lack of awareness of their benefits, primitive legal framework of partnering arrangements and lack of transparency in procurement processes.