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The purpose of this paper is to show how the time frame for the execution of a construction project in Algeria is rarely respected because of organizational problems and uncertainties encountered while the execution is underway.

A case study on the construction of a metro station is used as a pilot project to show the effectiveness of replacing traditional construction processes by more innovative procedures. Concurrent engineering (CE) is applied to optimize the execution time of the underground structure. A numerical simulation is integrated into the construction process in order to update design parameters with real site conditions observed during the construction process.

The results show that the implementation of CE is efficient in reducing the completion time, with an 18 per cent reduction observed in this case study. A cost reduction of 20 per cent on the steel frame support and a total cost reduction of 3 per cent were obtained.

The study demonstrates that the application of CE methods can be quite valuable in large, complex construction projects. Vulgarizing it as “the solution” to adjust time frame delay, control quality and cost, might be an issue for local construction enterprises in Algeria.

Using the concept of CE by overlapping different activities involved in a construction project and making use of simulation tools in the process at different stages of the execution have resulted in modifying the excavation method and hence reducing the completion times.

Despite widespread interest in the resources and people of Alaska, few libraries outside of the state maintain extensive collections on these subjects. In this article, David A. Hales reviews a multifarious sample of informative materials.

The purpose of this paper is to present the modeling of statistical variation of experimental data using the design of experiments method to optimize the formulation of a high performance concrete (HPC) using materials that are locally available in Algeria. For this, two mineral additions (natural pozzolana and limestone filler [LF]) were used. Both additions are added by substitution of cement up to 25%. To better appreciate the effect of replacing a part of cement by natural pozzolana and LF and to optimize their combined effect on the characteristics of HPC, an effective analytical method is therefore needed to reach the required objective.

The experimental part of the study consisted of substituting a portion of cement by various proportions of these additions to assess their effects on the physico-mechanical characteristics of HPC. A mixture design with three factors and five levels was carried out. The JMP7 software was used to provide mathematical models for the statistical variation of measured values and to perform a statistical analysis. These models made it possible to show the contribution of the three factors and their interactions in the variation of the response.

The mixture design approach made it possible to visualize the influence of LF and pozzolanic filler (PF) on the physico-mechanical characteristics of HPC, the developed models present good correlation coefficients (R² = 0.82) for all studied responses. The obtained results indicated that it is quite possible to substitute a part of cement with LF and PF in the formulation of a HPC. Thanks to the complementary effect between the two additions, the workability could be improved and the strengths drop could be avoided in the short, medium and long term. The optimization of mixture design factors based on the mathematical models was carried out to select the appropriate factors combinations; a good agreement between the experimental results and the predicted results was obtained.

The coefficient of PF in Cs₂₈ model is closer to that of LF than in Cs₇ model, thanks to the complementary effect between LF and PF at the age of 28 days. It was found that the optimal HPC14 concrete (10%LF–5%PF) provides the best compromise between the three responses. It is also worth noting that the use of these two local materials can reduce the manufacturing costs of HPC and reduce carbon dioxide emissions into the atmosphere. This can be an important economic and environmental alternative.

For 28 years Alaska, like the vast majority of the nation, has struggled with growing prison populations and shrinking budgets. In 1995, the Alaska Department of Corrections, faced with sanctions unless they ameliorated their crowded prison conditions, looked to the popular practice of contracting out its correctional operations by sending 650 prisoners to a private out-of-state prison. But, as the costs of prisoner litigation and transportation mounted, the state began to consider building its own private prison, a decision which many state lawmakers and business entrepreneurs argued would allow the state to stretch scarce dollars by providing cheaper and better quality prisons, return millions of dollars to the state economy, and create permanent jobs. In this decision case, students are required to put themselves in the role of the Alaska Legislature to determine whether they should permit the building and operation of a private prison in one of Alaska's remote communities. The students must analyze and juggle the complex and often competing set of objectives, values, and political tensions intrinsic to all privatization decisions.

To come up with a prudent decision on the installation of an appropriate green wall (GW) on buildings, this study presents a novel decision-making algorithm. The proposed algorithm considers the importance of barriers hampering GW adoption, as well as their relationships with regard to different types of GWs existing in a contextual setting.

The proposed methodological approach is based on the integration of qualitative and quantitative techniques by employing focus group discussion, fuzzy-based best-worst method and fuzzy TOPSIS.

Based on the experiences of qualified experts involved in related projects in Hong Kong, the following conclusions are drawn: (1) cost, installation and maintenance-related barriers are perceived to have the highest importance, (2) modular living wall system is the most suitable GW system for the context of Hong Kong and (3) existing barriers are found to have a pivotal role in the ranking of the most suitable GW systems.

The findings provide valuable insight not only for policymakers and stakeholders, but also for establishing a methodological approach that can assist decision-makers in identifying the most beneficial GW system rather than the most applicable one. This could have significant implications and introduce potential changes to the common way of practice within the industry and lay the foundation for wider adoption of GW.

While previous studies have investigated the sustainability-related issues of GW façade applications, the current body of knowledge is deprived of a comprehensive methodological approach for the selection of the most suitable GW systems.

Discrimination law has evolved from litigating or prosecuting overt, individual cases of egregious behavior solely by means of anecdotal evidence and eyewitness testimony. Statistical evidence came to bear the imprimatur of the United States Supreme Court in the Seventies as a probative means of discerning guilt or liability, and has been used to shore up patterns of prejudice at a systemic level since. Courtrooms of the Twenty-First Century have struggled to define discrimination through a quantitative lens, nonetheless relying on qualitative evidence to assist the factfinder in rendering a verdict. Some definitions carry more precision and accuracy than others. Consider the inflammatory National Law Journal's indictment of the United States Environmental Protection Agency (‘EPA’) as an example of the latter. In 1992, the National Law Journal ran a Special Investigation of the EPA, claiming that the federal government had fostered a racist imbalance in hazardous site cleanup and its pursuit of polluters. Kudos to the columnists for bringing environmental equity into the spotlight of public debate and for forewarning and encouraging the EPA to conduct its enforcements reflectively, in order to avoid being on the receiving end of a Title VI lawsuit. Nonetheless, the methodology used by the National Law Journal belies a total understanding of the bureaucratic structure that pursued these actions and of the notion of statistical significance. This Article confines itself to Region X's actions between 1995 and 1999, applying linear regression and other statistical tests to determine whether biases, found using the National Law Journal's naive methodology, stand after due consideration of chance. The NLJ approach finds evidence of bias, but the author also conducts more complicated and appropriate analyses, such as those contemplated by the National Guidance. After issuing some provisos, the author dismisses charges of racism or classism. While the National Guidance represents a positive first step in identifying environmental justice communities, those with an above-average proportion of lower-class or non-Caucasian inhabitants, it lacks statistical sophistication and econometric depth. This Article concludes by recommending the use of normalized racial distributions, Gini coefficients, and Social Welfare Functions to the EPA and to other organizations conducting environmental justice analysis.

The study aimed to explore the effects of mineral admixtures – especially limestone filler (LF), brick powder (BP) and ceramic powder (CP) – on the performance of self-compacting sand concrete (SCSC). It studies their effect on mechanical properties and mass loss when exposed to acidic solutions (H2SO4 5% and HCl 5%) over periods of 28, 90 and 180 days. The study seeks to develop SCSC technology by taking advantage of locally available sand resources.

Using an experimental design, the study explores different formulation parameters, including the use of silty sand (AS) and dune sand (DS) in fixed proportions, where AS constitutes 70% and DS 30% of the total sand content. The superplasticizer ratio (SP) and water-to-binder ratio (W/B) are constant with varying amounts of mineral additives. The study immerses SCSC samples in acidic solutions (5% H₂SO₄ and 5% HCl) for 28, 90, and 180 days to evaluate mass loss and mechanical properties. This endeavor to advance such concrete technology is motivated by the desire to incorporate sand concrete into the realm of self-compacting concrete technology while also harnessing the advantages of locally available sand resources, particularly dune sand, which is abundant in the southern regions of Algeria.

SCSC results with mineral additives showed enhanced resistance in both tensile and compression tests, indicating improved durability compared to the reference sample without additives. However, excessive proportions of BP (>60%) or CP led to exceptions in this trend An exception to this trend was observed when BP was added in proportions exceeding 60% or when CP, indicating potential limitations in some additive formulations. Overall, the research provides valuable insights into improving the performance and durability of SCSC through the strategic incorporation of mineral admixtures, contributing to advances in self-compacting concrete technology.

1 – Valorization of local materials and recycling of waste: DS, LF, BP and CP, which are available in great quantities in the south of Algeria; 2 – Combination, at the same time, of alluvial sand and dune sand as aggregate and LF, BP and CP as filler. 3 – Application of the design of experiments method methodology for the optimization of these elements of the new sand concrete studied. The new building material elaborated present indeed a technical, economic and environmental interest.