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Natural pozzolans are defined as either raw (volcanic material, limestone) or calcined natural materials (burnt shale, calcined kaolinite) with pozzolanic properties. Historically, they are among the oldest materials that have been used in combination with lime for construction purposes. For example, Santorin earth is a natural pozzolan from a volcanic eruption around 1500 BCE on an island of the same name in Greece. Over the last decades, research into cement matrices has been changing direction, owing to deeper environmental concerns over the impact of the cement industry and its consequences for climate change. Global environmental policies are increasingly strict, prioritizing the re-use rather than the disposal of industrial wastes. In this context, one of the biggest challenges is the search for strategies that promote the industrial rotation of high volumes of wastes in their productive cycles. The main purpose of this research is to widen the existing knowledge base on the behavior of new mineral pozzolans of high added value in the cement sector, lending special attention to paper sludge wastes generated in the process of paper manufacture, in which recycled paper is used as a raw material. The results to date show that, once thermally activated (in the range of 650–700°C), paper sludge turns out to be an alternative source of recycled metakaolin. This product is characterized by its high pozzolanic activity and improved performance with regard to the benefits of certain binary cements. The possibility of incorporating this industrial waste in cements along with other already standard pozzolans focuses, as mentioned, on the notable increase in the production of these types of cements. This is due, at present, to the extensive constructive applications for type-II cements (single additive) and to their lower economic and energetic costs that also makes them more suitable in times of economic crisis. In the present paper, the influence that pozzolan blends (activated paper sludge and fly ash) have on the reaction kinetics of ternary blended cements (6 and 21% of replacement) is evaluated, paying special attention to the identification and evolution of hydrated phases with increasing reaction times. The results obtained represent a pioneering research line at a global level and represent a starting point for future investigations because in the case of using paper sludge, release of CO2 from organic matter is very low and is listed as zero release

This paper introduces the study on treatment on the secondary biochemical effluent of pulp and paper wastewater by ozonation, and investigates the effects of the ozonation process on the wastewater COD, chroma, UV 254 and turbidity removal efficiency during ozone dosage, contact time and so on. The results showed that ozonation treatment effect was good, and with the increase of ozone dosage and contact time, the wastewater COD, chroma and UV 254 experimental conditions removal rate was increasing, and the optimum were that the ozone dosage was 126.46~147.37mg/L and contact time was 1.30~1.74h. Ozonation has a certain removal efficiency for turbidity, and turbidity removal rate was in a large range of 1.88~77.51%, but there is no obvious correlation with the ozone dosage and contact time.

Over the last few years, students taking the Introduction to Geotechnical Engineering course at Tufts University have performed term projects where they develop written reports and oral presentations on various topics in geo-engineering. This paper presents how these efforts have enhanced the learning experience of the course. Specifically, the paper presents how the project is integrated into the course, assessment methods used for grading, and the value such projects have had on student learning, based on post-course evaluations. A shortened example of a student’s work is presented. It can be concluded that the project allows not only a deeper appreciation of geo-engineering by the students, but also provides an avenue for students to practice their communication skills; one of the ABET Criterion 3 outcomes.

A complex cleanup project that included dredging and capping of contaminated sediment, construction of two breakwaters, habitat enhancement, upgrade of a seasonal small craft facility and installation of new aids to navigation was completed by the Port of Anacortes, Washington in collaboration with the Department of Ecology, Washington and potentially responsible parties (PRP). The complexity of project site physical processes, extent of dredging, and strict regulatory requirements on the clean-up action necessitated an innovative engineering approach to all above elements of the project. The approach also included application of the most advanced coastal engineering modeling tools including wave, tidal flow, sediment transport and stability, and coastal geomorphology hydrodynamic simulators. Based on analysis of the numerical modeling results, optimal engineering decisions were made for design and construction of detached breakwaters, dredging and removing a portion of the contaminated sediment, capping of the remaining contaminated sediment, and removing the old deteriorating creosoted sheetpile wall breakwater. Also, the results of the study determined the possibility of creating a sheltered eelgrass habitat and year-round small craft facility for different types of activities such as fishing, kayaking, and sailing.

The FEMA P695 Methodology, developed through the recent ATC-63 Project, incorporates ground motion guidelines that include a so-called Spectral Shape Factor (SSF). This SSF adjusts the predicted collapse capacity of the building to account for the spectral shape of ground motions. This paper explains how aspects of this new FEMA P695 Methodology could be adapted for use in refining the target displacement equation (i.e. inelastic displacement demand) in the ASCE/SEI 41 Nonlinear Static Method to account for spectral shape. The final result would be an additional coefficient (termed the “spectral shape coefficient”) that would reduce the target displacement for sites where the ground motion is expected to have a less damaging spectral shape. This paper outlines how one would compute this spectral shape coefficient for any site and building of interest, and then explains the additional work needed to implement this new coefficient into ASCE/SEI 41. An example is provided to illustrate the effect that the new coefficient has on the computed target displacement. For a 2% in 50 year motion at a San Francisco California site, application of the spectral shape coefficient results in a 40% reduction in the target displacement.

Tunnel and large cut-and-cover structure response to earthquakes is dominated by the surrounding ground, and, contrary to shallow-founded structures, does not depend on the inertial properties of the structures themselves. The focus of the underground design is on the free-field deformation of the ground and its interaction with the structure, i.e., a soil-structure interaction phenomenon. This paper summarizes the performance in recent past seismic events of deep, large underground structures, and then elaborates on their design approach: geotechnical, seismic criteria and structural factors. Analytical models are examined and conclusions drawn about their advantages and limitations. A general approach to the design of deep underground structures is illustrated through the on-going design of a particular project.

The Port of Anacortes, Washington is working on implementation of a complex clean-up project that includes excavation and dredging of contaminated sediment, capping the remaining sediment, constructing the detached attenuator, removing the old Port breakwater, and constructing a habitat and a pier for recreational activities. The complexity of the clean-up project is exacerbated by intense wave action and ongoing shoreline and bottom slope erosion. In order to determine a technically feasible and environmentally acceptable engineering solution for the clean-up project, the Port completed a comprehensive coastal engineering study that included extensive numerical modeling to evaluate wave action, tidal flow, and sediment stability. Based on results of the study, an optimal solution was found; preliminary and final engineering were completed; and environmental clearances were obtained. Project construction started in July 2009 and is scheduled for completion in March 2010. Copyright 2010 ASCE.

Waste paper sludge, or fiber-clay as it is often identified when used as a resource for recycling and reuse in new applications, has over the last several years become a vital component in several geotechnical uses and a variety of manufactured products. Among the major reuses of fiber-clay has been its use as a cover material for sanitary landfills, after thorough laboratory and field evaluations. Because of the high kaolin clay content in the manufacturing of paper products, there is a high residual of clay in waste paper sludge from the manufacturer's waste water treatment plants. The reuse of cover material has resulted in a cost avoidance for the waste generator, reducing or eliminating disposal costs as well as eliminating the need for finding a disposal site. There are also cost savings for landfill operator and owners who otherwise would have to secure an adequate clay source. When compacted, most fiber-clays exhibit adequate hydraulic conductivity and shear strength for use in landfill covers. In addition to its use as a cover material, the fiber-clay, when combined with a pozzalonic material such as fly ash and aggregate, has been used as one of the major components for road beds, both as subsurface base and as a finished surface for remote access and secondary roads. Additional uses include the manufacturing of kitty litter and animal bedding. This paper will review the history and technology involved in evaluating the potential uses of fiber-clay. Extensive laboratory and field testing has been done to determine its shear strength, slope stability, hydraulic conductivity, and settlement potential. Information is presented on the various testing techniques and results, together with examples of actual field projects.

Despite a great deal of interest in risk management of dams and water resource facilities during the latter part of the 20 th century, few opportunities to apply these emerging concepts arose in practice. This paper examines the fundamental principles of risk assessment and decisions concerning their management can not be carried out in the traditional way decisions concerning the safety of dams were made in the past. A framework for managing the risks posed by dams is presented as is a proposed approach to determining when risk assessment is appropriate, and the professional and societal structures and institutions that are required to permit implementation of risk assessment in dam risk management.