Compaction

This paper discusses both occupational health risks to workers and environmental health risks to residents and workers. The report presents an overview of the available health literature for causes of diseases, injuries, and accidents from solid waste management collection, treatment, and disposal technologies. Illnesses discussed include infectious diseases, allergies, respiratory damage, and cancers. Some diseases are derived from direct ingestion of infectious micro-organisms, others involve infection through contamination of the food chain, whereby animals or other vectors have ingested infectious micro-organisms. Injuries include joint and spinal damage, fractures, puncture wounds, damage to eyes and ears. Accidents include slides from unstable disposal piles, cave-ins of disposal site surfaces, fires, explosions, being caught in processing equipment, and being run over by mobile equipment. As the next steps toward improving occupational and environmental health and safety in s...

For two decades, solid waste components in Bank projects have focused on collection of solid wastes, with equipment provided to upgrade operations at existing open dumps. Since early 1990, the private sector has become increasingly involved in the collection, disposal, and treatment of solid waste, and Bank projects have placed greater priority on implementation of new sanitary landfills. The following guidance provides an examination of some of the issues which need to be addressed in landfill siting and design.

In an effort to understand the present-day thermal structure of the Jeanne d'Arc Basin, we derive matrix thermal conductivity values, using a geometric mean model, from thermal conductivity values of thirteen lithologic end-members (of which seven are measurements on materials from the Jeanne d'Arc Basin) and lithological data. Temperature corrections to thermal conductivity are made for both matrix and pore water. In-situ thermal conductivities were obtained after correcting for the effect of porosity, which we estimated from both lithological information and digital well logs. Calculated thermal conductivities of the formations range from 1.46 to 2.65 W m -1K -1. The heterogeneity of formation thermal conductivity is caused by at least two factors. The first is lithological variation due to facies change. The second is due to different degrees of compaction. Under-compacted intervals (overpressure zones) are characteristically of lower thermal conductivity. The surface heat flow density calculated with an inverse method in seventeen wells varies from 37.8 to 60.7 mW/m 2. This study indicates that surface heat flow density values estimated without porosity corrections may be 15% higher than those with porosity corrections. We also demonstrate the sensitivity of modelled timing of maturation to thermal conductivity estimations.

Red mud is a waste material generated by the Bayer Process widely used to produce alumina from bauxite throughout the world. Approximately, 35% to 40% per ton of bauxite treated using the Bayer Process ends up as red mud waste. Because of storing issues, the waste negatively affects the environment. To solve this problem, it is essential to investigate different uses for red mud waste. The potential use of red mud for the preparation of stabilization material is presented in this study. This study examines the effects of red mud on the unconfined compressive strength, hydraulic conductivity, and swelling percentage of compacted clay liners as a hydraulic barrier. The test results show that compacted clay samples containing red mud and cement–red mud additives have a high compressive strength and decreased the hydraulic conductivity and swelling percentage as compared to natural clay samples. Consequently, it is concluded that red mud and cement–red mud materials can be successfully used for the stabilization of clay liners in geotechnical applications.

Compressional and shear-wave velocities ( V p and V s) of 210 minicores of carbonates from different areas and ages were measured under variable confining and pore-fluid pressures. The lithologies of the samples range from unconsolidated carbonate mud to completely lithified limestones. The velocity measurements enable us to relate velocity variations in carbonates to factors such as mineralogy, porosity, pore types and density and to quantify the velocity effects of compaction and other diagenetic alterations. Pure carbonate rocks show, unlike siliciclastic or shaly sediments, little direct correlation between acoustic properties ( V p and V s) with age or burial depth of the sediments so that velocity inversions with increasing depth are common. Rather, sonic velocity in carbonates is controlled by the combined effect of depositional lithology and several post-depositional processes, such as cementation or dissolution, which results in fabrics specific to carbonates. These diagenetic fabrics can be directly correlated to the sonic velocity of the rocks. At 8 MPa effective pressure V p ranges from 1700 to 6500 m/s, and V s ranges from 800 to 3400 m/s. This range is mainly caused by variations in the amount and type of porosity and not by variations in mineralogy. In general, the measured velocities show a positive correlation with density and an inverse correlation with porosity, but departures from the general trends of correlation can be as high as 2500 m/s. These deviations can be explained by the occurrence of different pore types that form during specific diagenetic phases. Our data set further suggests that commonly used correlations like ``Gardner's Law'' ( V p-density) or the ``time-average-equation'' ( V p-porosity) should be significantly modified towards higher velocities before being applied to carbonates. The velocity measurements of unconsolidated carbonate mud at different stages of experimental compaction show that the velocity increase due to compaction is lower than the observed velocity increase at decreasing porosities in natural rocks. This discrepancy shows that diagenetic changes that accompany compaction influence velocity more than solely compaction at increasing overburden pressure. The susceptibility of carbonates to diagenetic changes, that occur far more quickly than compaction, causes a special velocity distribution in carbonates and complicates velocity estimations. By assigning characteristic velocity patterns to the observed diagenetic processes, we are able to link sonic velocity to the diagenetic stage of the rock.

Improvement of soft ground deposit s near the coastal areas, delta and black cotton soil areas of the country has been the challenge for infrastructural development. Rapid urban and industrial growth demands more land for further development. In order to meet this demand reclamation and utilization of unsuitable and environmentally affected lands have been taken up. These useless lands for construction have been converted to useful ones by adopting one or more ground improvement techniques. A wide range of techniques have been employed for the load settlement response of weak soil deposits. The field of ground improvement technique is rapidly expanding. It requires lots of investigation and monitoring some of the field problems related to compaction characteristics and feasibility of construction material.

All’interno della nuova filosofia progettuale delle pavimentazioni stradali, basata sulla
valutazione delle prestazioni, che ha permesso un approccio molto più flessibile in termini di
progetto, scelta dei materiali ed esecuzione dei lavori, c’è la forte necessità di sviluppare
metodi veloci e affidabili per la misurazione delle grandezze prestazionali fondamentali (su
tutte la capacità portante e il livello di addensamento) durante le fasi costruttive.
Il Light Weigth Deflectometer è considerato a livello mondiale come lo strumento più adatto
a tale scopo, con enormi potenzialità ancora parzialmente inespresse.
Il seguente lavoro si è basato su una preliminare analisi e caratterizzazione della grandezza
deformativa energy loss e sui vantaggi derivabili da un suo utilizzo come parametro di tipo
prestazionale, attraverso la costruzione di un modello matematico che aiuti, simulandone il
comportamento, a comprenderne le caratteristiche. Nel seguente lavoro le analisi si sono
concentrate su strati di sottofondo e fondazione, quindi su aggregati di tipo naturale e inerti
riciclati.
Lo studio ha approfondito anche l’influenza posseduta dalla rigidezza dei buffer, e
l’importanza di una corretta configurazione dello strumento, in termini di rigidezza degli
smorzatori e quindi di durata dell’impulso di carico trasmesso al terreno (load pulse length).
L’obiettivo finale di questa tesi è stato quello di riuscire a trovare una corrispondenza tra i
parametri di deflessione misurabili dal LWD e il livello di addensamento, limitatamente a
sottofondi e a strati di fondazione costituiti da materiali non legati. Il livello di addensamento
è una misura tradizionale per il controllo prestazionale durante le fasi costruttive, ed è di
fondamentale importanza raggiungere determinati livelli di compattazione per assicurare
durabilità e funzionalità della struttura, minimizzare eventuali cedimenti differenziali e quindi
gli oneri collegati ai lavori di sistemazione e ripristino. Tuttavia i metodi classici per la misura
della densità in sito sono lenti e imprecisi.
Le corrispondenze trovate all’interno di questo studio, tra i valori misurabili mediante il LWD
e il livello di addensamento, potrebbero consentire una valutazione molto più veloce e
affidabile della resistenza alle deformazioni permanenti di strati costituiti da materiali non
legati.

The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballast
layer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the average
seasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weather
situation, Barber’s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessment
of improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber (particle
size 0.2-4 mm) by weight of the total mix, as sub-ballast layer in railway and base layers on roads, recurring to the Superpave mix
design compaction enhanced after computer simulations to evaluate real stresses derived from the rail traffic and climatic conditions.
This article following the assessment of the average seasonal temperatures, involves the characterization of rubberized materials with
attention to crumb rubber properties, designed with dry technology, to enhance the bitumen-rubber and binder-voids ratios. Indirect
tensile strength and water sensitivity tests were applied for the evaluation of its mechanical properties including dynamic complex
modulus at elevated temperature to measure the amount of bitumen absorbed by the rubber. The rubberized mix-results obtained and
the comparison with a conventional HMA (hot mix asphalt) show that these dry rubber bituminous mixtures are particularly effective in
damping vibrations. The purpose of using rubber modifiers in hot mix asphalt to obtain a stiffer-elastic sustainable material has been
achieved for the assessment of its behavior in sub-ballast/base layers.

The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballast layer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the average seasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weather situation, Barber's temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessment of improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber (particle size 0.2-4 mm) by weight of the total mix, as sub-ballast layer in railway and base layers on roads, recurring to the Superpave mix design compaction enhanced after computer simulations to evaluate real stresses derived from the rail traffic and climatic conditions. This article following the assessment of the average seasonal temperatures, involves the characterization of rubberized materials with attention to crumb rubber properties, designed with dry technology, to enhance the bitumen-rubber and binder-voids ratios. Indirect tensile strength and water sensitivity tests were applied for the evaluation of its mechanical properties including dynamic complex modulus at elevated temperature to measure the amount of bitumen absorbed by the rubber. The rubberized mix-results obtained and the comparison with a conventional HMA (hot mix asphalt) show that these dry rubber bituminous mixtures are particularly effective in damping vibrations. The purpose of using rubber modifiers in hot mix asphalt to obtain a stiffer-elastic sustainable material has been achieved for the assessment of its behavior in sub-ballast/base layers. Highlights  An innovative approach for the volumetric design of bituminous mixture with rubber (dry process);  Optimal parameters of temperature and traffic to characterize the mixture for a sub-ballast layer;  Applicability of Barber forecasting model used in the field road, to the railway superstructure;  Performance of the design process for the volumetric analysis of rubberized asphalt;  160 kN and 80 kN, respectively, rail equivalent axle load (R ESAL) were selected comparing sub-ballast vs. road base course solicitations induced for each layer;  Increase of workability and compaction properties decreasing air voids content to 3%-4% of the total mix weight;  Crumb rubber percentage between 1.5% to 2% and a digestion time of 120 min produced the optimal results.

Abstract: This study analyzes the compaction and performance characteristics of asphalt concrete mixtures with aggregate structures that were designed using the Bailey method of aggregate gradation evaluation. Three aggregate types were considered in this study: ...

Solid wastes are all the wastes arising from human and animal activities that are normally solid and are discarded as useless or unwanted. The term solid waste as used in this blog is all- inclusive, encompassing the heterogeneous mass of throwaways from the urban community as well as the more homogeneous accumulation of agricultural, industrial, and mineral wastes. Because of their intrinsic properties, discarded waste materials are often reusable and may be considered as a resource in another setting. Integrated solid waste management is the term applied to all of the activities associated with the management of the community’s waste. The basic goal of integrated solid waste management is to manage community waste in a manner that meets public health and environmental concerns and the public’s desire to reuse and recycle waste material.

The design of an unmodified bituminous mixture and three rubber-aggregate mixtures containing rubber-aggregate by a dry process (RUMAC) was evaluated, using an empirical-analytical approach based on experimental findings obtained in the laboratory with the volumetric mix design by gyratory compaction. A reference dense-graded bituminous sub-ballast mixture (3% of air voids and a bitumen 4% over the total weight of the mix), and three rubberized mixtures by dry process (1,5 to 3% of rubber by total weight and 5-7% of binder) were used applying the Superpave mix-design for a level 3 (high-traffic) design rail lines. The railway tracked section analyzed was a granular layer of 19cm compacted, while for the sub-ballast a thickness of 12cm has been used. To evaluate the effect of increasing the specimen density (as a percent of its theoretical maximum specific gravity), in this article, are illustrated the results obtained after different comparative analysis into the influence of varying the binder-rubber percentages under the sub-ballast layer mix-design. This work demonstrates that rubberized blends containing crumb and ground rubber in bituminous asphalt mixtures behave at least similar or better than conventional asphalt materials. By using the same methodology of volumetric compaction, the densification curves resulting from each mixture have been studied. The purpose is to obtain an optimum empirical parameter multiplier of the number of gyrations necessary to reach the same compaction energy as in conventional mixtures. It has provided some experimental parameters adopting an empirical-analytical method, evaluating the results obtained from the gyratory-compaction of bituminous mixtures with an HMA and rubber-aggregate blends. An extensive integrated research has been carried out to assess the suitability of rubber-modified hot mix asphalt mixtures as a sub-ballast layer in railway underlayment tracked. Design optimization of the mixture was conducted for each mixture and the volumetric properties analyzed. Also, an improved and complete manufacturing process, compaction and curing of these blends are provided. By adopting this increase-parameters of compaction, called " beta " factor, mixtures modified with rubber with uniform densification and workability are obtained that in the conventional mixtures. It is found that considering the usual bearing capacity requirements in rail track, the optimal rubber content is 2% (by weight)