scholarly journals Engineering Characteristics and Environmental Risks of Utilizing Recycled Aluminum Salt Slag and Recycled Concrete as a Sustainable Geomaterial

2021 ◽  
Vol 13 (19) ◽  
pp. 10633
Author(s):  
Youli Lin ◽  
Farshid Maghool ◽  
Arul Arulrajah ◽  
Suksun Horpibulsuk
Keyword(s):  
Los Angeles ◽  
Particle Density ◽  
Construction Material ◽  
Environmental Risks ◽  
Recycled Concrete ◽  
Aluminum Salt ◽  
Concrete Aggregate ◽  
Chemical Test ◽  
Engineering Characteristics ◽  
Salt Slag

Recycled aluminum salt slag (RASS) is an industrial by-product generated from the melting of white dross and aluminum scraps during the secondary smelter process. Insufficient knowledge in the aspects of engineering characteristics, and the environmental risks associated with RASS, is the primary barrier to the utilization of RASS as a substitute material for natural quarry materials in the field of geotechnical construction. In this research, comprehensive geotechnical and environmental engineering tests were conducted to evaluate the feasibility of utilizing RASS as a sustainable geomaterial. This was undertaken by comparing the laboratory testing results for RASS with a well-known recycled material, namely recycled concrete aggregate (RCA), and the relevant specifications set forth by the local road authority. The geotechnical engineering assessment included particle size distribution, flakiness index, organic content, pH, particle density, water absorption, modified Proctor compaction, aggregate impact value, Los Angeles (LA) abrasion, hydraulic conductivity, and California bearing ratio (CBR). The CBR results of the RASS samples satisfied the minimum CBR value (>80%) for usage as pavement subbase material in road construction. In addition, the repeated load triaxial (RLT) tests were carried out on the RASS samples to assess the response of the RASS under cyclic loading conditions. Furthermore, a range of chemical tests, consisting of leaching and polycyclic aromatic hydrocarbon tests, were also performed on the RASS to address the environmental concerns. Comparing the chemical test results with the environmental protection authorities’ guidelines provided satisfactory evidence that RASS will not pose any environmental and health issues throughout its service life as a geotechnical construction material.

scholarly journals Geotechnical Properties of Anthropogenic Soils in Road Engineering

2020 ◽  
Vol 12 (12) ◽  
pp. 4843
Author(s):  
Andrzej Głuchowski ◽  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Raimondas Šadzevičius ◽  
Wojciech Sas
Keyword(s):  
Cyclic Loading ◽  
Bearing Capacity ◽  
Construction Material ◽  
Bottom Ash ◽  
Field Tests ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Test Results ◽  
Anthropogenic Soils ◽  
Road Engineering

The construction of a roads network consumes high amounts of materials. The road materials are required to fulfill high standards like bearing capacity and low settlement susceptibility due to cyclic loading. Therefore, crushed aggregates are the primary subbase construction material. The material-intensity of road engineering leads to depletion of natural resources, and to avoid it, the alternative recycled materials are required to be applied to achieve sustainable development. The anthropogenic soils (AS), which are defined as man-made unbound aggregates, are the response to these requirements. For the successful application of the AS, a series of geotechnical laboratory and field tests were conducted. In this article, we present the set of 58 test results, including California Bearing Ratio (CBR) bearing capacity tests, oedometric tests, and cyclic CBR tests, to characterize the behavior of three AS types and to compare its reaction with natural aggregate (NA). The AS tested in this study are recycled concrete aggregate (RCA), fly ash and bottom ash mix (BS), and blast furnace slag (BFS). The results of the tests show that the AS has similar characteristics to NA, and in some cases, like compression characteristic, RCA and BFS behave a stiffer response to cyclic loading. The test results and analysis presented here extend the knowledge about AS compressibility and AS response to cyclic loading.

scholarly journals Los Angeles index and water absorption capacity of crushed aggregates

2020 ◽  
Vol 15 (1) ◽  
pp. 65-78
Author(s):  
Mohammed Abed ◽  
Rita Nemes
Keyword(s):  
Los Angeles ◽  
Water Absorption ◽  
High Performance Concrete ◽  
Absorption Capacity ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Aggregate Concrete ◽  
Crushed Aggregate

Abstract The mechanical and physical properties of the crushed aggregate have been studied. The properties of crushed aggregate, which produced from recycled aggregate concrete is not discussed in the literature yet despite it could be a choice in some circumstances like in case of demolishing the structures that already constructed by recycled aggregate concrete. Twenty-two types of self-compacting high-performance concrete made by coarse natural aggregate and coarse recycle concrete aggregate have been crushed and their properties have been studied. The main findings of the present study that, the Los Angeles index and water absorption of crushed aggregate is affected by the coarse recycled concrete aggregate dosage in its parent concrete, as well as, incorporating cement replacing materials in parent concrete help to enhance the abrasion resistance of crushed aggregate.

scholarly journals Estimation of Recycled Concrete Aggregate’s Water Permeability Coefficient as Earth Construction Material with the Application of an Analytical Method

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2920 ◽  
Author(s):  
Wojciech Sas ◽  
Justyna Dzięcioł ◽  
Andrzej Głuchowski
Keyword(s):  
Permeability Coefficient ◽  
Construction Material ◽  
Recycled Concrete ◽  
Design Stage ◽  
Water Volume ◽  
Physical Parameters ◽  
Concrete Aggregate ◽  
Earth Construction ◽  
Water Permeability Coefficient ◽  
Volume Measurements

Creating models based on empirical data and their statistical measurements have been used for a long time in the economic sciences. Increasingly, these methods are used in the technical sciences, such as construction and geotechnical engineering. This allows for reducing the costs of geotechnical research at the design stage. This article presents the research carried out on Recycled Concrete Aggregate (RCA) material with is reclaimed crushed concrete rubble. Permeability tests were carried out using the constant head method. Tests were conducted on blends of RCA with the following particle size ranges: 0.02–16 mm, 0.05–16 mm, 0.1–16 mm, and 0.2–16 mm. The gradients used during the tests were between 0.2 to 0.83, which corresponds to gradients encountered in earth construction and are below the critical gradient. Directly from the tests, the flux velocity for the range of tested gradients were calculated based on filtered water volume measurements. The values of the permeability coefficient (k) were then recalculated. Finally, statistical methods were used to determine which physical parameters of the tested material affect the permeability coefficient. The physical parameters selected from the statistical analysis were used to create a model describing the phenomenon. The model can be used to determine the permeability coefficient for a mixed RCA material. The article ends with conclusions and proposals concerning the use of models and the limits of their applicability.

scholarly journals Utilisation of Recycled Aggregate as Coarse Aggregate in Concrete

2009 ◽  
Vol 1 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Yong P.C. ◽  
Teo D.C.L
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Material ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Normal Concrete ◽  
Aggregate Concrete

In this rapid industrialised world, recycling construction material plays an important role to preserve the natural resources. In this research, recycled concrete aggregates (RCA) from site-tested concrete specimens were used. These consist of 28-days concrete cubes after compression test obtained from a local construction site. These concrete cubes are crushed to suitable size and reused as recycled coarse aggregate. The amount of recycled concrete aggregate used in this research is approximately 200 kg. Many researchers state that recycled aggregates are only suitable for non-structural concrete application. This research, however, shows that the recycled aggregates that are obtained from site-tested concrete specimen make good quality concrete. The compressive strength of recycled aggregate concrete (RAC) is found to be higher than the compressive strength of normal concrete. Recycled aggregate concrete is in close proximity to normal concrete in terms of split tensile strength, flexural strength and wet density. The slump of recycled aggregate concrete is low and that can be improved by using saturated surface dry (SSD) coarse aggregate.

DURABILITY STUDIES OF PQC MIX INCORPORATING RECYCLED CONCRETE AGGREGATE AND MINERAL ADMIXTURES

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
G. D. Ransinchung R. N. ◽  
Abhishek Jindal
Keyword(s):  
Construction Material ◽  
Chloride Ion ◽  
Recycled Concrete ◽  
Mineral Admixtures ◽  
Concrete Aggregate ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Durability Properties ◽  
Concrete Production ◽  
Natural Aggregates

Concrete as known globally is the most widely used construction material in all type of construction works. Recycled concrete aggregates have been eyed as a viable option for part replacement of natural coarse aggregates for concrete production by researchers for quite some time. However, their tendency to bring down the property parameters of new concrete makes it very important to investigate the extent of variation in durability properties of fresh concrete incorporating recycled concrete aggregates. Mineral admixtures are believed to improve the durability and mechanical aspects of concretes. This study makes an effort to understand the effects of incorporating recycled concrete aggregates and different mineral admixtures on durability aspects of pavement quality concrete mixes. In order to investigate the same, recycled concrete aggregates were used along with mineral admixtures in different proportions to study the variation in properties. Concrete mixes prepared with natural aggregates, recycled concrete aggregates and mixes containing recycled concrete aggregates and mineral admixtures were prepared and tested for variations in their durability properties. Laboratory investigations revealed that incorporating mineral admixtures does improves the durability aspects of pavement quality concrete having recycled concrete aggregates. Reduction in values for water absorption, sorptivity coefficients and chloride ion concentrations supported better durability aspects for mixes prepared with recycled concrete aggregates incorporating mineral admixtures.

Wastewater treatment and risk assessment in ocean outfall evaluations

1998 ◽  
Vol 38 (10) ◽  
pp. 309-316
Author(s):  
William F. Garber
Keyword(s):  
Wastewater Treatment ◽  
Los Angeles ◽  
Energy Use ◽  
Epidemiological Studies ◽  
Environmental Risks ◽  
Advanced Treatment ◽  
Negative Effect ◽  
Ocean Outfall ◽  
Treatment And Disposal ◽  
The City

Past evaluations of the success of wastewater treatment and submarine outfall placement and operation have considered only a limited number of parameters affecting the marine and onshore environments. Important questions regarding the best allocation of available funds have not been adequately addressed. The relative contamination of the sea from airborne and landwash contaminants has not been considered. Neither has the increased air pollution deriving from the energy required for advanced treatment. Similarly, regular epidemiological studies to evaluate actual changes in morbidity arising from drastic changes in treatment and disposal have not been made prior to very large committments of funds. Most importantly, little attention has been given to the relative ranking of all environmental risks within a catchment area. The net result is that, when all factors are considered, the very large expenditures and increased energy use for sanitary wastewater treatment and outfall disposal will have a net negative effect on the physical and societal environment. The City of Los Angeles and the Los Angeles Metropolitan area can be used to illustrate this probability.

scholarly journals Review of the relationship between aggregates geology and Los Angeles and micro-Deval tests

2021 ◽  
Vol 80 (3) ◽  
pp. 1963-1980
Author(s):  
Solomon Adomako ◽  
Christian John Engelsen ◽  
Rein Terje Thorstensen ◽  
Diego Maria Barbieri
Keyword(s):  
Los Angeles ◽  
Crystal Size ◽  
Grain Shape ◽  
Mechanical Performance ◽  
Pore Space ◽  
Construction Material ◽  
Engineering Properties ◽  
Coarse Grained ◽  
The Impact ◽  
The Relationship

AbstractRock aggregates constitute the enormous volume of inert construction material used around the globe. The petrologic description as igneous, sedimentary, and metamorphic types establishes the intrinsic formation pattern of the parent rock. The engineering properties of these rocks vary due to the differences in the transformation process (e.g. hydrothermal deposits) and weathering effect. The two most common mechanical tests used to investigate the performance of aggregates are the Los Angeles (LA) and micro-Deval (MD) tests. This study reviewed the geological parameters (including mineralogy, grain and crystal size, grain shape, and porosity) and the relationship to Los Angeles and micro-Deval tests. It was found that high content of primary minerals in rocks (e.g. quartz and feldspar) is a significant parameter for performance evaluation. Traces of secondary and accessory minerals also affect the performance of rocks, although in many cases it is based on the percentage. Furthermore, some studies showed that the effect of mineralogic composition on mechanical strength is not sufficient to draw final conclusions of mechanical performance; therefore, the impact of other textural characteristics should be considered. The disposition of grain size and crystal size (e.g. as result of lithification) showed that rocks composed of fine-grain textural composition of ≤ 1 mm enhanced fragmentation and wear resistance than medium and coarse grained (≥ 1 mm). The effect of grain shape was based on convex and concave shapes and flat and elongated apexes of tested samples. The equidimensional form descriptor of rocks somehow improved resistance to impact from LA than highly flat and elongated particles. Lastly, the distribution of pore space investigated by means of the saturation method mostly showed moderate (R = 0.50) to strong (R = 0.90) and positive correlations to LA and MD tests.

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