scholarly journals Study of the Optimal Dosage of Celullose Ash as a Contribution Filler in Asphalt Mixtures Based on Its Adhesiveness under Moisture Conditions

2021 ◽  
Vol 13 (2) ◽  
pp. 854
Author(s):  
Diana Movilla-Quesada ◽  
Aitor C. Raposeiras ◽  
Manuel Lagos-Varas ◽  
Osvaldo Muñoz-Cáceres ◽  
Valerio-Carlos Andrés-Valeri ◽  
...  
Keyword(s):  
Latin American ◽  
Critical Concentration ◽  
Resource Scarcity ◽  
Wear Loss ◽  
Optimal Dosage ◽  
Bituminous Mixtures ◽  
Forestry Sector ◽  
Natural Aggregates ◽  
Moisture Conditions ◽  
By Products

Chile is the first Latin American country to begin an “ecological overdraft”, as established by the Global Footprint Network (GFN). This implies that the country’s ecological footprint has exceeded the global average bio-capacity. The consumption of natural aggregates for construction in Chile has grown by around 6.6% in the last year, with around 120 million tons being extracted. Given the above, it is important to seek alternatives that help to minimize the problem of resource scarcity, as well as the recovery of industrial by-products and/or waste. The Chilean forestry sector has also grown in recent years, generating approximately 4000 metric tons of waste in 2018, which was deposited in landfills or disposed of on forest roads. The present research is focused on the reuse and possible recovery of ash from the incineration of cellulose as a filler in bituminous mixtures. We analyze the adhesiveness of the filler/bitumen system in dry and wet states, based on the Cantabro wear loss test. The results obtained show that the limit of the relation between the volumetric concentration and critical concentration (Cv/Cs) is 1 for the addition of ash and that concentrations lower than or equal to this value present controlled losses, with 1.00 being the optimal (Cv/Cs) ratio that allows better behavior against the effect of water.

scholarly journals Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review

2021 ◽  
Vol 13 (5) ◽  
pp. 2756
Author(s):  
Federica Vitale ◽  
Maurizio Nicolella
Keyword(s):  
Building Materials ◽  
Thermal Analyses ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Research Trends ◽  
Mix Design ◽  
Recycled Aggregates ◽  
Design Parameters ◽  
Natural Aggregates ◽  
By Products

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.

scholarly journals Green Concrete: By-Products Utilization and Advanced Approaches

2019 ◽  
Vol 11 (19) ◽  
pp. 5145 ◽  
Author(s):  
Al-Mansour ◽  
Chow ◽  
Feo ◽  
Penna ◽  
Lau
Keyword(s):  
Carbon Footprint ◽  
Review Paper ◽  
Rice Husk Ash ◽  
Sustainable Concrete ◽  
Coarse Aggregates ◽  
Natural Aggregates ◽  
Carbon Dioxide Co2 ◽  
Furnace Slag ◽  
By Products ◽  
Slag Waste

The popularity of concrete has been accompanied with dreadful consumptions that have led to huge carbon footprint in our environment. The exhaustion of natural resources is not yet the problem, but also the energy that is needed for the fabrication of the natural materials, in which this process releases significant amount of carbon dioxide (CO2) emissions into the air. Ordinary Portland Cement (OPC) and natural aggregates, which are the key constituents of concrete, are suggested to be recycled or substituted in order to address the sustainability concern. Here, by-products have been targeted to reduce the carbon footprint, including, but not limited to, fly ash, rice husk ash, silica fume, recycled coarse aggregates, ground granular blast-furnace slag, waste glass, and plastic. Moreover, advanced approaches with an emphasis on sustainability are highlighted, which include the enhancement of the hydration process in cement (calcium-silicate hydrate) and the development of new materials that can be used in concrete (e.g. carbon nanotube). This review paper provides a comprehensive discussion upon the utilization of the reviewed materials, as well as the challenges and the knowledge gaps in producing green and sustainable concrete.

scholarly journals Optimization of Dry Construction Mix with the Addition of Biochar from Reclaimed Rice Straw in the Agro-Industrial Complex

2021 ◽  
Vol 937 (3) ◽  
pp. 032071
Author(s):  
A Smolyanichenko ◽  
Y Shcherban ◽  
S Stel’makh ◽  
A Khalyushev ◽  
Y Zherebtsov
Keyword(s):  
Rice Straw ◽  
Physical And Mechanical Properties ◽  
Average Density ◽  
Optimal Dosage ◽  
Industrial Complex ◽  
Mathematical Planning ◽  
Actual Problem ◽  
Chemical Studies ◽  
Physical And Chemical ◽  
By Products

Abstract Currently, the actual problem is the disposal of various by-products of the agro-industrial complex. This direction practically does not develop, but is solved only by burning them, which leads to air pollution. The article contains physical and chemical studies of a byproduct from rice production, namely rice straw. In the process of recycling rice straw at a temperature of 600°C, biochar is formed, which can be used as a micro-filling additive for dry mortar. Using the method of mathematical planning of the experiment (FFE 2k), optimization was carried out and the optimal composition of the dry mortar was obtained, containing up to 10% of biochar. It has been established that the introduction of biochar in the optimal dosage improves the physical and mechanical properties of the dry mortar in comparison with the control composition on average by: average density – 3%, water absorption – 17%, compressive strength – 12%, tensile strength at bending – 24%, adhesion strength – 55%..

scholarly journals The Influence of the Environment on the Properties of Hybrid Cement-Based Concrete with Steel and Air-Cooled Slags

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1087
Author(s):  
Pavel Martauz ◽  
Vojtěch Václavík ◽  
Branislav Cvopa
Keyword(s):  
Steel Slag ◽  
Blended Cement ◽  
Physical And Mechanical Properties ◽  
Outdoor Environment ◽  
Aqueous Environment ◽  
Test Results ◽  
Mixture Designs ◽  
Natural Aggregates ◽  
By Products

This article presents the results of research that dealt with the development of non-traditional concrete using a hybrid alkali-activated cement. It is concrete based on by-products from a metallurgical plant that replaced 100% of the natural aggregates. Steel slag (CSS, fraction: 0/8 mm) was used as a filler in combination with air-cooled slag (ACBFS, fraction: 8/16 mm and 16/32 mm). Portland blended cement (CEM II/B-S 42.5N) and H-CEMENT were used as binding components in the development of the concrete mixture designs. Both of these cements were produced by Považská cementáreň, a.s., Ladce. Attention was focused on testing the physical and mechanical properties of the developed concretes in various environments. An aqueous environment was selected as the first environment for the placement of test specimens (cubes with 150 mm edges and prisms with dimensions of 100 × 100 × 400 mm3) according to the ČSN EN 206-1 standard and the outdoor environment (August to October). The determination of the cube strength was made after 7, 28, and 90 days, the determination of the flexural and compressive strength was made at the end of the prisms, and the determination of the dynamic modulus of elasticity was made after 28 days on the prisms. The test results of the test specimens, which were placed in two environments, were compared and it was found that, after 90 days, the outdoor environment caused a decrease in the concrete’s strength characteristics when using Portland blended cement (CEM II/ B-S 42.5N) of about 8%; in contrast, when using H-CEMENT, the concrete’s strength increased by about 14%. The use of H-CEMENT and the addition of PUZZOLANIT in the amount of 30% in combination with CEM II/B-S 42.5N in the amount of 70% reduced the decrease in the strength of the concrete after 90 days by about 3%. The research results confirm the suitability of using H-CEMENT and the addition of PUZZOLANIT for the production of concrete based on steel slag (CSS) and air-cooled slag (ACBFS).

scholarly journals Operationalizing Integrated Water Resource Management in Latin America: Insights from Application of the Freshwater Health Index

2021 ◽  
Author(s):  
Maíra Ometto Bezerra ◽  
Derek Vollmer ◽  
Natalia Acero ◽  
Maria Clara Marques ◽  
Diego Restrepo ◽  
...  
Keyword(s):  
Latin America ◽  
Ecosystem Services ◽  
Latin American ◽  
Stakeholder Engagement ◽  
Water Resource Management ◽  
Water Governance ◽  
Resource Scarcity ◽  
Freshwater Ecosystem ◽  
Health Index ◽  
Problems And Solutions

AbstractWater crises in Latin America are more a consequence of poor management than resource scarcity. Addressing water management issues through better coordination, identification of problems and solutions, and agreement on common objectives to operationalize integrated water resources management (IWRM) could greatly improve water governance in the region. Composite indices have great potential to help overcome capacity and information challenges while supporting better IWRM. We applied one such index, the Freshwater Health Index (FHI) in three river basins in Latin America (Alto Mayo, Perú; Bogotá, Colombia; and Guandu, Brazil) to assess freshwater ecosystem vitality, ecosystem services, and the water governance system in place. The approach included convening management agencies, water utilities, planning authorities, local NGOs and industries, community groups and researchers to co-implement the FHI. The results provide detailed information on the ecological integrity of each basin and the sustainability of the ecosystem services being provided. All three basins show very low scores for governance and stakeholder engagement, thus improving both in the region should be a priority. The results also shed light on how the FHI framework can help inform decision-making to improve IWRM implementation by facilitating stakeholder engagement while contributing to coordination, identification of problems and solutions as well as agreement on common objectives. Because implementation of IWRM is part of the solution for the United Nations Sustainable Development Goal (SDG) 6.5 (“By 2030, implement IWRM at all levels, including through transboundary cooperation as appropriate”), our case studies can serve as examples to other Latin American countries to achieve SDG 6.5.

The study of moisture susceptibility for asphalt mixtures containing blast furnace slags

2021 ◽  
Author(s):  
Nicoleta Mariana Ene ◽  
Carmen Răcănel ◽  
Adrian Burlacu
Keyword(s):  
Blast Furnace ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Moisture Susceptibility ◽  
Natural Aggregate ◽  
Important Target ◽  
Indirect Tensile ◽  
Natural Aggregates ◽  
Furnace Slag ◽  
By Products

Nowadays, in the context of increasing traffic, extending road network, and environmental protection, an important target is to develop sustainable roads through the use of by-products derived from various manufacturing processes that can lead to the reduction of environmental degradation. Blast furnace slag is the resulting material during the casting processes of the iron. This is a non-metallic process that is obtained by melting the chemical compounds from the sterile, ash coxe, and the founders. As a result of global research, it has been found that an ecological asphalt mixture (with slags as aggregate) can be used as a pavement layer. However, there are inconveniences related to poor moisture susceptibility. In this context, this paper presents the study of moisture susceptibility of asphalt mixtures with blast furnace slags starting from a basic recipe of AC 31.5 type with natural aggregate and replacing the natural aggregate with slag in different percentages. The paper presents the tests carried out on 15 asphalt mixture recipes with partial and total replacement of natural aggregates with slag artificial aggregates and compared to a classic recipe where 100% natural aggregates were used. The used tests were chosen to characterize the water-related behavior: water absorption and indirect tensile strength test. The results indicate that asphalt mixture with slag aggregates can be a valuable resource in designing asphalt mixtures and satisfactory performance has been achieved.

Nuts by-products: the Latin American contribution

2021 ◽  
pp. 289-315
Author(s):  
Elisa Dufoo-Hurtado ◽  
Ivan Luzardo-Ocampo ◽  
S.M. Ceballos-Duque ◽  
B. Dave Oomah ◽  
Ma. Elena Maldonado-Celis ◽  
...  
Keyword(s):  
Latin American ◽  
By Products ◽  
American Contribution

scholarly journals Bituminous mixtures with low percentage of natural aggregates and rubber modified bitumen with wax

2018 ◽  
Vol 33 ◽  
pp. 91-98 ◽  
Author(s):  
Ángel Vega-Zamanillo ◽  
Pedro Lastra-González ◽  
Miguel A. Calzada-Pérez ◽  
Daniel Castro-Fresno ◽  
Evelio Teijón-López-Zuazo
Keyword(s):  
Modified Bitumen ◽  
Bituminous Mixtures ◽  
Natural Aggregates

Soil deformation observations in a vertisol under field traffic

Soil Research ◽  
1995 ◽  
Vol 33 (5) ◽  
pp. 817 ◽  
Author(s):  
DM Bakker ◽  
RJ Davis
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Grid Method ◽  
Degree Of Saturation ◽  
Soil Deformation ◽  
High Moisture Content ◽  
High Moisture ◽  
Natural Aggregates ◽  
Moisture Conditions ◽  
Horizontal Displacements

A procedure based on the point grid method has been used to measure and visualize soil deformation resulting from tyre loads in a controlled traffic system. Several tests were performed in an irrigated heavy clay soil under various moisture conditions and two different geometries of the wheel tracks, recessed and elevated. This represented normal working conditions and illustrated that significant deformations were occurring. Deformations increased with moisture content and the number of passes. From the point grid displacements, bulk density changes were calculated which corresponded with the measured increases in density obtained from cores. Large displacements were observed when the soil was trafficked at high moisture content with little corresponding increase in bulk density. Soil structural degradation resulting from trafficking this soil at high moisture content should therefore be seen as a different process, such as a change in the orientation of clay particles or porosity of natural aggregates, rather than an increase in bulk density. Significant differences between vertical and horizontal displacements were found for the various tests. Increases in horizontal displacements were contributed to an increase in the degree of saturation. The recessed wheel tracks increased horizontal displacements due to the geometry of the wheel tracks.

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