Construction Materials from Stainless Steel Slags: Technical Aspects, Environmental Benefits, and Economic Opportunities

Construction and demolition wastes (CDW) are generated at a large scale and have a diversified potential in the construction sector. The replacement of natural aggregates (NA) with CDW recycled aggregates (RA) in construction materials, such as mortars, has several environmental benefits, such as the reduction in the natural resources used in these products and simultaneous prevention of waste landfill. Complementarily, CDW have the potential to capture CO2 since some of their components may carbonate, which also contributes to a decrease in global warming potential. The main objective of this research is to evaluate the influence of the exposure of CDW RA to CO2 produced in cement factories and its effect on mortars. Several mortars were developed with a volumetric ratio of 1:4 (cement: aggregate), with NA (reference mortar), CDW RA and CDW RA exposed to high levels of CO2 (CRA). The two types of waste aggregate were incorporated, replacing NA at 50% and 100% (in volume). The mortars with NA and non-carbonated RA and CRA from CDW were analysed, accounting for their performance in the fresh and hardened states in terms of workability, mechanical behaviour and water absorption by capillarity. It was concluded that mortars with CDW (both CRA and non-carbonated RA) generally present a good performance for non-structural purposes, although they suffer a moderate decrease in mechanical performance when NA is replaced with RA. Additionally, small improvements were found in the performance of the aggregates and mortars with CRA subjected to a CO2 curing for a short period (5 h), while a long carbonation period (5 d) led to a decrease in performance, contrary to the results obtained in the literature that indicate a significant increase in such characteristics. This difference could be because the literature focused on made-in-laboratory CDW aggregates, while, in this research, the wastes came from real demolition activities, and were thus older and more heterogeneous.

Download Full-text

Corrosion Behavior of Construction Materials for Intermediate Temperature Steam Electrolysers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.699.596 ◽

2013 ◽

Vol 699 ◽

pp. 596-605 ◽

Cited By ~ 4

Author(s):

Aleksey V. Nikiforov ◽

Irina M. Petrushina ◽

Jens Oluf Jensen ◽

Niels J. Bjerrum

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

Construction Materials ◽

Intermediate Temperature ◽

Aisi 316L ◽

Corrosion Stability ◽

Metal Phosphates ◽

High Corrosion ◽

Steel Aisi ◽

Stainless Steel Aisi

Different corrosion resistant stainless steels, nickel-based alloys, pure nickel, Ta-coated stainless steel (AISI 316L), niobium, platinum and gold rods were evaluated as possible materials for use in the intermediate temperature (200-400 °C) acidic water electrolysers. The corrosion resistance was measured under simulated conditions (molten KH2PO4) corresponding to the proton-conducting solid acids or transition metal phosphates as electrolytes. It was shown that, unlike at temperatures below 200 °C, gold is unstable with respect to corrosion in molten KH2PO4. Platinum demonstrated high corrosion resistance and the anodic and cathodic limits were for the first time found for the electrolyte. Nickel, niobium, Inconel®625, Hastelloy®C-276 and Ta-coated stainless steel (AISI 316L) demonstrated high corrosion stability and can be recommended as construction materials for bipolar plates.

Download Full-text

Impact of Concrete Recycled Materials on some Properties of Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.899.399 ◽

2014 ◽

Vol 899 ◽

pp. 399-402

Author(s):

Miriam Ledererova

Keyword(s):

Construction Materials ◽

Optimal Solution ◽

Environmental Issues ◽

Environmental Benefits ◽

Environmental Aspects ◽

Demolition Waste ◽

Recycled Materials ◽

Basic Characteristics ◽

To Come ◽

Building Demolition

Recycling building demolition waste in addition to environmental benefits is also economically interesting. In addressing the environmental issues it is recommended to give priority to recovery and rational utilization of waste with regard to their basic characteristics before disposal respectively storage. Issue of the use of recycled materials in concrete structures and their disposal in the world and in our longer pays much attention. Use and recycling of construction materials is a great asset for more prospective and progressive methods of construction waste utilizations. The program focused on waste management is therefore necessary to reconcile economic and environmental aspects in order to come to an optimal solution of the issue of waste and environmental protection.

Download Full-text

Evaluation of the Feasibility of Recycled Concrete Aggregate for Producing Structural Concrete

E3S Web of Conferences ◽

10.1051/e3sconf/202022001098 ◽

2020 ◽

Vol 220 ◽

pp. 01098

Author(s):

Mohammad Tabrez Ali ◽

Ibadur Rahman ◽

Nirendra Dev ◽

Priyanka Singh

Keyword(s):

Compressive Strength ◽

Construction Materials ◽

Recycled Concrete ◽

Environmental Benefits ◽

Mix Design ◽

Concrete Aggregate ◽

Recycled Concrete Aggregate ◽

Structural Concrete ◽

Average Value ◽

Maximum Compressive Strength

When sustainability has become a primary measure of the selection of the building materials in the construction industry over the past decades, researchers all around the world have been looking upon for alternatives to reduce the overall environmental impact of the construction materials while not compromising the strength and durability. The factors like manufacturing, reusability, recyclability, disposal etc, are the criteria of utmost attention affecting the overall life cycle impact of the construction materials. In this prospect the Recycled Concrete Aggregate (RCA) has shown up as an exceptionally viable contender for the manufacturing of concrete with several environmental benefits over the Natural Aggregate (NA) and has already been identified by industry and several government agencies across the globe. The efficient material use of RCA can potentially deliver an inferior though competent concrete in comparison to the NA while averring the criteria of sustenance. The present study delves into the calculation of the proportion of the RCA in a mix design for achieving maximum compressive strength. The experimental setup constituted the casting of concrete cubes of control mix design of M40 grade with proportions of RCA varying from 0-100 percent spread over a space of 10% with NA which were later put to tests. The thorough investigation on the casted concrete cubes lead to the conclusion that the mix design with 50% proportion of RCA in addition to 50% proportion of NA delivered the maximum compressive strength, an average value of 8.23% higher than that of the normal concrete and the highest Rebound Number, an average value of 53.92 for the M40 grade concrete thereby showcasing the feasibility of producing structural concrete with RCA. The results are asserted to be governed by the better bonding between the RCA and NA and due to the significant increase in the water retention capacity by the provision of RCA in the mix.

Download Full-text

THE CLEANABILITY OF MATERIALS IN CONTACT WITH DAIRY PRODUCTS1

Journal of Milk and Food Technology ◽

10.4315/0022-2747-21.3.68 ◽

1958 ◽

Vol 21 (3) ◽

pp. 68-72 ◽

Cited By ~ 6

Author(s):

G. L. Hays ◽

J. D. Burroughs ◽

D. H. Johns

Keyword(s):

Stainless Steel ◽

Dairy Products ◽

Construction Materials ◽

Complete Removal ◽

Radioactive Tracer ◽

E Coli ◽

Tracer Techniques ◽

Equipment Construction ◽

Dairy Equipment

The removal of air dried soil (dairy products contaminated with E. coli) from the surface of disks of several possible dairy equipment construction materials was determined by both radioactive tracer techniques and bacteriological methods. Both methods showed that cleaning the disks with any of the four types of cleaning compounds effected essentially complete removal of the contaminating soil from the surface of the molded plastics and various finishes of stainless steel which were tested.

Download Full-text

Forest Products Utilization Within a Circular Bioeconomy

Forest Products Journal ◽

10.13073/0015-7473.70.1.4 ◽

2020 ◽

Vol 70 (1) ◽

pp. 4-9

Author(s):

Richard F. Baldwin

Keyword(s):

Public Awareness ◽

Construction Material ◽

Construction Materials ◽

Forest Products ◽

Environmental Benefits ◽

Raw Material ◽

Wood Structures ◽

Processing Technologies ◽

Diverse Species ◽

Wood Construction

Abstract The advent of tall wood structures in North America is heightening a public awareness that forest products, designed for higher and better uses, will lead to enhanced environmental benefits within the Circular Bioeconomy. The application of these newer wood-based processing technologies and their resulting products, in place of completive products such as concrete, steel and other non-wood construction materials, will redefine and expand the advantages that wood has as a construction material. Further, the growing capability to use small logs, and diverse species, as raw material for the newer generation of forest products will magnify the carbon sequestration benefits from the working forest. A recipe of getting more benefits and improved utilization from the working forest is identified and described, while focusing on the means and methods of obtaining these benefits.

Download Full-text

High Temperature Service Experience and Failure Analysis of some Heat Resistant Stainless Steels

Materials Science Forum ◽

10.4028/www.scientific.net/msf.696.120 ◽

2011 ◽

Vol 696 ◽

pp. 120-125

Author(s):

Pascale Sotto Vangeli ◽

Bo Ivarsson

Keyword(s):

Stainless Steel ◽

High Temperature ◽

Construction Material ◽

Construction Materials ◽

Research Centre ◽

Materials Selection ◽

Charcoal Production ◽

Heat Resistant ◽

Number Of Factors ◽

Work Done

Construction materials are exposed to aggressive high temperature environments and it is important for materials selection to identify the failure mechanism of corroded components. This paper describes work done at Outokumpu Avesta Research Centre, Sweden to diagnose the high temperature problems of two different stainless steel components. It describes how the severity of the corrosion was the result of interaction of a number of factors, and outlines the measures taken to alleviate the problems. The discussion highlights how heavy carburization could be a problem for the heat resistant grade 310S, used as construction material for tanks in charcoal production and how Cl-containing flue gases heavily corrode stainless steel.

Download Full-text

Evaluation of Leachate Recirculation Effect on the Acceleration of Waste Mineralization Process by Using a Coupled Numerical Model

Advances in Civil Engineering ◽

10.1155/2021/8832085 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Hailong Liu ◽

Zhen Huyan ◽

Chunyi Cui ◽

Xiang Luo ◽

Xingyao Jiang

Keyword(s):

Landfill Gas ◽

Construction Materials ◽

Coupled Model ◽

Environmental Benefits ◽

Leachate Recirculation ◽

Mineralization Process ◽

Kitchen Waste ◽

Gas Generation ◽

Leachate Treatment ◽

Transportation Facilities

Accelerating the waste mineralization is of great significance to control the settlement of transportation facilities nearby landfills. Mineralized waste can also be used as road construction materials to recycle waste resources and reduce the construction cost of transportation facilities. A biochem-hydro-mechanical-solute migration-coupled model for describing complex interactions in landfills with high kitchen waste content has been developed. The proposed model can consider large leachate production and landfill gas entrapment due to the fast degradation of kitchen waste. The quantitative effects of three leachate recirculation conditions are investigated in this article via a typical landfill cell. According to the simulation results, introducing methanogen into landfills with leachate recirculation can relieve acidification caused by fast hydrolysis of kitchen waste and speed up the mineralization process of landfills with high kitchen waste content significantly. Furthermore, landfill gas generation potential loss and fast degradation compression should be considered in the implementation of leachate recirculation in landfills with high kitchen waste content, which helps to maintain the operation of transportation facilities nearby landfills and improve the economic and environmental benefits of leachate treatment.

Download Full-text

Comparison of Corrosion Behavior of the Austenitic Stainless Steel 316 L in Static and Flowing Liquid Lead

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4049719 ◽

2021 ◽

Vol 7 (2) ◽

Author(s):

Lucia Rozumová ◽

Lukáš Košek ◽

Jan Vít ◽

Anna Hojná ◽

Patricie Halodová

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Focused Ion Beam ◽

Ion Beam ◽

Construction Materials ◽

Static Condition ◽

Oxide Thickness ◽

Liquid Lead ◽

Flowing Liquid ◽

Nuclear Systems

Abstract Development of liquid lead cooled nuclear systems requires consideration of compatibility issues with the construction materials. In order to understand the corrosion or passivation behavior of the 316 L austenitic stainless steel, the steel specimens were exposed for 1000 h in liquid lead with 1 × 10−7 wt % oxygen level at 480 °C in static and flowing (velocity 1.6 m/s) conditions. Post-test microscopy investigation using scanning electron microscope with focused ion beam (FIB) was performed and it demonstrated significant differences in the formation of thin oxide layers in the two conditions. Maximum oxide thickness was 2 μm in the static lead (Pb) and less than 0.1 μm in the flowing Pb. In the static condition, oxide scale was not continuous and local corrosion attack was indicated; but in flowing condition the oxide layer was continuous without any corrosion attacks.

Download Full-text

Formulation of Alkali-Activated Slag Binder Destined for Use in Developing Countries

Applied Sciences ◽

10.3390/app10249088 ◽

2020 ◽

Vol 10 (24) ◽

pp. 9088

Author(s):

Nabil Bella ◽

Edwin Gudiel ◽

Lourdes Soriano ◽

Alba Font ◽

María Victoria Borrachero ◽

...

Keyword(s):

Developing Countries ◽

Portland Cement ◽

Construction Materials ◽

Environmental Benefits ◽

Economic Study ◽

Cement Production ◽

Golden Opportunity ◽

Activated Slag ◽

Furnace Slag ◽

Alkali Activated

Worldwide cement production is around 4.2 billion tons, and the fabrication of one ton of ordinary Portland cement emits around 900 kg of CO2. Blast furnace slag (BFS) is a byproduct used to produce alkali-activated materials (AAM). BFS production was estimated at about 350 million tons in 2018, and the BFS reuse rate in construction materials of developing countries is low. AAM can reduce CO2 emissions in relation to Portland cement materials: Its use in construction would be a golden opportunity for developing countries in forthcoming decades. The present research aims to formulate AAM destined for future applications in developing countries. Two activators were used: NaOH, Na2CO3, and a mixture of both. The results showed that compressive strengths within the 42–56 MPa range after 28 curing days were obtained for the Na2CO3-activated mortars. The characterization analysis confirmed the presence of hydrotalcite, carbonated phases, CSH and CASH. The economic study showed that Na2CO3 was the cheapest activator in terms of the relative cost per ton and MPa of manufactured mortars. Finally, the environmental benefits of mortars based on this reagent were evidenced, and, in terms of kgCO2 emissions per ton and MPa, the mortars with Na2CO3 yielded 50% lower values than with NaOH.

Download Full-text