•A Techno-economic analysis of a mechanical reclamation process for the waste foundry sand is conducted.•A multi-stakeholder analysis is presented for the new foundry sand ecosystem that adopts the ...proposed reclamation technology.•A plant size of 1 ton h−1 showed promising potential with NPV (₹57.21 million or $ 0.76 million), IRR (29.78%), and BCR (5.48).•A foundry that uses the reclaimed sand, instead of the fresh one, showed an annual saving of 10.80 million ($0.144 million).
This article presents a holistic approach to promote waste foundry sand (WFS) reclamation in India by designing a framework for a multistakeholder approach that combines resources, technology, and potential market. The scale of WFS generation and dumping is estimated based on a survey, and a solution is proposed that integrates WFS collection and sand reclamation technology for foundry sand ecosystem development. The study further examined the economic feasibility of a mechanical reclamation process for WFS, using indicators such as net present value (NPV), internal rate of return (IRR), discounted payback period (DPBP), and benefit-cost ratio (BCR). A sand reclamation plant of 1 ton h−1 capacity showed promising economics, and the NPV, IRR, DPBP, and BCR were found to be ₹57.21 million ($0.76 million), 29.78%, 2.82 years, and 5.48, respectively. All the operating, manpower, raw material, and utility costs reasonably influence the economics of the reclamation process. In parallel, sensitivity and uncertainty analyses were carried out using a Monte Carlo simulation to understand the influence of the above-mentioned indicators on the economics of the process. This uncertainty analysis predicted an average NPV of ₹56.55 ± 2 million ($0.75 ± 0.027 million). The castings made up of reclaimed sand appeared to be cost competitive at the reclaimed sand price in the range of ₹1000–2000 ton−1 ($13.33–26.67 ton−1). Overall, the designed framework appears to encourage reduction in WFS disposal and promotion of reclaimed sand in Indian foundries. Policy interventions are suggested to promote the proposed solution in its initial phase.
Display omitted
Concrete is a composite material that is commonly used in the construction industry. It will certainly be exposed to fires of varying intensities when used in buildings and industries. The major goal ...of this article was to look into the influence of mineral additions such as foundry sand and marble dust on the residual characteristics of concrete. To examine the behavior of residual characteristics of concrete after fire exposure, marble dust was substituted for cement and fine sand was substituted for foundry sand in varying amounts ranging from 0% to 20%. It aided in the better disposal of waste material so that it might be used as an addition. The purpose of the experiment was to see how increased temperatures affected residual properties of concrete, including flexural strength, compressive strength, tensile strength, static as well as dynamic elastic modulus, water absorption, mass loss, and ultrasonic pulse velocity. At temperatures of 200 °C, 400 °C, 600 °C, 800 °C, and 1000 °C, the typical fire exposure behavior of concrete was investigated. The effects of two cooling techniques, annealing and quenching, on the residual properties of concrete after exposure to high temperatures were investigated in this study. Replacement of up to 10% of the cement with marble dust and fine sand with foundry sand when concrete is exposed to temperatures up to 400 °C does not influence the behavior of concrete. At temperatures above 400 °C, however, the breakdown of concrete, which includes marble dust and foundry sand, causes a rapid deterioration in the residual properties of concrete, primarily for replacement of more than 10%.
Purpose
In the construction sector, river sand has turned into a costly material due to various reasons. In the current study, used foundry sand (UFS) and spent garnet sand (SGS) are used as a ...partial and full replacement to sand in concrete production.
Design/methodology/approach
The objective of the work is to develop non-conventional concrete by replacing river sand with a combination of UFS (constant 20Wt.% replacement) and SGS at various percentages (20, 40, 60 and 80 Wt.%).
Findings
Compared to conventional concrete, the 28 days compressive strength of non-conventional concrete (with UFS at 20% and spent garnet sand at 20%, 40% and 60% were 8.12%, 6.77% and 0.83% higher, respectively. The 28 days split tensile strength of non-conventional concrete (UFS at 20% and SGS at 20 and 40%) were 32.2% and 51.6% higher, respectively.
Research limitations/implications
It can be concluded that 60 Wt.% of river sand can be combined replaced with 20 Wt.% UFS and 40 Wt.% SGS to produce good quality concrete whose properties are on par with conventional concrete.
Practical implications
The results showed that combined SGS and UFS can be used as a partial replacement of river sand in the manufacturing of concrete that is used in all the applications of construction sector such as buildings, bridges, dams, etc. and non-structural applications such as drainpipes, kerbs, etc.
Social implications
Disposal of industrial by-product wastes such as SGS and UFS affects the environment. A sincere attempt is made to use the same as partial replacement of river sand.
Originality/value
Based on the literature study, no work is carried out in replacing the river sand combined with SGS and UFS in concrete.
This paper presents an extensive critical review of various properties of self-compacting concrete made with industrial by-products. The construction industry has recognized the worth of limited ...available natural resource like river sand, which is extensively used for the production of self-compacting concrete. Also, the management and disposal of the industrial by-products has become a major challenge globally. Sustainable production thus comes into picture by incorporating the industrial by-products in self-compacting concrete to benefit the environment as well as concrete technology. This paper highlights the use of industrial by-products like waste foundry sand, coal bottom ash, waste tire rubber, copper slag, and waste glass as fine aggregate replacement in the development of green self-compacting concrete. It discusses in detail, the physical and chemical properties of industrial by-products used in self-compacting concrete. It comprehensively reviews the effect of using by-products on the fresh, strength and durability properties of self-compacting concrete. Based on the reviewed literature, critical analysis has been carried out, and the future scope of work is addressed. These industrial by-products have a great potential to be utilized in self-compacting concrete, leading to sustainable development.
•Critical review of self-compacting concrete made with by-products is presented.•Foundry sand, coal bottom ash, tire rubber, copper slag and waste glass are used.•Effect of by-products on properties of self-compacting concrete is presented.•Directions for future research studies on the use of by-products are suggested.
•Characterisation of waste foundry sand using XRD, TGA-DTG and SEM.•Utilisation of waste foundry sand for natural fine aggregate replacement.•Fresh and hardened properties of self-compacting concrete ...containing waste foundry sand.•Water permeability and sorptivity using autoclam apparatus.
Large amounts of waste foundry sand (WFS) is being generated worldwide every year and it is necessary to re-use it for valuable cause. WFS is reported suitable up to a certain extent for replacement of fine aggregate in concrete. Answering the doubt on the issue of workability and durability properties can enhance its potential use. This study investigates the usability of waste foundry sand in self-compacting concrete (SCC). Fine aggregate was replaced with WFS with ratios ranging from 0 to 40%. The properties of WFS were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray fluorescence (XRF) methods. The effect of WFS was observed for the workability, mechanical behaviour and durability of the resulting SCC. The WFS showed distinct effects on workability with each level of replacement. At 90 days, SCC containing 10% WFS showed better mechanical and durability properties as compared to the control mix. Beyond 10% replacement level, strength and durability of concrete specimens started to show degradation. But WFS was observed as an excellent alternative for reducing the segregation especially in SCC. SCC with up to 20% WFS also showed acceptable levels of key performance parameters.
The use of waste materials in the building industry is a major challenge for eco-efficient construction. Brazil generates more than 3 million tons of waste foundry sand (WFS) annually, making it one ...of the largest industrial wastes produced in the country. This work proposes the use of WFS in two novel ways: in conventional concrete by WFS calcination, and in dry-mix concrete for the production of concrete blocks. For the conventional mixture study, mortars with 0, 50 and 100% replacement of natural sand by WFS and calcined WFS (CFS) were produced. The fresh state properties, volumetric variation, cement hydration and 28-days compressive strength of the mortars were evaluated. For the dry-mix concrete study, compositions with two densities (2.20 and 2.25 g/cm3), three cement contents and 0, 50 and 100% WFS in natural sand replacement were produced in the laboratory. Furthermore, concrete blocks of different strength ranges and 0 and 100% WFS in natural sand replacement were produced in a concrete block manufacturing plant for full-scale testing. The results showed that the use of WFS led to reductions in flowability and compressive strength of the mortars, but did not cause expansion as initially expected. In contrast, the use of up to 100% CFS resulted in mortars with flowability and compressive strength similar to those of the reference. WFS calcination removed the pulverized coal and may have formed pozzolanic phases in the clay material. As a result, the CFS presented performance similar to that of natural sand. In dry-mix concrete, the laboratory results showed that the use of 100% WFS resulted in similar strengths to the reference for concretes of up to 20 MPa. Finally, full-scale tests showed that it was possible to produce concrete blocks with 100% WFS and strengths compatible to the reference.
•Calcination at 900 °C removed the pulverized coal of the waste foundry sand (WFS).•Calcination may have formed pozzolanic phases in the bentonite present in WFS.•WFS showed performance similar to that of natural sand.•Dry-mix concretes with 100% WFS showed up to 96% of the reference strength.•Concrete blocks with 100% WFS and satisfactory strength were produced.
Display omitted
•Need of use of waste foundry sand (WFS) in concrete.•Material properties of WFS.•WFS shows enhanced mechanical performance of concrete.•Durability of concrete enhanced with ...incorporation of WFS up to an optimum level.
Concrete is the most extensively used construction material in the world, second to water. Increasing rate of urbanization and industrialization has lead to over exploitation of natural resources such as river sand and gravels, which is giving rise to sustainability issues. It has now become imperative to look for alternatives of constituent materials of concrete. Waste foundry sand, a by-product of ferrous and non ferrous metal casting industries is one such promising material which can be used as an alternative to natural sand in concrete. In last few decades, several studies have been conducted to investigate the effect of addition of waste foundry sand as partial and complete replacement of regular sand in concrete. It has been found suitable to be used as partial replacement of sand in structural grade concrete. A number of properties have been reviewed in the current paper, the results observed from the various studies depict that replacement of foundry sand to a certain extent enhance the durability as well as strength properties of the concrete but simultaneously decreases the slump value with the increase of replacement level of waste foundry sand.
Waste foundry sand (WFS) is the by-product of the foundry industry. Utilizing it in the construction industry will protect the environment and its natural resources, and enable sustainable ...construction. WFS was employed in this research as a fractional substitution of natural sand by 0%, 10%, 20%, 30%, and 40% in concrete. Several tests, including workability, compressive strength (CS), splitting tensile strength (STS), and flexural strength (FS), ultrasonic pulse velocity (USPV), Schmidt rebound hammer number (RHN), and residual compressive strengths (RCS) tests were performed to understand the behavior of concrete before and after exposure to elevated temperatures. Test findings showed that the strength characteristics were increased by including WFS at all the phases. For a substitute rate of 30%, the maximum compressive, splitting tensile, and flexural strength were observed. Replacement with WFS enhanced the 28-day compressive, splitting tensile, and flexural strength by 7.82%, 9.87%, and 10.35%, respectively at a 30% replacement level, and showed continuous improvement until the age of 91 days. The RCS of foundry sand concrete after one month of air cooling at ambient temperature after exposing to 300 °C, 400 °C, 500 °C, 600 °C, 700 °C, and 800 °C was found to be in the range of 67.50% to 71.00%, 57.50% to 61.50%, 49.00% to 51.50%, 38% to 41%, 31% to 35% and 26% to 31.5% of unheated compressive strength values for 0% to 40% replacement of WFS, respectively. The RCS decreases with increasing temperature; however, with increasing WFS, the RCS was enhanced in comparison to the control samples. In addition, the replacement of 30% yielded excellent outcomes. Hence, this study provides a sustainable construction material that will preserve the Earth's natural resources and provide a best use of WFS.
PDF