Waste foundry sand (WFS) is a by-product of the metal casting process, which constitutes a sustainable solution as a replacement for natural sand (NS) in the production of concrete. This article ...provides an overview of two types of WFS, along with their physical and chemical properties. The present research highlights the potential applications of WFS in mortars, concrete, and self-compacting concrete (SCC). In addition to examining the influence of WFS substitution on workability, mechanical properties, and durability. The literature consulted indicates that the workability, mechanical properties, and durability of mortar, concrete, and SCC may be affected when increasing the substitution of NS with WFS. However, in some cases, WFS can offer comparable or improved mechanical and durability properties to NS. It has been observed that in some studies, impurities in the form of clay particles, dust, and phenolic resins of the WFS particles are the reason for the resulting decrease reported in workability, mechanical properties, and durability. Few studies report durability in terms of ultrasonic pulse velocity (UPV), freeze-thaw resistance, abrasion, chloride penetration, and sulphate resistance, which is a research gap that should be addressed. Moreover, the use of WFS is a viable alternative to NS, leading to a more sustainable and environmentally friendly approach for the construction industry.
•Waste foundry sand is a viable alternative as a replacement for natural sand.•The binder traces in waste foundry sand particles cause workability and strength loss.•A decrease in workability and compressive strength is observed when waste foundry sand replacement contents exceed 20%.•The durability of concrete made with waste foundry sand is adequate.•The incorporation of waste foundry sand results in material cost savings of 7.5–10%.
Environmental issues were ascended in construction field owing to the rapid growth in population, over utilization and utilization of non-renewable resources. It is necessary to look for alternatives ...of waste disposal and relevant constituent materials for concrete to impart sustainable development in construction industry. To effectively reduce the utilization of natural occurring fine aggregate in concrete, the biologically treated discarded foundry sand (WFS) was used as a replacement material in this investigation. Initially control concrete mix prepared with M-sand then it is replaced with untreated waste foundry sand (10%, 20%, 30%, 40% and 50%) and biologically treated used foundry sand (10%, 20%, 30%, 40% and 50%). Fresh and hardened properties were studied on all concrete mixes results were compared with conventional concrete. Test result shows that increase in strength of concrete by inclusion of Waste foundry sand (WFS) as a fractional replacement of fine aggregate.
•Spent foundry sand was utilized based on its binder;•Spent waterglass foundry sand (SwFS) was used as a source of fine aggregates for Ca(OH)2-activated slag material (CASM);•CASM mortars ...incorporated with SwFS suffered to 900 ℃ developed similar 3d and 7d compressive strengths to that of the blank mixture;•Dissolved waterglass from SwFS suffered to 900 ℃ worked as an auxiliary activator for CASM.
Utilization of spent foundry sand (SFS) into concrete as a source of fine aggregates has become a hot topic in recent years. However, researchers rarely concerned the binder of SFS and its effects on the performance of concrete. To this regard, this paper investigated the feasibility of incorporating spent waterglass foundry sand (SwFS) into Ca(OH)2-activated slag material (CASM) as a source of fine aggregates towards practical application. Two kinds of SwFS suffered to 100℃ and 900℃ were prepared to reveal the role of the dried waterglass coating of SwFS on the performance of CASM. Experimental results showed that the soluble properities of SwFS determined its properities and performance in CASM. SwFS suffered to 100℃ released SiO32−quickly, causing side reactions with the activator Ca(OH)2, bringing about quick loss of the flow value and obvious reduction of compressive strength of CASM mortars. On the contrast, SwFS suffered to 900℃ release SiO32− in slow speeds and can be an auxiliary activator for CASM. In addition, CASM mortars with SwFS suffered to 900℃ possessed similar 3d and 7d compressive strengths to that of the blank mixture, and got slight decreases of 8.38% to 18.42% at 28d.
Waste Foundry sand (WFS), a major solid waste from metal casting industry, is posing a significant environmental threat owing to its disposal to landfills. In this research, an innovative artificial ...intelligence technique i.e. Multi-Expression Programming (MEP) is applied to model the split tensile strength (ST) and modulus of elasticity (E) of concrete containing waste foundry sand (CWFS). The presented formulations correlate mechanical properties with four input variables i.e. w/c, foundry sand content, superplasticizer content and compressive strength. The results of statistical analysis validate the model accuracy as evident by the low values of objective function (0.033 for E and 0.052 for ST). Moreover, the average error in the predicted values is significantly low i.e. 0.287 MPa and 1.75 GPa for ST and E model, respectively. Parametric study depicts that the models are well trained to accurately predict the trends of mechanical properties with variation in mix parameters. The prediction models can promote the usage of WFS in green concrete thereby preventing waste disposal and contributing towards and sustainable construction.
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•WFS, a hazardous solid waste, causes adverse environmental impact.•Artificial intelligence is used to model mechanical properties of green concrete.•Validation and parametric study is performed to ensure the accuracy of models.•Application of proposed models can contribute towards sustainable construction.
•Fine aggregates were partially replaced by WFS and fly ash to synthesize GPC.•D-optimal mixture design of experiments was opted to formulate mixture compositions.•The empirical models for CS 7 and ...CS 28 were developed, verified, and validated.•RSM was applied to study the effects of mixture composition on compressive strength.•Optimization was performed to maximize the utilization of WFS and fly ash in GPC.
This work examines the partial replacement of fine aggregates with waste foundry sand (WFS) and fly ash, process by-products, to synthesize geopolymer concrete (GPC). D-optimal mixture design of experiments was adopted to guide the proportion of mixture constituents (fine aggregates, WFS, and fly ash) to obtain desired responses (high compressive strengths). The experimentally measured responses/compressive strengths were successfully fitted to Scheffe polynomial model to obtain cubic models which represent compressive strengths of solidified GPC at 7th day curing time (CS 7) and at 28th day curing time (CS 28). The models were statistically evaluated by the standard error of design estimation and experimentally verified by comparing their predicted responses to the independently performed experiments. The models were subjected to analysis of variance (ANOVA) and residuals (diagnostics) for statistical significance and validation, respectively. The established models, hence obtained, were used to assess the impacts of relative proportions of mixture constituents at CS 7 and CS 28. It was observed that, although the highest compressive strength requires a high proportion of fine aggregates, yet, some mixture compositions could be proposed for better utilization of waste materials. Finally, the optimization was performed to maximize the usage of WFS and fly ash. A recipe was identified which yielded 18.9 N/mm² CS 7 and 22.3 N/mm² CS 28 by mere 32 wt. % contribution of fine aggregates in a (fine aggregates + WFS + fly ash) mixture. This study can be helpful in designing experiments and optimizing the utilization of similar waste materials into useful products.
Foundry sand (FS) waste creates a serious solid waste management problem worldwide due to the high volumes produced, necessitating alternatives to landfilling. A possible route is its use in ...concrete; however, the current consensus is that FS can only be used for modest sand replacements, based mostly on evidence on concrete with clay-bound FS (greensand). Conversely, this study assessed salient properties of structural concrete with chemically bound FS (polymeric resin binder), for which there is very little information. Concrete mixes were prepared in which FS replaced regular concrete sand partially or fully. The results showed that unlike greensand, the tested chemically bound FS could replace regular concrete sand fully, giving highly workable mixes with good mechanical properties (compressive, splitting and flexural strengths and static modulus of elasticity) similar to those of mixes with regular concrete sand; the effect of FS content on these properties was not statistically significant. Durability in terms of water absorption, carbonation and alkali–silica reaction tests was not adversely affected. The possibility of using high contents of this type of FS in concrete (as opposed to greensand) gives promise for an additional outlet route for large quantities of this waste material with clear economic and environmental benefits.
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•GEP algorithm is utilized for predicting mechanical properties of concrete incorporating WFS.•Simple and accurate formulations with a wide range of applicability have been ...proposed.•Proposed models can promote the re-utilization of hazardous WFS for development of green concrete.
Waste foundry sand (WFS) is a major pollutant generated from metal casting foundries and is classified as a hazardous material due to the presence of organic and inorganic pollutants which can cause adverse environmental impact. In order to promote the re-utilization of WFS, gene expression programming (GEP) has been employed in this study to develop empirical models for prediction of mechanical properties of concrete made with WFS (CMWFS). An extensive and reliable database of mechanical properties of CMWFS is established through a comprehensive literature review. The database comprises of 234 compressive strength, 163 split tensile strength and 85 elastic modulus results. The four most influential parameters i.e. water-to-cement ratio, WFS percentage, WFS-to-cement content ratio and fineness modulus of WFS are considered as the input parameters for modelling. The mechanical properties can be estimated by the application of proposed simplified mathematical expressions. The performance of the models is assessed by conducting parametric analysis, applying statistical checks and comparing with regression models. The results reflected that the proposed models are accurate and possess a high generalization and prediction capability. The findings of this study can enhance the re-usage of WFS for development of green concrete leading to environmental protection and monetary benefits.
The by-product of the foundry industry is waste foundry sand (WFS). The use of WFS in building materials will safeguard the ecosystem and environmental assets while also durable construction. The use ...of industrial waste in concrete offsets a shortage of environmental sources, solves the waste dumping trouble and provides another method of protecting the environment. Several researchers have investigated the suitability of WFS in concrete production instead of natural river sand in the last few decades to discover a way out of the trouble of WFS in the foundry region and accomplish its recycling in concrete production. However, a lack of knowledge about the progress of WFS in concrete production is observed and compressive review is required. The current paper examines several properties, such as the physical and chemical composition of WFS, fresh properties, mechanical and durability performance of concrete with partially substituting WFS. The findings from various studies show that replacing WFS up to 30% enhanced the durability and mechanical strength of concrete to some extent, but at the same time reduced the workability of fresh concrete as the replacement level of WFS increased. In addition, this review recommended pozzolanic material or fibre reinforcement in combination with WFS for future research.
•Optimization of the use of industrial waste of different natures in cementitious mortars.•Artificial neural network together with response surface for dynamic characterization of cementitious ...mortars.•Natural frequency increase in mortars with polyurethane waste.•Foundry sand with polyurethane are able to increase the damping of cementitious mortars.
Although many studies have reported on the application of experimental, statistical, numerical, and computational tools to composite structures, few have focused on the use of analysis of variance (ANOVA) to analyze experimental data and Artificial Neural Network (ANN) as a technique to predict the modal responses of Portland cement mortars. In this study, by means of DOE and ANN the modal responses of portland cement mortars with polyurethane waste and foundation sand from exhaustion were investigated. The tests were performed by means of free vibration and the analyzed responses were natural frequency and damping factor. The experimental results indicated that the combined PU and FES waste can significantly change the natural frequency and damping of the mortars. This change, when compared to the reference samples, can reach an increase of 11.6% or decrease of 21.7%, depending on the percentage of waste used. The ANN trained with the experimental data showed a high correlation to predict the experimental results.
In this study, ferrous foundry slag was used as a precursor for the synthesis of a geopolymer. The effect of NaOH concentration, liquid solid ratio (L/S), and curing temperature on the unconfined ...compressive strength (UCS) of the synthesized geopolymer was investigated. The optimum concentration was found to be 15 M as it yielded a geopolymer brick with the highest UCS of 8.2 MPa. It was observed that as the concentration of NaOH increases the dissolution of alumina, calcium and silica increases resulting in higher UCS. The SEM results showed zeolite formation in large quantities at 15 M which shows that the geopolymerization reaction was near completion and the calcium, alumina and silicates dissolved in large quantities leading to increased gelling of C-S-H and C-A-H over time filling more pores inside the geopolymer brick. The liquid to the solid ratio that gave the highest UCS of 8.2 MPa was 0.15. The optimum temperature was found to be 80 °C. This increased temperature favoured the dissolution of reactive species and contributed to higher UCS. The results reveal that ferrous foundry sand geopolymers have the potential to be used as a building and construction material.
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