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Cited by 33Environmental Impact and SustainabilitySustainable Building Design and AssessmentSustainable Supply Chain Management

Life cycle assessment and economic analysis of Reusable formwork materials considering the circular economy

Open access
Tighnavard Balasbaneh, Ali, Sher, Willy, Haziman Wan Ibrahim, Mohd·2024·Ain Shams Engineering Journal
DOI 10.1016/j.asej.2023.102585
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Abstract

Economic development and population growth have impacted on fossil-based energy consumption, contributing to environmental pollution. Adopting circular economy research is more pressing than ever to ease pressure on the environment and the economy. Evaluating the best construction materials is not new. To date, many researchers have assessed materials using various criteria. Formwork differs from other construction materials in terms of serviceability and reusability. These materials may be reused multiple times (from 7 to around 50 times). This raises the question of which material is the best from a sustainability perspective. In this paper we have evaluated four of the most widely-used formwork materials used in the construction of buildings in Malaysia. These include plastic, steel, plywood and timber. Evaluations of life cycle assessment (LCA), embodied energy, and life cycle cost (LCC) were conducted from cradle to cradle. For a single use of formwork, timber is best in all categories except human non-carcinogenic toxicity. However, when 50 reuses are considered for the same wall a completely different result arises. In the environmental category, steel formwork produces the lowest emissions and impact in all categories except global warming potential (GWP). Plastic formwork has the lowest carbon emissions. In terms of embodied energy and cost, plastic formwork presents the best option being approximately 20% lower than steel formwork. Because of the inconsistency in the results for LCA, embodied energy, and LCC for 50-cycles of usage, a multi-criteria decision-making (MCDM) tool was used to normalize the results. The MCDM shows that plastic formwork is an ideal choice for sustainability among the alternatives considered.

AI snapshot

Written from the paper’s full text.

TL;DR

This study compares plastic, steel, plywood, and timber formwork for a 20 cm concrete wall (10.8 m²) using cradle-to-cradle LCA, cumulative energy demand, life cycle cost, and AHP-TOPSIS multi-criteria decision-making, evaluated for both one use and 50 reuses. Timber wins on a single use, but once reusability is accounted for, plastic formwork emerges as the best overall sustainability choice.

Key findings

  • For a single use, timber formwork has the lowest impacts in nearly all categories: 55 kg-CO₂eq/m² GWP versus 76 (plywood), 194 (plastic), and 262.9 (steel) kg-CO₂eq/m²; total GWP was 506, 664, 1605, and 2101 kg-CO₂eq for timber, plywood, plastic, and steel respectively.
  • At 50 reuses the ranking reverses: total cradle-to-cradle GWP is 1453 kg-CO₂eq (plastic), 2101 (steel), 3511 (timber), and 4648 (plywood). Steel is lowest in all other environmental categories except GWP; timber becomes worst for human non-carcinogenic toxicity (46 kg 1,4-DCB, 3.1× plastic).
  • Embodied energy at 50 uses totals 23,022 MJ (plastic), 29,522 MJ (steel), 36,834 MJ (timber), and 59,024 MJ (plywood); plastic is ~20% lower than steel. LCC at 50 uses is $5,556 (plastic), $6,099 (steel), $13,055 (timber), and $14,000 (plywood).
  • AHP-TOPSIS ranks plastic first (Pi = 0.95), steel second (0.87), timber third (0.39), plywood fourth (0.22). With equal criteria weights, the best alternative shifts to steel (Pi = 0.92).

Methods

  • Four formwork options (polypropylene plastic FW1, steel FW2, plywood FW3, timber FW4) assessed for a 3 m × 3.6 m, 20 cm thick concrete wall; plastic and steel assumed reusable 50 times, plywood and timber 7 times, with end-of-life recycling/reuse/incineration scenarios (e.g., 90% plastic recycled, 100% steel recycled, 80% wood incinerated).
  • Cradle-to-cradle LCA in SimaPro v9.3 with Ecoinvent 3.3 and ReCiPe Midpoint (H) (GWP, TAP, HCT, OFHH, FRS), plus Cumulative Energy Demand (CED 1.04) for embodied energy; consequential approach, biogenic carbon excluded, adapted to the Malaysian electricity mix.
  • Consequential LCC using material, labour, and transport costs with 3% inflation and 3.2% discount rates; AHP weighting from 60 specialists (construction estimators, project engineers, academics) feeding a TOPSIS ranking, with sensitivity analyses on weights and formwork lifespan.

Limitations

  • Stated by the authors: maintenance and repair were assumed unnecessary over the formwork lifetime; transport to end-of-life location was excluded as assumed similar across scenarios; biogenic CO₂ uptake/emissions were excluded due to lack of accepted methods and Malaysian forestry data; the study covers only concrete walls and omits finished-wall quality, formwork storage, surface finish, work accessibility, and safety.
  • Evident from the text: the 50-use comparison relies on assumed reuse counts (50 vs. 7) drawn from literature and a survey rather than measured field data; the MCDM outcome is sensitive to expert weighting, since equal weighting changes the preferred material from plastic to steel.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.asej.2023.102585

Cites

48 of 48 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

2 of 14 cited sources checked · 2 supported · 0 flagged

  • Premisecitation
    § 1. Introduction

    Approximately 40% to 60% of the cost of construction relates to formwork.

    “Approximately 40 % to 60 % of the cost of construction relates to formwork [14].”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [14] Gowripalan N, Shakor P, Rocker P. Pressure exerted on formwork by self- compacting concrete at early ages: A review. Case Stud Constr Mater 2021;15: e00642. source
  • Premisenone given
    § 650 80 200

    Previous research by Bin Marsono and Balasbaneh only focuses on GWP emissions in LCA analysis.

    “Previous research Bin Marsono and Balasbaneh [8,27,52]only focuses on GWP emissions in LCA analysis.”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [8] Bin Marsono AK, Balasbaneh AT. Combinations of building construction material for residential building for the global warming mitigation for Malaysia. Constr Build Mater 2015;85:100–8. source
    • cites [27] Lausselet C, Lund KM, Brattebø H. LCA and scenario analysis of a Norwegian net- zero GHG emission neighbourhood: The importance of mobility and surplus energy from PV technologies. Environ: Build; 2021. p. 189. source
    • cites [52] Tavares V, Lacerda N, Freire F. Embodied energy and greenhouse gas emissions analysis of a prefabricated modular house: The "Moby" case study. J Clean Prod 2019;212:1044–53. source
  • Findingnone given
    § Abstract

    Plastic formwork has the lowest carbon emissions.

    “Plastic formwork has the lowest carbon emissions.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Formwork would not require maintenance during its lifetime.
    • The authors state this as an assumption: Wood was considered carbon neutral.
    • The authors state this as an assumption: Biogenic CO2 uptake and emissions were excluded from the LCA.
    • The authors state this as an assumption: Biogenic carbon absorbed by forests has not been included because of lack of data about the Malaysian forestry industry.
    • The authors state this as an assumption: Transport of material to its end-of-life location was excluded as it was assumed to be similar for all scenarios.
    • The authors state this as an assumption: 10% of plastic was reused in subsequent projects.
    • The authors state this as an assumption: 80% of wood formwork would be incinerated and 20% was considered to be reused.
    • The authors state this as an assumption: The number of times plastic and steel is assumed to be used is 50, and for plywood and timber seven times.
    • The authors state this as an assumption: After seven uses, new formwork needs to be assembled and 20% of the wood from previous formwork is used in this new formwork.
    • The authors state this as an assumption: Transport of plastic and steel is paid once and seven times for plywood and timber.
    • The authors state this as an assumption: All work is assumed to have been conducted on a single site.
    • The authors state this as an assumption: Wood is burned in an incinerator with appropriate emissions controls.
    • The authors state this as an assumption: Plastics are incinerated in an incinerator.
    • The authors state this as an assumption: Data about negative carbon from biomass are not available.
    • Rests on an assumption: At the end of its life, steel formwork can be recycled.
    • Rests on an assumption: Timber and plywood are frequently incinerated after 7 uses.
    • Rests on an assumption: Formwork reuse contributes to cost savings and material waste reduction.
    • Rests on an assumption: When plastic formwork is damaged or decommissioned, it can be crushed and recycled.
    • Rests on an assumption: Steel is often recycled, followed by plastics.
    • Rests on an assumption: Using waste at the end of the life of formwork can have a marked economic impact in terms of economic efficiency in line with circular principles.
    • Rests on an assumption: Formwork materials are only used during construction and do not form part of finished buildings.
  • Findingown data
    § Abstract

    In the environmental category, steel formwork produces the lowest emissions and impact in all categories except global warming potential (GWP).

    “In the environmental category, steel formwork produces the lowest emissions and impact in all categories except global warming potential (GWP).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Formwork would not require maintenance during its lifetime.
    • The authors state this as an assumption: Wood was considered carbon neutral.
    • The authors state this as an assumption: Biogenic CO2 uptake and emissions were excluded from the LCA.
    • The authors state this as an assumption: Biogenic carbon absorbed by forests has not been included because of lack of data about the Malaysian forestry industry.
    • The authors state this as an assumption: Transport of material to its end-of-life location was excluded as it was assumed to be similar for all scenarios.
    • The authors state this as an assumption: 10% of plastic was reused in subsequent projects.
    • The authors state this as an assumption: 80% of wood formwork would be incinerated and 20% was considered to be reused.
    • The authors state this as an assumption: The number of times plastic and steel is assumed to be used is 50, and for plywood and timber seven times.
    • The authors state this as an assumption: After seven uses, new formwork needs to be assembled and 20% of the wood from previous formwork is used in this new formwork.
    • The authors state this as an assumption: Transport of plastic and steel is paid once and seven times for plywood and timber.
    • The authors state this as an assumption: All work is assumed to have been conducted on a single site.
    • The authors state this as an assumption: Wood is burned in an incinerator with appropriate emissions controls.
    • The authors state this as an assumption: Plastics are incinerated in an incinerator.
    • The authors state this as an assumption: Data about negative carbon from biomass are not available.
    • Rests on an assumption: At the end of its life, steel formwork can be recycled.
    • Rests on an assumption: Timber and plywood are frequently incinerated after 7 uses.
    • Rests on an assumption: Formwork reuse contributes to cost savings and material waste reduction.
    • Rests on an assumption: When plastic formwork is damaged or decommissioned, it can be crushed and recycled.
    • Rests on an assumption: Steel is often recycled, followed by plastics.
    • Rests on an assumption: Using waste at the end of the life of formwork can have a marked economic impact in terms of economic efficiency in line with circular principles.
    • Rests on an assumption: Formwork materials are only used during construction and do not form part of finished buildings.
  • Findingown data
    § Abstract

    When 50 reuses are considered for the same wall, the results differ completely from single-use results.

    “However, when 50 reuses are considered for the same wall a completely different result arises.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Formwork would not require maintenance during its lifetime.
    • The authors state this as an assumption: Wood was considered carbon neutral.
    • The authors state this as an assumption: Biogenic CO2 uptake and emissions were excluded from the LCA.
    • The authors state this as an assumption: Biogenic carbon absorbed by forests has not been included because of lack of data about the Malaysian forestry industry.
    • The authors state this as an assumption: Transport of material to its end-of-life location was excluded as it was assumed to be similar for all scenarios.
    • The authors state this as an assumption: 10% of plastic was reused in subsequent projects.
    • The authors state this as an assumption: 80% of wood formwork would be incinerated and 20% was considered to be reused.
    • The authors state this as an assumption: The number of times plastic and steel is assumed to be used is 50, and for plywood and timber seven times.
    • The authors state this as an assumption: After seven uses, new formwork needs to be assembled and 20% of the wood from previous formwork is used in this new formwork.
    • The authors state this as an assumption: Transport of plastic and steel is paid once and seven times for plywood and timber.
    • The authors state this as an assumption: All work is assumed to have been conducted on a single site.
    • The authors state this as an assumption: Wood is burned in an incinerator with appropriate emissions controls.
    • The authors state this as an assumption: Plastics are incinerated in an incinerator.
    • The authors state this as an assumption: Data about negative carbon from biomass are not available.
    • Rests on an assumption: At the end of its life, steel formwork can be recycled.
    • Rests on an assumption: Timber and plywood are frequently incinerated after 7 uses.
    • Rests on an assumption: Formwork reuse contributes to cost savings and material waste reduction.
    • Rests on an assumption: When plastic formwork is damaged or decommissioned, it can be crushed and recycled.
    • Rests on an assumption: Steel is often recycled, followed by plastics.
    • Rests on an assumption: Using waste at the end of the life of formwork can have a marked economic impact in terms of economic efficiency in line with circular principles.
    • Rests on an assumption: Formwork materials are only used during construction and do not form part of finished buildings.
  • May combine two claims. 45
  • Classified as probably not a substantial claim. 15
  • The quote only partly states this claim. 2

  • May combine two claims.

    Findingnone given

    Our study was based on polypropylene panels 1200 mm by 600 mm. These weigh 11 kg less than timber formwork of the same size (15 kg).

    “Our study was based on polypropylene panels 1200 mm by 600 mm. These weigh 11 kg less than timber formwork of the same size (15 kg).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Plywood formwork production and construction for first-time use emits 819 kg-CO2eq, equivalent to 76 kg-CO2eq per square metre, which is 27% higher than timber.

    “The second-lowest emissions relate to plywood formwork with 819 kg-CO2eq for production and construction. The emissions of one square metre of plywood formwork are 76 kg-CO2eq which is 27 % higher than for timber.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Total embodied energy of steel formwork is 1.3, 3.5, and 5.6 times higher than plastic, plywood, and timber formwork.

    “Finally, the total embodied energy of steel formwork is 1.3, 3.5, and 5.6 times higher than plastic, plywood, and timber formwork.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For timber formwork, wood sheathing panel contributes 44%, another wood sheathing panel 17%, and transportation 13%.

    “The timber (FW4) formwork's highest costs relate to the wood sheathing panel (44 %), Wood sheathing panel (17 %), and transportation (13 %).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data
    § 650 80 200

    In this study, GWP is the only criterion that identifies plastic as an ideal formwork material, while other criteria are against these choices.

    “However, in the study reported here GWP is the only criterion that identifies plastic is an ideal formwork material (Fig. 3) and the results of other criteria and against these choices.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For plywood formwork, plywood sheathing panel contributes 47% of cost and pull-push props 15%.

    “The highest cost for plywood (FW3) relates to the plywood sheathing panel as the main part of formwork contributing 47 % of the cost and pull–push props that align the sheathing in place during the casting of concrete accounting for 15 % of cost.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Findingown data
    § 5. Conclusion

    An analysis of 50 uses of those materials revealed different results.

    “However, an analysis of 50 uses of those materials revealed different results.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Total GWP for single use is 1605 kg-CO2eq for plastic, 2101 kg-CO2eq for steel, 664 kg-CO2eq for plywood, and 506 kg-CO2eq for timber.

    “Finally, the total GWP are 1605 kg-CO2eq, 2101 kg-CO2eq, 664 kg-CO2eq, and 506 kg-CO2eq for plastic, steel, plywood, and timber formwork, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Plastic formwork embodied energy: production 34800 MJ, transportation 222 MJ, and recycling net saving -12000 MJ.

    “The embodied energy for the production and transportation of plastic formwork are 34800 MJ and 222 MJ. However, the net energy saving for recycling equals − 12000 MJ which needs to be deducted from the overall embodied energy.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingreasoning

    For 50 cycles, transportation is included 7 times (six times more than single use).

    “Transportation needs to be included six times more for transferring the formwork to site (a total of 7 times).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Plywood and timber formwork can only be used seven times.

  • May combine two claims.

    Findingown data
    § 5. Conclusion

    MCDM showed that plastic was the ideal choice for formwork systems in the construction concrete industry, followed by steel.

    “MCDM showed that plastic was the ideal choice for formwork systems in the construction concrete industry, followed by steel.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For one use, timber formwork has the lowest environmental impact compared to plastic; plastic generates the most emissions and impacts in all environmental categories except GWP.

    “The overall result for one use shows that timber formwork has the lowest environmental impact compared to plastic. Plastic generates the most emissions and impacts in all environmental categories except GWP (Table 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning
    § 650 80 200

    Weighted normalized GWP values are 0.05 for FW1, 0.07 for FW2, 0.15 for FW3, and 0.11 for FW4.

    “For example, the weighted normalized matrix of GWP is 0.05, 0.07, 0.15 and 0.11 for FW1, FW2, FW3, and FW4, respectively.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    For 50 uses, plywood has the highest embodied energy (69720 MJ production/manufacturing) versus 34800 MJ for plastic, 51300 MJ for steel, and 42350 MJ for timber; plywood has 2, 1.3, and 1.6 times more embodied energy than plastic, steel, and timber respectively.

    “Plywood has the highest embodied energy (69720 MJ for production and manufacturing stage versus 34800 MJ, 51300 MJ, and 42350 MJ for plastic, steel and timber formwork, respectively.) Plywood thus has 2, 1.3 and 1.6 times more embodied energy than plastic, steel and timber formwork.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Plywood and timber formwork can only be used seven times.

  • May combine two claims.

    Findingown data

    Resale of formwork has a net income; net cost savings are -378 for plastic, -525 for steel, -136 for plywood, and -121 for timber; steel shows the best performance.

    “The resale of formwork has a net income, and steel shows the best performance. The net cost savings are − 378, − 525, − 136, and − 121 for plastic, steel, plywood, and timber formwork.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For 50 uses, plywood formwork has the highest cost of $14,000 followed by timber at $13,055; renewable materials are not suitable because their life span is shorter; plastic LCC is $5,556, lower than steel by $6,144; plastic formwork is the best option in the LCC category.

    “Finally, after 50 uses, the plywood formwork has the highest cost of $14,000 followed by timber formwork at $13,055. This shows that renewable materials are not suitable because their life span is shorter when used as formwork. Alternative materials such as steel and plastic have cost advantages. The LCC of plastic is $5,556, which is lower than steel by $6,144. Therefore, it can be concluded that”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Plywood and timber formwork can only be used seven times.

  • May combine two claims.

    Findingown data

    For a single use, net energy saving (carbon offset) is -811 kg-CO2eq for steel, -568 kg-CO2eq for plastic, and -228 kg-CO2eq for timber.

    “The net energy saving for steel is − 811 kg-CO2eq, followed by − 568 kg-CO2eq, and − 228 kg-CO2eq, for plastic and timber for a single use, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    Plywood has 2.7 and 2 times more emissions than plastic and steel formwork for the production stage.

    “This is because plywood has 2.7 and 2 times more emissions than plastic and steel formwork for the production stage.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 5. Conclusion

    Formwork evaluated based on one use identified timber as the ideal choice in all environmental categories, followed by plywood.

    “Firstly, formwork was evaluated based on one use. This identified timber as the ideal choice in all environmental categories, followed by plywood.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given
    § 650 80 200

    The GWP values for 50 cycles are 1604 kg-CO2eq for plastic, 2101 kg-CO2eq for steel, 3320 kg-CO2eq for plywood, and 2530 kg-CO2eq for timber formwork.

    “For example, the GWP are 1604 kg-CO2eq, 2101 kg-CO2eq, 3320 kg-CO2eq, and 2530 kg-CO2eq for plastic, steel, plywood, and timber formwork, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 650 80 200

    Decreasing the number of uses of timber and plywood formwork from seven does not change the result; plastic formwork remains the preferable choice.

    “It became apparent that decreasing the number of uses from seven does not change the result and plastic formwork is still the preferable choice.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Timber formwork production and construction for first-time use (10.8 m2) emits 594 kg-CO2eq, equivalent to 55 kg-CO2eq per square metre.

    “The total emissions for production and construction of the formwork (3 × 3.6 = 10.8 m2) was calculated as 594 kg-CO2eq for first-time use. Thus, constructing one square metre of timber formwork releases 55 kg-CO2eq into the atmosphere.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    End-of-life net energy savings are -12000 MJ for plastic, -22000 MJ for steel, -1750 MJ for plywood, and -1010 MJ for timber; steel has the highest net energy saving, 1.8 times higher than plastic.

    “The end-of-life avoided production is a net energy saving equal to − 12000 MJ, − 22000 MJ, − 1750 MJ and-1010 MJ for plastic, steel, plywood and timber formwork as shown in Fig. 6. Steel has the highest net energy saving among all the alternatives. The energy recovered from recycling steel formwork is 1.8 times higher than the net energy reduction for plastic.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given
    § 650 80 200

    Decreasing the number of times wood can be reused increases cost and environmental emissions.

    “By decreasing the number of times of wood can be reused, the cost and environmental emissions increased.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Plastic formwork single use emits 2100 kg-CO2eq total, 194 kg-CO2eq per square metre, which is 72% higher than timber and 61% higher than plywood.

    “When used once, it releases 2100 kg-CO2eq emissions. The emissions for one square metre of plastic formwork are equal to 194 kg-CO2eq. This is 72 % and 61 % higher than timber and plywood, respectively, for a single use.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Steel has the highest embodied energy among alternatives: 51300 MJ manufacturing, 222 MJ transportation, 1.5 times higher than plastic; recycling net reduction -22000 MJ.

    “Steel has the highest embodied energy among the alternatives, with 51300 MJ and 222 MJ for manufacturing and production, and transportation, which is 1.5 times higher than the embodied energy of plastic formwork. Therefore, the net reduction for recycling steel formwork is − 22000, which is deducted from the total energy to calculate the total embodied energy for steel.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Plywood embodied energy: 9960 MJ production, 222 MJ transportation, -1750 MJ end-of-life benefits.

    “The embodied energy of plywood is 9960 MJ, 222 MJ, − 1750 MJ for manufacturing and production, transportation and end of life benefits, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For a single use, after including transportation and end-of-life, total OFHH for plastic is 5.9 kg NOxeq, which is 1.7, 2.2, and 4.5 times more than steel, plywood, and timber formwork respectively.

    “Once the emissions related to transportation and the end-of-life impact were taken into account, the total emissions for plastic decreased to 5.9 NOxeq due to recycling. A single use of plastic formwork had 1.7, 2.2, and 4.5 times more emissions than steel, plywood and timber formwork.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingnone given

    Primary energy demand for plastic is higher than for timber and steel; embodied energy per kg is 70 MJ/kg for plastic versus 35 MJ/kg for steel.

    “For example, the primary energy demand for plastic is higher than for timber and steel. The embodied energy for one kg of plastic is 70 Kg/MJ versus 35 Kg/MJ for steel.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data
    § 650 80 200

    Academics prioritized GWP highest, then embodied energy, cost, FRS, OFHH, HCT, and TAP.

    “Unlike the two previous groups, the academics strongly believed that GWP should be considered the highest priority. They considered embodied energy and cost as second and third, respectively. The FRS, OFHH, HCT, and TAP were their fourth to seventh priorities.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Steel formwork production and manufacturing for single use emits 2840 kg-CO2eq total, 262.9 kg-CO2eq per square metre, the highest for one usage, and 79%, 71%, and 27% higher than timber, plywood, and plastic formwork respectively.

    “The highest emissions are for steel formwork for the production and manufacturing stage, being 2840 kg-CO2eq. The emissions for one square metre of steel formwork are 262.9 kg-CO2eq, being the highest for one usage. The steel formwork has higher emissions of 79 %, 71 %, and 27 % than timber, plywood, and plastic formwork respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Total TAP emissions for 50 cycles are 11.86 kg SO2eq for plastic, 5.52 kg SO2eq for steel, 18.75 kg SO2eq for plywood, and 12.23 kg SO2eq for timber.

    “The total emissions are 11.86 Kg SO2eq, 5.52 Kg SO2eq, 18.75 Kg SO2eq, and 12.23 Kg SO2eq for plastic, steel, plywood and timber formwork, respectively.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Plywood and timber formwork can only be used seven times.

  • May combine two claims.

    Findingown data

    Total embodied energy for 50 uses is 23022 MJ for plastic, 29522 MJ for steel, 59024 MJ for plywood, and 36834 MJ for timber; plywood has 2.5, 2, and 1.6 times more embodied energy than plastic, steel, and timber; plastic is the best material for embodied energy for 50 uses.

    “Finally, the total embodied energy is 23022 MJ, 29522 MJ, 59024 MJ, and 36834 MJ for plastic, steel, plywood and timber formwork. This shows that plywood has 2.5, 2, and 1.6 times more embodied energy than plastic, steel and timber formwork. Thus, the best materials from the perspective of embodied energy are plastic as they require less energy for 50 uses.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Plywood and timber formwork can only be used seven times.

  • May combine two claims.

    Findingnone given
    § 5. Conclusion

    Steel formwork has a lower impact on terrestrial acidification potential, human non-carcinogenic toxicity, ozone formation, human health, and fossil resource scarcity criteria.

    “However, steel formwork has a lower impact on terrestrial acidification potential, human non-carcinogenic toxicity, ozone formation, human health, and fossil resource scarcity criteria.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Construction estimators prioritized cost; project engineers prioritized cost, then GWP, then embodied energy; second and third ranks are close (0.23 versus 0.22).

    “The first group of respondents was of construction estimators whose priority was cost. The project engineer believed strongly that cost should be prioritised when choosing formwork. Literature[42]indicated that formwork accounts for up to 25 % or more of the cost of the structure of a building. The project engineer considered GWP impact as secondary and embodied energy as third. Of note is that”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [42] Prajapati, R., Pitroda, J. and Bhavsar, J. (2014). Plastic Formwork : New Era for Construction Sector.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Findingown data

    For 50 uses, plywood formwork has the highest emissions (changed from plastic); plywood contributes three times more emissions than plastic in GWP, and has 2.4, 1.7, 4, and 2.5 times more impact than plastic for TAP, HCT, OFHH, and FRS respectively.

    “Surprisingly, after evaluating 50 uses of timber and plywood formwork, the result changed from plastic (with the highest emissions) to plywood formwork. Plywood contributes three times more emissions than plastic formwork in the GWP category. This trend was similar for other environmental impacts. Plywood has a 2.4, 1.7, 4-, and 2.5-times more impact than plastic formwork (second-highest rank) for”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Plywood and timber formwork can only be used seven times.

  • May combine two claims.

    Findingown data

    For a single use, plastic formwork has the highest TAP impact, 2, 4, and 7 times higher than steel, plywood, and timber respectively; total TAP emissions are 11.7 kg SO2eq for FW1, 5.5 kg SO2eq for FW2, 2.7 kg SO2eq for FW3, and 1.7 kg SO2eq for FW4.

    “Plastic formwork has the highest impact in this category with 2, 4, and 7 times higher emissions than steel, plywood and timber formwork respectively. The total emission is 11.7Kg SO2eq, 5.5Kg SO2eq, 2.7Kg SO2eq, and 1.7 Kg SO2eq for FW1, FW2, FW3, and FW4, respectively.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Findingreasoning
    § 650 80 200

    Positive ideal solution (A+) values are 0.0519, 0.0171, 0.0211, 0.017, 0.0335, 0.0534, and 0.0562; negative ideal solution (A-) values are 0.1502, 0.0464, 0.0975, 0.0899, 0.0876, 0.137, and 0.1427.

    “Thus, the positive ideal solution (A+) is 0.0519, 0.0171, 0.0211, 0.017, 0.0335, 0.0534, and 0.0562, versus the negative ideal solution (A− ) as 0.1502, 0.0464, 0.0975, 0.0899, 0.0876, 0.137, and 0.1427.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For steel formwork single use, transportation is responsible for 52% and 16% of cost, whalers contribute 15%, and other components/process costs are bolts 2%, tie rods 2%, plate nuts 7%, wages 4%, and 2% respectively.

    “Transportation is responsible for 52 % and 16 % of the cost. The whalers contribute 15 % of the total cost for one use. Other components and process costs are bolts, tie rods, plate nuts, and wages of 2 %, 2 %, 7 %, 4 %, and 2 %, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning
    § 30 13 390

    Considering only a single use of formwork will give an unreliable result and provide little guidance.

    “Considering only a single use will give an unreliable result and provide little guidance.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation
    § 1. Introduction

    Steel formwork is strong and durable, but it can also be expensive.

    “Steel formwork is strong and durable, but it can also be expensive [22].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [22] Li W, Lin X, Bao DW, Min Xie Y. A review of formwork systems for modern concrete construction. Structures 2022;38:52–63. source

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given
    § 1. Introduction

    No published sustainability studies consider the reusability characteristics and multiple uses of different types of formwork.

    “Finally, as far as we can ascertain, there are no published sustainability studies that consider the reusability characteristics and multiple uses of different types of formwork.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    The computed Consistency Ratio (CR) should not exceed 0.1 to ensure consistency of the comparison framework.

    “To ensure the consistency of the comparison framework, the computed Consistency Ratio (CR) should not exceed 0.1.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Saaty, 2008

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The functional unit of 1 m2 of concrete wall allows different materials to be compared equitably.

    “The functional units used in this study are based on 1 m2 of concrete wall. This allows different materials to be compared equitably.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisereasoning
    § 1. Introduction

    There is no consensus on which formwork material is best regarding environmental, energy, and cost considerations.

    “Despite current research on sustainability and life cycle assessment (LCA) for different construction materials, it is not clear which ones are best for formwork regarding environmental, energy, and cost considerations.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation
    § 1. Introduction

    Wood is cheaper than plastic or steel formwork.

    “However, wood is cheaper than plastic or steel formwork.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [22] Li W, Lin X, Bao DW, Min Xie Y. A review of formwork systems for modern concrete construction. Structures 2022;38:52–63. source

  • May combine two claims.

    Premisecitation
    § 1. Introduction

    Wood formwork can only be used a limited number of times and is prone to swelling, twisting and cracking.

    “Wood formwork can only be used a limited number of times and is prone to swelling, twisting and cracking.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [22] Li W, Lin X, Bao DW, Min Xie Y. A review of formwork systems for modern concrete construction. Structures 2022;38:52–63. source

  • Classified as probably not a substantial claim.

    Premisecitation
    § 1. Introduction

    Formwork can significantly impact on construction project cost and duration as well as other activities.

    “In summary, formwork can significantly impact on construction project cost and duration as well as other activities [46].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [46] Shin Y, Kim T, Cho H, Kang KI. A formwork method selection model based on boosted decision trees in tall building construction. Autom Constr 2012;23:47–54. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The plastic shuttering system (FW1) is novel because of its reusability, lightness, solidity, recyclability, universality, durability and simplicity.

    “The plastic shuttering system (FW1) is novel because of its reusability, lightness, solidity, recyclability, universality, durability and simplicity [39].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [39] Post, L. (2020). Life Cycle Analysis of three polystyrene waste scenarios Biodegradation by mealworms as an alternative to incineration or recycling. Peña, C. et al. Using life cycle assessment to achieve a circular economy. Int. J. Life Cycle

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Plastic formwork may be used an average of 50 times and is considered to have one of the longest life expectancies of the options.

    “The first option is for plastic formwork [24]. This may be used an average of 50 times and is considered to have one of the longest life expectancies of the options.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [24] Lo CL. Environmental benefits of renewable building materials: A case study in Taiwan. Energ Buildings 2017;140:236–44. https://doi.org/10.1016/j. enbuild.2017.02.010. source

  • May combine two claims.

    Interpretationreasoning

    Almost three times more steel formwork is required than plastic formwork, which is the main reason steel formwork has higher embodied energy than plastic.

    “However, almost three times more steel formwork is required than plastic formwork, which is the main reason why steel formwork has higher embodied energy than plastic (Fig. 5).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    For 50 uses, plywood contributed the most OFHH, followed by timber; plastic and steel are considered better choices for 50 uses despite not being appropriate for a single formwork use.

    “The total emissions for 50 uses show that plywood contributed the most, followed by timber. Thus, despite plastic and steel not being appropriate options for a single formwork use, for 50 uses, these materials are considered better choices.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Plywood and timber formwork can only be used seven times.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation
    § 4. Discussion

    One study by Kazi and F. P. [20] evaluated alternative formwork materials such as timber, plastic and steel, showing that plastic was the cheapest option.

    “One such study by, Kazi.,Kazi and F, p, [20]evaluated alternative formwork materials such as timber, plastic and steel, showing that plastic was the cheapest option.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Kazi A, F, p,. Comparative Study and Decision Making for a Formwork Technique To Be Adopted on a Construction Site in Mumbai. International Journal of Research in Engineering and Technology 2015;04(12):234–8. https://doi.org/10.15623/ijr et.2015.0412045.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given
    § 650 80 200

    The number of environmental impacts and human subjectivity involved in the AHP method can alter the final results.

    “Besides, the number of environmental impacts and human subjectivity involved in the AHP method can alter the final results.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The higher CO2 emissions for steel formwork compared to plastic are due to a larger quantity of steel required (almost three times), even though per kg plastic has higher emissions than steel.

    “The higher emissions for steel relate to a larger quantity of steel (almost three times). Otherwise, the emissions for 1 kg of plastic are higher than for 1 kg of steel.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Study design and conductnone given

    CR less than 0.1 indicates that the comparison matrix is consistent.

    “CRa less than 0.1 indicates that the comparison matrix is consistent.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation
    § 4. Discussion

    The result of the current study is compatible with the study by Kazi and F. P. [20] that plastic was the cheapest option.

    “This result is compatible with the current study.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning
    § 4. Discussion

    The main differences between steel and plastic formwork remain those of environmental impact, embodied energy and economic cost.

    “Thus the main differences between steel and plastic formwork remain those of environmental impact, embodied energy and economic cost.”
    Quote in the paperSubstantial claim
58 of 58

  • The authors state this as an assumption.

    Formwork would not require maintenance during its lifetime.

    “It was assumed that the formwork would not require maintenance during its lifetime.”

  • The authors state this as an assumption.

    Wood was considered carbon neutral.

    “As a result, wood was considered carbon neutral.”

  • The authors state this as an assumption.

    Biogenic CO2 uptake and emissions were excluded from the LCA.

    “Thus, the LCA excluded biogenic CO2 uptake and emissions.”

  • The authors state this as an assumption.

    Biogenic carbon absorbed by forests has not been included because of lack of data about the Malaysian forestry industry.

    “Additionally, the biogenic carbon absorbed by forests has not been included because of the lack of data about the Malaysian forestry industry.”

  • The authors state this as an assumption.

    Transport of material to its end-of-life location was excluded as it was assumed to be similar for all scenarios.

    “A limitation of this approach is that the transport of material to its end-of-life location was excluded as it was assumed to be similar for all scenarios.”

  • The authors state this as an assumption.

    10% of plastic was reused in subsequent projects.

    “It was assumed that 10 % of plastic was reused in subsequent projects.”

  • The authors state this as an assumption.

    80% of wood formwork would be incinerated and 20% was considered to be reused.

    “Also, it was assumed that 80 % of wood formwork would be incinerated and 20 % was considered to be reused.”

  • The authors state this as an assumption.

    The number of times plastic and steel is assumed to be used is 50, and for plywood and timber seven times.

    “Specifically, the number of times plastic and steel is assumed to be used is 50 [24], and for plywood and timber seven times [43].”

  • The authors state this as an assumption.

    After seven uses, new formwork needs to be assembled and 20% of the wood from previous formwork is used in this new formwork.

    “Thus, after seven uses, we have assumed that new formwork needs to be assembled and that 20 % of the wood from previous formwork is used in this new formwork.”

  • The authors state this as an assumption.

    Transport of plastic and steel is paid once and seven times for plywood and timber.

    “We have further assumed that the transport of plastic and steel is paid once and seven times for plywood and timber.”

  • The authors state this as an assumption.

    All work is assumed to have been conducted on a single site.

    “All work is assumed to have been conducted on a single site.”

  • The authors state this as an assumption.

    Wood is burned in an incinerator with appropriate emissions controls.

    “LCI values were sourced from the Ecoinvent database assuming that wood is burned in an incinerator with appropriate emissions controls.”

  • The authors state this as an assumption.

    Plastics are incinerated in an incinerator.

    “Plastics are also assumed to have been incinerated in an incinerator”

  • The authors state this as an assumption.

    Data about negative carbon from biomass are not available.

    “Data about the negative carbon from biomass are not available.”

  • The paper relies on this without support.

    At the end of its life, steel formwork can be recycled.

    “At the end of its life, steel formwork can be recycled.”

  • The paper relies on this without support.

    Timber and plywood are frequently incinerated after 7 uses.

    “Timber and plywood are frequently incinerated after 7 uses.”

  • The paper relies on this without support.

    Formwork reuse contributes to cost savings and material waste reduction.

    “Formwork reuse contributes to cost savings and material waste reduction.”

  • The paper relies on this without support.

    When plastic formwork is damaged or decommissioned, it can be crushed and recycled.

    “Furthermore, when plastic formwork is damaged or decommissioned, it can be crushed and recycled.”

  • The paper relies on this without support.

    Steel is often recycled, followed by plastics.

    “Steel is often recycled, followed by plastics.”

  • The paper relies on this without support.

    Using waste at the end of the life of formwork can have a marked economic impact in terms of economic efficiency in line with circular principles.

    “Using waste at the end of the life of formwork can have a marked economic impact in terms of economic efficiency in line with circular principles.”

  • The paper relies on this without support.

    Formwork materials are only used during construction and do not form part of finished buildings.

    “Formwork materials are only used during construction and do not form part of finished buildings.”

  • The paper relies on this without support.

    A consequential analysis model uses a different approach from attributional and conventional assessment methods.

    “In contrast to the attributional and conventional assessment methods, a consequential analysis model uses a different approach.”

  • The paper relies on this without support.

    Plywood and timber formwork can only be used seven times.

    “That is because each of those materials can only be used seven times.”

  • The paper relies on this without support.

    Wood and wooden materials are recognised as sustainable choices compared to steel or plastic.

    “This is despite wood and wooden materials being recognised as sustainable choices compared to steel or plastic.”

  • The paper relies on this without support.

    To date there is little published research that compares different formwork materials.

    “To date there is little published research that compares different formwork materials.”

  • The paper relies on this without support.

    There are few studies that evaluate the LCA of formwork.

    “There are few studies that evaluate the LCA of formwork.”
26 of 26

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Conclusion reverses the single-use plastic-versus-steel emissions ranking

    Major

    The conclusion says plastic has lower emissions than steel in every category except GWP. The results instead state that plastic has higher human non-carcinogenic toxicity than steel; they also give plastic a higher single-use acidification total.

  • Conclusion calls timber best for single-use toxicity despite plywood ranking best

    Major

    The conclusion says timber is ideal in all single-use environmental categories, whereas the results explicitly identify plywood as having the lowest human non-carcinogenic toxicity.

  • Plastic's 50-use acidification result differs between text and decision matrix

    Major

    The results text gives plastic formwork's 50-use terrestrial acidification as 11.86 Kg SO2eq, while the initial decision matrix lists 7.88 for FW1.

  • Plywood's 50-use energy total does not add up

    Minor

    The stated production, transport, and end-of-life figures sum to 69,524 MJ, rather than the reported 59,024 MJ.

    Reported 59024 · recomputed 69524

  • Timber's 50-use energy total does not add up

    Minor

    The stated production, transport, and end-of-life figures sum to 42,894 MJ, rather than the reported 36,834 MJ.

    Reported 36834 · recomputed 42894

  • Fifty-use plastic and steel costs differ from the decision matrix

    Minor

    The economic analysis reports $5,556 for plastic and $6,144 for steel; the initial decision matrix instead lists $5,511 and $6,099.

6 of 6

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. Asadi, 2017, comparative study for evaluation of different form work systems utilization in construction projects, Int J Mech Eng Technol, 8, 21
  2. Hill, 2018, The Environmental Impacts of Wood Compared to Other Building Materials, Vol. 4, Issue 56
  3. Mohammed Taher Al-ashwal, 2017, Redzuan Abdullah, Rozana Zakaria, Traditional formwork system sustainability performance: experts’ opinion, IOP Conf, Ser: Mater Sci Eng, 271

Cited by

Sorted by citations

Related

Authors
Tighnavard Balasbaneh, A., Sher, W., & Haziman Wan Ibrahim, M.
Affiliations
University of Newcastle Australia (AU)
ORCID
Sher, Willy
Venue
Ain Shams Engineering Journal
Publisher
Elsevier BV
Published
2024-04
Volume
15
Issue
4
Pages
102585
ISSN
2090-4479 (ISSN-L)
DOI
10.1016/j.asej.2023.102585
OpenAlex
W4389767261
Semantic Scholar
0c2e7bd39b8247deb2aca02a837885ff230b1a06
Cited by
33
References
45
Citations by year
2026: 8 · 2025: 19 · 2024: 6
FWCI
2.74
Type
journal article
Language
en
Open access
Licence
Locations
  • Ain Shams Engineering Journal (publishedVersion, cc-by-nc-nd)
  • Research Open (London South Bank University) (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Funders
UTHM
Topics
  • Physical Sciences › Environmental Science › Environmental Engineering › Environmental Impact and Sustainability
  • Physical Sciences › Engineering › Building and Construction › Sustainable Building Design and Assessment
  • Social Sciences › Business, Management and Accounting › Strategy and Management › Sustainable Supply Chain Management
Keywords
circular economy, building materials, steel formwork, plywood formwork, timber formwork, life cycle cost, embodied energy, multi-criteria decision making, sustainability assessment, global warming potential, Malaysia

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-18.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-18.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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