Loughborough University
Sardinia paper - Plasterboard prototypes.pdf (806.28 kB)

Assessment of plasterboards containing chemically modified gypsum waste

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conference contribution
posted on 2023-10-19, 13:24 authored by Miguel Castro-Diaz, Mohamed OsmaniMohamed Osmani, Sergio Cavalaro, Paul Needham, Scott Newport, Meaghan Sands, Bill Parker

The standard recycling process for construction, refurbishment and demolition plasterboard waste involves several mechanical steps that include manual segregation, grinding, sieving, and ferrous and non-ferrous magnetic separation. However, one of the main challenges to obtain suitable recycled gypsum from refurbishment and demolition (post-consumer) plasterboard waste comes from the difficulty of achieving consistently high purity levels via current mechanical recycling technologies. In addition, post-consumer plasterboard waste contains water-soluble impurities that affect paper-gypsum bonding during plasterboard production. As a result, most post-consumer plasterboard waste is not recycled and ends up in landfills, decomposing and releasing toxic hydrogen sulphide, or used in low-grade applications such as agriculture or additive in cement production. A modified mechanical process and a novel acid leaching purification process were developed and combined to obtain a recycled gypsum product from post-consumer plasterboard waste with consistent purity values above 96 wt%, fulfilling all quality requirements from plasterboard manufacturers. After acid leaching, the purified gypsum was recovered via two methodologies: i) filtration and gypsum cake washing, and ii) acid neutralisation and filtration. Then, plasterboards with dimensions 200 mm × 200 mm × 12.5 mm were prepared at laboratory scale containing either 35 wt% of purified gypsum (washed or neutralised) or 10 wt% of business-as-usual recycled gypsum. These plasterboards were characterised to determine their thermal, physical and mechanical properties. The results showed no significant differences in the thermal, physical and mechanical properties of the plasterboards containing 35 wt% purified gypsum and the plasterboard with 10 wt% recycled gypsum. These findings validate the introduction of high shares of purified gypsum (35 wt%) during standard plasterboard manufacturing. 


Innovative Circular Economy Based solutions demonstrating the Efficient recovery of valuable material Resources from the Generation of representative End-of-Life building materials

European Commission

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  • Architecture, Building and Civil Engineering

Published in

Proceedings SARDINIA 2023


19th International Symposium on Waste Management, Resource Recovery and Sustainable Landfilling


CISA Publisher - Eurowaste Srl.


  • VoR (Version of Record)

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© CISA Publisher

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This is a conference paper presented at the 19th International Symposium on Waste Management, Resource Recovery and Sustainable Landfilling and will be published in upcoming Proceedings SARDINIA 2023 by CISA Publisher: https://cisapublisher.com/

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  • en


Sardinia, Italy

Event dates

9th October 2023 - 13th October 2023


Dr Miguel Castro Diaz. Deposit date: 13 October 2023

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