Abstract
Scott Bros (SB) Ltd.’s recycling plant for soil and aggregate washing is projected to generate 225,000 tonnes of residual waste material, known as 'filter cake,' annually. This high-volume, low-value waste stream presents significant management and disposal challenges. This study explores the potential of using 'filter cake' as a raw material in low-carbon non-structural (non-standard) concrete production, contributing to the circular economy. The research aimed to develop low-carbon concrete by maximising recycled ingredients and minimising CEM-I content. Concrete cube samples (150 mm) were prepared, cured, and tested according to BS 8500 and BS 12390 standards. The study investigated the 28-day compressive strengths of six concrete mixes with varying CEM-I replacement levels (10%, 30%, 50%, and 70%) and different aggregate sources (recycled vs. virgin). A generic mix proportion of 1:2:4 was used to achieve design strengths of 10-20 MPa. The highest compressive strengths (23 MPa) were achieved by mixes with SB recycled aggregates but without 'filter cake,' indicating the suitability of such aggregates as greener alternatives to virgin aggregates. Mixes with 10% and 30% CEM-I replacement achieved compressive strengths of 16 MPa and 14 MPa, respectively, balancing CEM-I replacement and strength performance. Higher CEM-I replacements (50% and 70%) resulted in poor strength performance (7 MPa and below). This type of concrete is best suited for non-critical, non-load-bearing applications such as pavements, driveways, and backfill material in pipework.
Keywords
low-carbon, filter cake, circular economy, decarbonised, non-structural concrete, waste recycling.
DOI
10.5703/1288284318173
Recommended Citation
Shifa, Feysal; Muhit, Imrose B.; Hughes, David J.; and Suntharalingam, Thadsha, "Utilising 'Filter Cake' for Low-Carbon Non-structural Concrete: A Sustainable Approach to Waste Management" (2025). International Conference on Durability of Concrete Structures. 1.
https://docs.lib.purdue.edu/icdcs/2025/sce/1
Utilising 'Filter Cake' for Low-Carbon Non-structural Concrete: A Sustainable Approach to Waste Management
Scott Bros (SB) Ltd.’s recycling plant for soil and aggregate washing is projected to generate 225,000 tonnes of residual waste material, known as 'filter cake,' annually. This high-volume, low-value waste stream presents significant management and disposal challenges. This study explores the potential of using 'filter cake' as a raw material in low-carbon non-structural (non-standard) concrete production, contributing to the circular economy. The research aimed to develop low-carbon concrete by maximising recycled ingredients and minimising CEM-I content. Concrete cube samples (150 mm) were prepared, cured, and tested according to BS 8500 and BS 12390 standards. The study investigated the 28-day compressive strengths of six concrete mixes with varying CEM-I replacement levels (10%, 30%, 50%, and 70%) and different aggregate sources (recycled vs. virgin). A generic mix proportion of 1:2:4 was used to achieve design strengths of 10-20 MPa. The highest compressive strengths (23 MPa) were achieved by mixes with SB recycled aggregates but without 'filter cake,' indicating the suitability of such aggregates as greener alternatives to virgin aggregates. Mixes with 10% and 30% CEM-I replacement achieved compressive strengths of 16 MPa and 14 MPa, respectively, balancing CEM-I replacement and strength performance. Higher CEM-I replacements (50% and 70%) resulted in poor strength performance (7 MPa and below). This type of concrete is best suited for non-critical, non-load-bearing applications such as pavements, driveways, and backfill material in pipework.
