Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled Materials

This study proposes that a proactive quality assurance (QA) framework for asphalt mixes with recycled materials, i.e., reclaimed asphalt pavement and recycled asphalt shingles, should be developed. Quality control (QC) is generally concerned with the contractor’s obligation to produce mixes which me...

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Main Authors: Eslam Deef-Allah, Magdy Abdelrahman
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Recycling
Subjects:
Online Access:https://www.mdpi.com/2313-4321/10/2/71
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author Eslam Deef-Allah
Magdy Abdelrahman
author_facet Eslam Deef-Allah
Magdy Abdelrahman
author_sort Eslam Deef-Allah
collection DOAJ
description This study proposes that a proactive quality assurance (QA) framework for asphalt mixes with recycled materials, i.e., reclaimed asphalt pavement and recycled asphalt shingles, should be developed. Quality control (QC) is generally concerned with the contractor’s obligation to produce mixes which meet the job mix formula (JMF) targets. However, QA considers the variability in fabrication processes and materials and offers monitoring by evaluating the contractor’s performance. Although both aggregate gradations and asphalt contents were within the JMF specifications, the recovered binders revealed significant differences from the contract binders in the JMF. Rheological tests indicated increased stiffness and elasticity but reduced capability to relax thermal stresses in binders recovered from plant–lab- and lab-fabricated mixtures, compared to field mixtures. Thermal-rheological analysis models corroborated these results by demonstrating reduced decomposition areas for more aged binders, enhancing performance prediction—especially for limited binder amounts. The creation of a QA decision matrix facilitated uniform, performance-oriented assessments. The matrix indicated only 23% of the mixtures satisfied JMF criteria and reported QC data—predominantly field mixtures—underscoring the impact of the fabrication mechanisms and the use of soft binders. This matrix integrates statistical analysis and binder performance assessments as a tool for verifying material compliance and tracking contractor efficiency. It reflects a transition from traditional QC toward a more proactive QA framework for sustainable pavements.
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spelling doaj-art-83b45da04c29494f9c2ae172d1f85b222025-08-20T02:28:33ZengMDPI AGRecycling2313-43212025-04-011027110.3390/recycling10020071Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled MaterialsEslam Deef-Allah0Magdy Abdelrahman1Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USADepartment of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USAThis study proposes that a proactive quality assurance (QA) framework for asphalt mixes with recycled materials, i.e., reclaimed asphalt pavement and recycled asphalt shingles, should be developed. Quality control (QC) is generally concerned with the contractor’s obligation to produce mixes which meet the job mix formula (JMF) targets. However, QA considers the variability in fabrication processes and materials and offers monitoring by evaluating the contractor’s performance. Although both aggregate gradations and asphalt contents were within the JMF specifications, the recovered binders revealed significant differences from the contract binders in the JMF. Rheological tests indicated increased stiffness and elasticity but reduced capability to relax thermal stresses in binders recovered from plant–lab- and lab-fabricated mixtures, compared to field mixtures. Thermal-rheological analysis models corroborated these results by demonstrating reduced decomposition areas for more aged binders, enhancing performance prediction—especially for limited binder amounts. The creation of a QA decision matrix facilitated uniform, performance-oriented assessments. The matrix indicated only 23% of the mixtures satisfied JMF criteria and reported QC data—predominantly field mixtures—underscoring the impact of the fabrication mechanisms and the use of soft binders. This matrix integrates statistical analysis and binder performance assessments as a tool for verifying material compliance and tracking contractor efficiency. It reflects a transition from traditional QC toward a more proactive QA framework for sustainable pavements.https://www.mdpi.com/2313-4321/10/2/71quality assuranceRAPRASdecision matrixinteractionsfabrication mechanism
spellingShingle Eslam Deef-Allah
Magdy Abdelrahman
Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled Materials
Recycling
quality assurance
RAP
RAS
decision matrix
interactions
fabrication mechanism
title Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled Materials
title_full Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled Materials
title_fullStr Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled Materials
title_full_unstemmed Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled Materials
title_short Quality Assurance Framework for Recovered Binders and Aggregates from Asphalt Mixtures Incorporating Recycled Materials
title_sort quality assurance framework for recovered binders and aggregates from asphalt mixtures incorporating recycled materials
topic quality assurance
RAP
RAS
decision matrix
interactions
fabrication mechanism
url https://www.mdpi.com/2313-4321/10/2/71
work_keys_str_mv AT eslamdeefallah qualityassuranceframeworkforrecoveredbindersandaggregatesfromasphaltmixturesincorporatingrecycledmaterials
AT magdyabdelrahman qualityassuranceframeworkforrecoveredbindersandaggregatesfromasphaltmixturesincorporatingrecycledmaterials