Evidence map›Paper›PMID 41785237›Full record

ArticlePloS one2026

High-performance eco-concrete beams with calcined montmorillonite, metakaolin pyrolyzed coffee grounds, and hybrid fibers for enhanced bending strength and microstructural refinement.

Amani Abdallah Hepautwa, Askwar Hilonga, Register Mrosso, Tusekile Alfredy, Gabriel Mwalusambo, Fina Lesafi, Yusufu Abeid Chande Jande

Abstract read
In one paragraph

Article in PloS one, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Amani Abdallah HepautwaDepartment of Materials and Energy Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.ORCID https://orcid.org/0009-0009-2209-2712
Askwar HilongaDepartment of Materials and Energy Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
Register MrossoDepartment of Materials and Energy Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
Tusekile AlfredyDepartment of Materials and Energy Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
Gabriel MwalusamboDepartment of Materials and Energy Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
Fina LesafiDepartment of Materials and Energy Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
Yusufu Abeid Chande JandeDepartment of Materials and Energy Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

This study investigates the flexural performance and microstructural evolution of reinforced concrete beams incorporating calcined montmorillonite (CMMT), metakaolin (MK), pyrolyzed coffee grounds (PCG), and hybrid fibers (steel or banana) as sustainable partial replacements for natural sand and cementitious binders. The replacement levels-12.5% SCM (CMMT or MK) and 15% PCG-were selected based on preliminary optimization trials and evidence from prior studies that identify these ranges as the threshold at which pozzolanic reactivity, workability, and particle packing achieve maximum benefit without compromising matrix integrity. Thirteen mix groups and a control beam were cast and tested under four-point bending, with three replicates per group. Statistical analysis using one-way ANOVA (α = 0.05) confirmed significant differences in peak load, stiffness, ductility, and energy absorption across mixes (p < 0.05). Beams containing CMMT and 1.5% steel fibers achieved the highest flexural capacity, exhibiting a 92-105% increase in ultimate load relative to the control, while mixes with 1.0% banana fibers demonstrated the greatest ductility and post-cracking deformation capacity. Improvements in stiffness (up to 68%) and energy absorption (up to 120%) were closely linked to microstructural refinement observed through XRD and SEM. Quantitative indicators-including a 22-34% reduction in portlandite peak intensity, an increase in amorphous C-S-H content, and visibly compacted interfacial transition zones-corroborated the enhanced matrix densification induced by CMMT and PCG.The combined use of PCG, CMMT, and natural/steel fibers significantly reduced reliance on natural sand and cement while improving structural performance, demonstrating a viable pathway for developing high-performance eco-concretes for structural applications. Although direct durability tests were not conducted, the observed microstructural densification suggests potential improvements in long-term resistance to moisture and chloride ingress, warranting further research.

Indexed as

BentoniteCoffeeConstruction MaterialsKaolinFlexural StrengthMaterials TestingBentoniteCoffeeKaolin

Identifiers

PMID41785237
PMCPMC12962494

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.