Abstract

This study explores the creation of environmentally friendly interior concrete finishes by recycling agricultural and industrial waste. In a 1:3 cementitious-to-aggregate mortar mix, the study investigates high-volume (30%) cement replacement using fly ash (FA30), biochar (BC30), and a hybrid combination (FAB30). It illustrates the viability of converting waste streams into workable architectural finishes through meticulous material investigation, mechanical testing, and aesthetic evaluation. Different performance characteristics were found by the technical examination. FA30 outperformed the control mix with a 14-day compressive strength of 8.00 MPa thanks to pozzolanic activity and decreased water demand. On the other hand, BC30 (7.33 MPa) significantly lost strength due to the large porosity and water absorption of biochar. An intermediate strength of 6.66 MPa was offered by FAB30. Biochar-containing mixtures failed gradually and non-catastrophically, according to failure mode analysis, confirming their suitability for non-structural interior applications. Strong appreciation for each finish's distinctive visual characteristics was found in an aesthetic perception research. The smooth, light-gray FA30 finish was seen as contemporary and polished. The speckled FAB30 finish, which was characterized as natural and energetic, was the most favored overall, while the charcoal-black BC30 finish generated thoughts of drama and luxury. Significant sustainability gains were found in the environmental evaluation: replacing cement resulted in an estimated 105 kg CO₂e per m³. Additionally, mixes that included biochar had an extra ~206 kg CO₂e per m³ sequestration capacity, making them possible carbon sinks. This work suggests a new direction for sustainable interior design by showing how waste-derived materials can offer practical, aesthetically pleasing interior finishes while addressing environmental issues. The findings extend the aesthetic and environmental potential of concrete beyond traditional uses by providing designers and architects with a scientifically supported framework for material choices.

Library of Congress Subject Headings

Concrete construction--Environmental aspects; Fly ash; Biochar; Building materials; Interior decoration

Publication Date

10-24-2025

Document Type

Thesis

Student Type

Graduate

Degree Name

Architecture (M.Arch.)

Department, Program, or Center

Architecture, Department of

College

Golisano Institute for Sustainability

Advisor

Seth H. Holmes

Advisor/Committee Member

Amanda Reis

Campus

RIT – Main Campus

Plan Codes

ARCH-MARCH

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