Development of Calcined-Clay and Hemp Hurd Composites for Construction

Author

Christopher Vreeland, University of New MexicoFollow

Publication Date

Summer 7-29-2025

Abstract

This research combines two alternative building materials in novel ways to create construction products that address current global challenges. Geopolymer cement is emerging as a high-performance, lower-impact alternative to ordinary Portland cement. It can provide equal or better strength and durability without producing considerable CO₂ emissions. Calcined clays are beneficial precursors due to their mineral properties and abundance, as well as mitigating future supply challenges that may come from shifting industrial activity. Additionally, hemp hurd is gaining popularity in construction for its thermal and hygroscopic properties. This inner core of the plant’s stalk is most used with Lime binder as a moisture buffering natural insulator, which also offers the added benefit of removing carbon dioxide from the atmosphere during its rapid growth. The downside of hemp-lime insulation is that it is non-load bearing and requires structural framing. In phase one of this study, two calcined-clay-based geopolymer cement pastes were developed. In phase two, the better-performing binder was paired with hemp hurd in three different ratios to examine the thresholds of adequate compressive strength and thermal performance. Mechanical performance and thermal conductivity were examined alongside a binder-only control. Additionally, minor characterization and durability trials were performed to gain insight into this understudied material combination. Results indicated that hemp hurd with geopolymer binder could meet both compressive strength and thermal conductivity expectations, only at very different ratios. This suggests the possibility of functionally graded composites made with only geopolymer cement paste and hemp hurd which can fit a variety of construction applications.

Keywords

Hemp Hurd, Hempcrete, Fiber Reinforced Concrete, Geopolymer, Sustainability, Carbon Negative

Document Type

Thesis

Language

English

Degree Name

Civil Engineering

Level of Degree

Masters

Department Name

Civil Engineering

First Committee Member (Chair)

Dr. Maryam Hojati

Second Committee Member

Dr. Susan Bogus-Halter

Third Committee Member

Franciso Uviña

Recommended Citation

Vreeland, Christopher. "Development of Calcined-Clay and Hemp Hurd Composites for Construction." (2025). https://digitalrepository.unm.edu/ce_etds/359