Date of Award

May 2026

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Civil Engineering

First Advisor

Sattar Dorafshan

Abstract

Rural culvert systems in cold regions like North Dakota face rising replacement needs due to aging infrastructure, harsh deterioration, and limited precast supply. Additive construction with concrete (ACC) offers promise but is constrained by proprietary mix designs, limited validation for non-linear geometries such as ring-type pipes, and challenges in reinforcement integration. This study addresses these gaps through three efforts. First, a non-proprietary mix (MIX7, w/c = 0.37) using local materials achieved optimal printability (190–200 mm flow) and 28‑day strengths of 55–60 MPa; full-scale 18‑inch pipes met ASTM C76 Class II/III requirements. Second, literature shows ACC permanent formwork performance depends on interfacial transition zone behavior, influenced by roughness, timing, shrinkage, and fibers. Third, composite tests of printed shells with early cast-in-place concrete (4–6 hours) achieved flexure-controlled failure without delamination. Key limitations include volumetric instability, permeability, interface characterization, reinforcement challenges, and lack of standardized design and modeling frameworks.

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