Date of Graduation
5-2026
Document Type
Thesis
Degree Name
Master of Science in Civil Engineering (MSCE)
Degree Level
Graduate
Department
Civil Engineering
Advisor/Mentor
Barry, Michelle
Committee Member
Murray, Cameron
Second Committee Member
Hale, Micah
Keywords
3D Concrete Printing (3DCP); Additive Construction; Concrete Materials; Fine Aggregates; Mortar
Abstract
Recent advancements in the construction industry have introduced 3D printed concrete (3DPC) as a promising method for improving efficiency, precision, and design flexibility. Despite these advantages, 3DPC faces significant durability challenges, particularly due to the high cement paste contents in the mortar-type mixes and the various forms of shrinkage that occur at different stages of concrete setting and curing. The absence of formwork, increased surface exposure, and unique layer-by-layer deposition process inherent in 3D printing increase the risk of high plastic shrinkage strain, which can lead to premature cracking and compromise the durability of printed structures. Shrinkage can be even greater for concrete mixes made from indigenous soils containing silt and clay. This research explores the effects of various aggregate types and indigenous soils on the shrinkage and strength performance of printable mortar mixes. Indigenous soils were examined as a way to reduce the cost and logistical burdens associated with using commercial 3D mortar mixes or mixes using select quarried aggregates. While both plastic shrinkage and drying shrinkage are key drivers of deterioration in 3D printed mortar, drying shrinkage was the major area of focus in this study. A benchmark mix was defined and compared to a variety of mixes using different indigenous soils and additives. Fresh property tests were used to determine whether a mix was printable, and iterations in the mix design were carried out until a printable mix was created. Long-term drying shrinkage was measured using the length comparator through a modified version of the ASTM C157 test. Preliminary testing to measure the early age shrinkage was also carried out using digital cameras and image processing techniques. A variety of admixtures were also explored to reduce the higher drying shrinkage observed in printable mixes with indigenous materials containing high amounts of clay. This study aims to provide much-needed data related to the shrinkage cracking and overall durability of 3D printed concrete made from locally sourced aggregates and indigenous materials.
Citation
Olutunde, C. O. (2026). Strength and Shrinkage Performance of Commercial and Indigenous Mixes for 3D Concrete Printing. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6256
