Title: Development of In-Place Test Methods for Evaluating Printable Concretes

Author(s): Christian Negron-McFarlane, Eric Kreiger, Lynette Barna, Peter Stynoski, and Megan Kreiger

Publication: Materials Journal

Volume: 121

Issue: 2

Appears on pages(s): 59-72

Keywords: additive construction (AC); flow table; fresh concrete; three-dimensional (3-D) printing; unconfined compression; volumetric proportioning

DOI: 10.14359/51740265

Date: 4/1/2024

Abstract:
An experimental investigation was carried out using the volumetric proportioning approach to achieve printable portland cement concrete mixtures. The types of aggregates investigated were rounded pea gravel and coarse and fine sand. The test matrix of potential concrete mixtures was prepared based on watercement ratios (w/c) of 0.46 to 0.48, sand-to-stone ratios (sa/st) of 1.18 to 1.91, and paste-aggregate ratios (p/a) of 0.74 to 0.81. The workability and early-age strength of fresh concrete were characterized by field-friendly flow-table and unconfined compressive strength (UCS) tests. Test results indicated that the w/c, sa/st, and p/a all significantly affect fresh concrete pumpability and early-age strength. The overall research results revealed that pumpability and buildability can be evaluated with these two tests. The results of these two tests together are used to define a printable region.