Claire B. Thomson1, Brad D. Weldon2, and Kevin Q. Walsh3
1)  Project Engineer, Enayat Schneider Smith Engineering, Inc., Denver, Colorado, USA
and formerly Graduate Engineering Research Assistant, New Mexico State University,
Las Cruces, New Mexico, USA
e-mail: clairebt2@icloud.com
2)  Associate Professor, Department of Civil Engineering, New Mexico State University,
Las Cruces, New Mexico, USA
e-mail: bweldon@nmsu.edu
3)  Asst. Teaching Professor & Director of Resiliency and Sustainability of Engr. Systems, Dept.
of Civil & Environmental Engineering & Earth Sciences, University of Notre Dame,
Notre Dame, Indiana, USA
e-mail: kwalsh8@nd.edu
and Senior Structural Engineer, Frost Engineering and Consulting,
Mishawaka, Indiana, USA
e-mail: kwalsh@frosteng.net

Keywords: mortarless masonry, interlocking masonry, out-of-plane, large-scale testing, airbag proof-testing, analytical methods

Abstract. This paper provides the results of an experimental research program on the material and structural performance of a novel, innovative type of masonry unit with the potential to provide safe and economic structures. The masonry block is a reinforced concrete block that uses a mortarless, interlocking connection and steel connection plates to form walls. An experimental program was conducted which investigated the individual block flexural strength and masonry prism flexural strength. The out-of-plane load-deflection behavior of the wall was determined through a large-scale testing method in which an airbag was used to apply a distributed pressure on the wall. Historically, masonry can be relatively weak under out-of-plane loading, but the connection techniques used for these particular masonry wall units are intended to provide adequate strength while also reducing the typical thickness of the wall and improving ease of construction. Strength characteristics for the units were determined and failure modes for the walls were evaluated. Generally, the novel wall system was determined to have adequate strength for most practical implications but lacked appropriate stiffness. The results of the testing will aid in the development of safe building methods and standards for construction and experimental testing of interlocking masonry units.