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Masonry is an inert construction material with favorable thermal and mechanical properties. While masonry is widely used in buildings, the fire performance of this material has not received much attention over the years. This continues to hinder the understanding of the fire behavior of masonry. To bridge this knowledge gap, this study presents the results of an experimental campaign carried out on concrete masonry blocks (CMUs) to investigate fire-induced degradation of the compressive strength of CMUs under elevated temperatures and post-fire conditions. In this campaign, steady-state tests were conducted; wherein standard-sized CMUs are exposed to a heating scenario ranging from 25 to 800 C followed by cooling to ambient temperature. In addition, these tests were also complimented with a thermogravimetric (TGA) analysis to arrive at a comprehensive understanding of the degradation of the strength property of masonry. Results from the tests clearly show that the degradation in CMUs is lower than that typically observed in normal strength concrete. Furthermore, our findings also infer that masonry is capable of retaining a larger percentage of strength when tested under post-fire conditions as opposed to being under heating.

Three-dimensional (3D) printable concretes require high plastic yield stress to retain the shape of the printed layers, however, to enhance the ease of pumping the cementitious system should have as low a plastic yield stress as possible. To address these opposing needs for printing and pumping, a vibration-based active rheology-controlled system which temporarily reduces the plastic yield stress during pumping has been designed. To study the response of the rheological properties of the cementitious system and its response to vibrations, a test setup which can simulate the vibration that occurs during pumping has been developed. An EN445 flow cone was modified by mounting a frequency-controlled vibration setup. The effect of vibration on the flow initiation, flow topology, and flow rate of cementitious systems with three different water-to-binder ratios, two pozzolans (silica fume and metakaolin), and multiple dosage levels of high-range water reducer and viscosity modifying agents was studied. Results from this study suggest a strong correlation between plastic yield stress, and the frequency and amplitude of vibration with implications for 3D printing.