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Laser scanning generates a point cloud from which geometries can be extracted, but most methods struggle to do this automatically, especially for the entirety of an architecturally complex building (as opposed to that of a single façade). To address this issue, this paper introduces the Improved Slicing Method (ISM), an innovative and computationally-efficient method for three-dimensional building segmentation. The method is also able to detect opening boundaries even on roofs (e.g. chimneys), as well as a building's overall outer boundaries using a local density analysis technique. The proposed procedure is validated by its application to two architecturally complex, historic brick buildings. Accuracies of at least 86% were achieved, with computational times of as little as 0.53 sec for detecting features from a data set of 5.0 million points. The accuracy rivalled the current state of the art, while being up to six times faster, and with the further advantage of requiring no manual intervention or reliance on a priori information.

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This paper explores thermal transfer effects in Soundless Chemical Demolition Agents (SCDA). In a 10˚C water bath, quadrupling the volume of SCDA in a pipe accelerated peak hydration onset and resulted in a 700% increase in expansive pressure and a 20% increase in volumetric expansion. An equivalent sample in a constant temperature chamber showed almost 5°C greater hydration heat than in the water bath, which resulted in a six-fold expansive pressure difference after 4 days of testing and an order of magnitude more pressure in the first 24 hours, thereby demonstrating limitations of previous SCDA experimental work and providing a temperature based reason for discrepancies between large-scale testing and manufacturers' predictions. Since most construction projects have scheduling requirements, understanding how to achieve sufficiently high pressures within a single work shift is important for evaluating the field viability of SCDAs on a particular project.