JOHN P. SPEWEIK
ABSTRACT
The evolution of masonry mortar over the last 275 years in America has been very interesting. Inventions and discoveries over this time period, in both Europe and America, directly impacted the way mortar is manufactured and used in today’s construction industry. Among the notable discoveries were Smeaton’s discovery of hydraulic lime in 1756, Joseph Aspdin’ s development of portland cement in 1824, and the introduction of masonry cement mortar in the late 1920s. Mixing mortar at the construction site has evolved from the hoe and shovel of the 1800s, to the gasoline and electric mortar mixers of the 1940s, to the highly sophisticated bulk silo systems of the 1990s. The standards that govern masonry mortars in the United States under The American Society for Testing and Materials have played an important role in the development of mortar, its use, and its applications. These standards and specifications have evolved as the technical knowledge of mortar has increased and, at the same time, the testing methods have improved.
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