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The paper relates to a research project carried out in the Department of Building, UMIST in conjunction with the Building Research Station into the development of techniques for the measurement of dimensional inaccuracies of strong height pre-cast concrete units up to 8 m long.
This resulted in the design of new and inexpensive instrumentation based on that already commercially available, which was applied to determine the degree of deviation to be expected in the production of these units. Particular emphasis is given to the measurement of form deviation, or twist, and the problems concerned with its determination in the factory environment. The inherent dimensional inconsistencies resulting from the material used and manufacturing processes is briefly reviewed.
The paper examines the validity of recognized metrological concepts in the context of the increasing emphasis upon prefabricated component assemblies as an integral part of the building process, and discusses the relationship between the requirements of accuracy control dictated by the assembly procedures on site and those likely to be achieved by the production processes in the factory. The problems of setting standards for tolerances in realistic terms are considered in the light of current practice in the detailing of this form of construction and are related to the production inaccuracies involved. [ABSTRACT FROM AUTHOR]