Measuring and monitoring short term stresses in concrete - using mercury-filled pressure pad connected to indicator capillary

摘要

A pressure measurement device for measuring and monitoring short duration stresses in concrete consists of a pressure and (1) placed on the concrete and connected to a measurement device (6) via a pipe (3). It gives accurate measurements whils being more compact than conventional devices without being more expensive. It does not require skilled operators. It has a very narrow cross-section measurement container (6). The pressure pad and connecting pipe are filled with mercury, the container being at least partially filled with mercury under a yielding preload. The expansion of the mercury in to the measurement container against the preload gives a measure of the stress in the concrete. The measurement chamber is a thick-walled capillary tube closed at the ends, filled with oil above the mercury, and with an oil-filled balance container (8) at the top.