Using a Piezometer to Measure the Pressure of Groundwater

1. Determining the Compressive Strength of Concrete with a Concrete Strength Test Measuring the concrete strength is one of the most important stages in construction and engineering to ensure a high-quality build. While it is traditionally done using compression and tension testing machines, concrete strength tests may also be conducted using instruments like the Schmidt Hammer or an ultrasonic pulse velocity device. With these non-destructive tools engineers can analyse the extent of repair that must be conducted on a structure, or audit the final form of the structure. With either system the concrete’s actual compressive strength is determined as an estimate based on results from destructive tests in a lab matched to the velocity for UPV tests, or to the rebound hammers Q or R rebound values for Schmidt Hammer testing. A modern ultrasonic pulse velocity device comes with a touchscreen display and guarantees compatibility with a range of ultrasonic transducer. A material’s pulse velocity is affected by its elastic properties and density. In turn, those factors are related to the material’s strength and quality. Using ultrasonic wave velocity testing you should be able to accurately measure concrete’s sonic properties, identify a material’s homogenity, determine the presence of internal defects or imperfections like cracks and voids and concrete’s strength as it relates to specific standard requirements. It is useful when you need to determine the changes in concrete occurring over time or due to chemical attacks, frost, or fire. Time of flight is the basic value that is measured in an ultrasonic velocity test, and it pertains to the amount of time the ultrasonic pulse can travel from one transducer to another as it passes through a solid medium like concrete. Usually the measured ultrasonic pulse is identified as a compression wave or p-wave, and ultrasonic pulse velocity is determined by dividing the distance between sending and receiving transducers by the arrival time. The Schmidt hammer is another commonly used instrument for concrete strength tests. The Original Schmidt hammer is still widely used along with newer and advanced models like the Silver Schmidt hammer. Some manufacturers have upgraded the original Schmidt hammer with digital technology to make it more dependable and accurate and to remedy insufficiencies associated with classic hammers such as the rebound value being too dependent on impact direction and easily affected by internal friction. The Silver Schmidt hammer is highly accurate during data collection due to a differential optical absolute velocity encoder. Results do not depend on impact direction and it comes with a built-in correction module for form factor and carbonation to ensure higher accuracy.