A method for identifying prestress force in single-span or multi-span PCI girder-bridges is provided. The method includes non-destructive steps for obtaining a set of parameters of the PCI girder-bridge under investigation, and combines various analyses to identify the change of prestress force. Therefore, the losses of prestress force are tracked and predicted. The method does not cause structural damages along the PCI girder-bridge, and the cost of the identification is significantly decreased.

Provided herein is an apparatus for assessing a fluorescence characteristic of a gemstone. The apparatus comprises an optically opaque platform for supporting a gemstone to be assessed, one or more light source to provide uniform UV and non-UV illumination, an image capturing component, and a telecentric lens positioned to provide fluorescent images of the illuminated gemstone to the image capturing component. Also provided are methods of fluorescence analysis based on images collected using such an apparatus.

The present invention relates to a quantitative evaluation method for concrete workability based on bottom resistance, including the following steps: step 1, carrying out a test for bottom resistance of fresh concrete; step 2, drawing a curve of inserting velocity of steel sheet over time; and step 3, quantitatively evaluating a concrete workability based on conditions of the bottom resistance. This method can quantitatively characterize the sinking condition of aggregate of the fresh concrete by effectively carrying out the test for bottom resistance of fresh concrete, calculating the inserting velocity of concrete and drawing the curves of displacement and velocity over time, so as to achieve the quantitative evaluation for concrete workability and overcome the defects of conventional methods that it is difficult to quantitatively characterize the segregation degree of concrete.

The purpose of the present invention is to provide a chemically-strengthened glass exhibiting both surface strength and abrasion-resistant anti-fingerprint (AFP) properties. The present invention relates to a plate-shaped chemically-strengthened glass which has a compressive stress layer provided to a glass surface layer, a glass surface hydrogen concentration profile in a specific range, and a surface strength and abrasion-resistant anti-fingerprint (AFP) properties which are in specific ranges.

A tester for evaluating pullout load capacity and bond quality of anchor bolts embedded in concrete includes a Schmidt hammer for measuring a rebound number and an ultrasonic pulse velocity tester for measuring the transit time of a pulse transmitted through concrete surrounding an anchor bolt. The rebound number and the transit time are combined and matched against a database record which identifies the pullout load capacity and the bond quality. The transit time is matched to thresholds of transit times associated with porosity, internal cracking, air voids, and water pockets located around the embedded anchor bolt. The Schmidt hammer is further modified by the incorporation of a digital level for measuring the vertical and horizontal angles of inclination of the plunger with the concrete surface, a guide tube for supporting the plunger, and by using a convex plunger tip for improved registration with anchor bolt head.

Methods, systems, and program products are disclosed for implementing acoustic logging and determining wellbore material characteristics. In some embodiments, a method may include determining a polar differential signal for each of one or more pairs of azimuthally offset acoustic measurements within a wellbore. A reference azimuth is identified based, at least in part, on comparing the polar differential signals to a modeled bonding differential signal within a target response window. The method further includes determining differences between an acoustic measurement at the reference azimuth and acoustic measurements at one or more other azimuths and determining a wellbore material condition based, at least in part, on the determined differences.

The present disclosure provides systems and methods for estimating the strength of a concrete foundation. The disclosed systems and methods can be used to estimate compressive strength of below-grade concrete without excavation. A method of estimating compressive strength may include determining compressive strength measurements corresponding to surface wave speeds for a plurality of concrete test specimens, determining a speed of surface waves in the concrete foundation, and estimating compressive strength of the concrete foundation based on the compressive strength measurements and corresponding surface wave speeds for the plurality of concrete test specimens and the speed of surface waves in the concrete foundation.

A device and method for measuring slump of concrete in a hopper feeding a concrete pump. A slump sensor generates a signal from either an ammeter to measure current from a power source feeding an electric motor being configured to rotate an agitator shaft or a pressure gauge configured to measure hydraulic pressure in a hydraulic drive hose passing between a hydraulic pump and a hydraulic motor configured to rotate the agitator shaft. A controlling computer includes a memory in which an operating range may reside, the operating range being a range from a lower slump signal value corresponding to a lower limit of slump value to an upper slump signal value. The controlling computer generates an alert signal when the slump sensor signal falls outside of the operating range. In one embodiment, the controlling computer stops the concrete pump when the alert signal is detected.

A sensing device includes a concave side adapted to conform to a curvature of an outer side of a standard concrete test cylinder, a temperature sensor, and a humidity sensor. In one embodiment, the sensing device includes a capillary needle disposed on the concave side. The capillary needle comprises a humidity sensor. The sensing device is attached to the side of a concrete test cylinder, temperature and humidity measurements are obtained by the sensing device, and a prediction of maturity and strength of the concrete is generated based on the temperature and humidity measurements.

A mixer vehicle includes a mixer drum, a first acceleration sensor, a second acceleration sensor, and a controller. The first acceleration sensor is configured to produce first acceleration signals and the second acceleration sensor is configured to measure accelerations within the mixer drum to produce second acceleration signals. The controller is configured to receive the first acceleration signals from the first acceleration sensor and second acceleration signals from the second acceleration sensor. The controller is further configured to determine a presence of material within the mixer drum based on the first acceleration signals and the second acceleration signals. The controller is further configured to determine one or more properties of the material within the mixer drum based on the first acceleration signals and the second acceleration signals.