Abstract: A method and apparatus for analyzing bituminous concrete mixes to predict the likelihood of early rutting is disclosed. A test head designed to be used in a gyratory compactor uses the compaction provided by the gyratory compactor to analyze bituminous mixes to determine whether they are likely to prematurely rut. A test specimen of bituminous mix is prepared to a specified air void content and then heated to a constant temperature and placed in the gyratory compactor. The test head, which consists of a hard rubber block in the shape of a truncated cone mounted in the direct center of a flat, metal circular disk, is placed on top of the specimen in the gyratory compactor with the rubber head down and engaging the test specimen. Once compaction is completed, mix specimen compaction data is analyzed to ascertain the degree of mix deformation for a specified number of gyrations, to thereby predict whether the mix is likely to prematurely rut.

Abstract: A reusable apparatus for forming in situ concrete test specimens comprises a flexible open outer container and a series of smaller closable cylinders for placement within the larger container. The assembly is placed within a depression formed in the wet concrete when the slab is poured, with outer and inner containers being filled with representative concrete of the slab. The assembly is left for the concrete to cure, with smaller containers removed from the larger container after curing. Apparatus is included for facilitating lifting the sample from the slab, after curing. The larger portion of surrounding concrete is then broken away to access the smaller cylinders, which may be shipped to a testing facility where the inexpensive containers are removed to expose the test specimens. The larger outer container may be flexed to remove it from the depression, and the depression filled with fresh concrete to repair the test site.

Abstract: To prevent a skid panel attached with wear resistance material of porcelain tiles or the like on its surface from warping in a longitudinal direction of laying the skid panel, a warp amount of a skid panel is predictively calculated from shrinkage strain, shrinkage force and upper and lower edge stresses of concrete, reverse camber is provided in the longitudinal direction of a mold of the skid panel with tensioning devices to nullify the final warp amount and concrete is fed to the mold to thereby fabricate the panel.

Abstract: There is a difficulty in workability of installing an optical fiber cable on a concrete structure, and when the optical fiber cable is installed on the surface of the concrete structure, the appearance of the concrete structure is spoilt by cutting the surface of the concrete structure or the like. Accordingly, there are provided a sheet-like strain sensor for confirming progress of damage of a concrete structure, in which one or a plurality of optical fiber cables are fixedly held between sheet-like bodies which are easy for the adhesive to permeate while one end/ends of the optical fiber cable/cables are pulled out; and a method for confirming progress of damage of a concrete structure by measuring strain by use of the one end of the optical fiber cable pulled out between the sheet-like bodies.

Abstract: Disclosed are a testing apparatus for and a method of measuring thermal stresses of concrete structures. Overcoming the limitations that conventional analytical access techniques have, the apparatus opens a new way to conveniently measure the thermal stress attributable to the heat of hydration generated in concrete structures indoors. Using a material different in coefficient of thermal expansion from concrete, the apparatus can directly measure the change in thermal stress of the concrete which is subjected to internal and/or external confinement. By using various materials, the thermal stress which varies depending on the confinement extent can be inferred. Additionally, an accurate prediction of the thermal stresses generated actually in concrete can be obtained, reflecting unclear physical properties of early-age concrete.

Abstract: There is disclosed a method and apparatus for testing the static load-bearing capacity of a pile, wherein a test load is applied to the top of the pile (2) by way of a jack (1) braced against a reaction member (3) and the magnitude of the test load and the resulting displacement of the pile are measured and communicated to an electronic computer (7). The electronic computer (7) issues control signals to the jack (1) in response to the measured magnitude of the test load so as to apply a predetermined regime of test loads to the top of the pile (2). By automatically monitoring the applied test load, it is possible to maintain a desired load with a high level of accuracy for an extended period of time without the need for operator intervention.

Abstract: A reusable apparatus for forming in situ concrete test specimens comprises a flexible open outer container and a series of smaller closable cylinders for placement within the larger container. The assembly is placed within a depression formed in the wet concrete when the slab is poured, with outer and inner containers being filled with representative concrete of the slab. The assembly is left for the concrete to cure, with smaller containers removed from the larger container after curing. Apparatus is included for facilitating lifting the sample from the slab, after curing. The larger portion of surrounding concrete is then broken away to access the smaller cylinders, which may be shipped to a testing facility where the inexpensive containers are removed to expose the test specimens. The larger outer containers may be flexed to remove it from the depression, and the depression filled with fresh concrete to repair the test site.

Abstract: The present invention provides a method and apparatus for recording vehicle motion. The self-contained vehicle motion recorder apparatus is a sealed unit that contains at least a power source, and controller, sensor and recording devices. The controller device includes a power consumption manager that manages and conserves the overall power consumption of the apparatus. A sensor device is further included in operable communication with the controller device that produces signals that represent the vehicle's motion as a function of time. Additionally, a recording element is provided in operable communication with the controller for storing data that corresponds to the signals. A communication interface is further provided such that data may be read from the apparatus and commands and data may be written into the apparatus, from an external device.

Abstract: A method of determining the compressive strength path of a mortar or concrete mix is presented. The method includes: (a) conducting a series of tests by directing a jet of gas at gradually increasing pressure onto a surface of a freshly mixed test batch of mortar or concrete mix, monitoring the surface of the test sample and recording the pressure of the gas jet at which erosion resistance of the sample surface breaks down; (b) averaging the recorded gas pressure of the tests to obtain a strength index for the sample, and; © relating the strength index to predetermined set index of mortar or concrete compression strength.

Abstract: A nondestructive detection apparatus for detecting tendon failures in a prestressed concrete slab. The detection apparatus includes a cart adapted to be moved over the prestressed concrete slab. A metal sensor and a distance meter are connected to the cart. As the cart is moved over the slab, the metal sensor takes readings of a length of tendon and the distance meter measures the distance traversed by the cart. The detection apparatus also includes a controller that interfaces with the metal sensor and the distance meter. The controller is constructed and arranged to sample the readings generated by the metal sensor at predetermined distance intervals traversed by the cart.

Abstract: An free water measurement apparatus and device for measuring the free water that separates from the cement slurry as a matter of time during curing. There is also provided an apparatus and method for measuring the free water that separates from the cement slurry under the temperature and pressure conditions the cement slurry will encounter in the well-bore of an oil and gas well. The apparatus and method provided may further measure the compressive strength measurement of the cement slurry as it is cured.

Abstract: Method and apparatus for measuring in situ the strain and stress of concrete, and having an initial stress resulting from existing stress in the concrete and stress caused from varying externally applied forces on the concrete, by placing a strain gauge on an outer face of the concrete and reading the output to determine an original baseline reading, then cutting spaced slots above and below the gauge to define a segment of the concrete, placing flat jacks into the slots, pressurizing the flat jacks to restore the initial strain to the original baseline reading in the gauge to determine the initial stress in the segment, as alternatives, then leaving the flat jacks pressurized with constant pressure in the slots to measure variations in the strain in the segment over a period of time caused by creep in the concrete, or determining the modulus of elasticity of the concrete by incrementally varying the pressure on the segments while measuring corresponding strain, or adding an adjacent strain gauge to measure t

Abstract: The present invention is directed to a system for continuous physical integrity monitoring of large civil structures such as bridges and high-rise buildings . . . wherein the relevant sensor data stream is generated continuously and transmitted to the data gathering location without the need for an incoming triggering signal of any kind; i.e., it is a one way transmission system. Specifically, it is a concept for an interlinked multi-parameter Early Warning Sensor system with a full time data management capability for structures. The invention is also directed to both the system construction, with its communication capability, and also designs of specific sensors applicable to the system as a whole. As a practical example of application of the present invention to a structure, the description in this application is directed primarily towards system applications for bridge integrity early warning systems.

Abstract: Arresting material test apparatus, test probes and test methods enable testing of compressive gradient strength of cellular concrete, and materials having similar characteristics, on a continuous basis from the surface of a section to a typical internal penetration depth of at least 60 percent of thickness. Previous testing of cellular concrete typically focused on testing to confirm a minimum structural strength prior to structural failure or shattering of a test sample. For an aircraft arresting bed, for example, cellular concrete must exhibit a compressive gradient strength in a relatively narrow precalculated range continuously from the surface to penetration depth equal to 60 to 80 percent of sample thickness. Precalculated and controlled compressive gradient strength is critical to enabling an aircraft to be safely stopped within a set distance, without giving rise to drag forces exceeding main landing gear structural limits.

Abstract: A torque actuated tensile tester for proof loading anchors includes: an actuator, a left hand square nut, a right hand jam nut, an anchor head carrier, a housing, a slip gauge, and a keeper clip. The actuator has a cross-threaded portion and a portion engageable by a torque applying member. The housing has first and second ends, with the first end positionable circumjacent the anchor to be proof loaded and that is engageable with the structure to which the anchor is affixed. The left hand square nut is internally threaded with a single left hand thread that is engageable with the threaded portion of the actuator. The right hand jam nut is internally threaded with a single right hand thread that is engageable with the threaded portion of the actuator. The anchor head carrier is internally threaded with a single right hand thread that is engageable with the threaded portion of the actuator. The anchor head carrier has a flanged slot for receiving the head of an anchor for engagement.

Abstract: The extrusion moldability of particle-reinforced composites under fresh cition relative to the extruding pressure and extruding velocity can be pre-estimated from the cohesion and the coefficient of internal friction of the composite which can be calculated from the relationship of, when a frame divided into the upper and lower halves are filled with the composite and the upper and lower halves of the frame are displaced relative to each other in the horizontal direction under a pressure on the composite filling the frame, the shear stress of the composite against slip deformation.

Abstract: A hydraulic jack assembly is interposed between at least a pair of adjacent sections of the pile, and a hollow center is defined in a central region of the hydraulic jack assembly, thereby allowing communication between adjacent sections of the pile. Thus, concrete can be filled into the shaft without creating any voids, in particular around the hydraulic jack assembly. Therefore, the integrity of the pile is not compromised by the presence of the hydraulic jack assembly, and the testing device in no way detracts from the performance of the pile. The hydraulic jack assembly may consist of an annular arrangement of individual hydraulic jacks or may consist of a single cylinder device defining an annular cylinder chamber between a pair of coaxial, mutually slidable cylinders.

Abstract: A method of testing concrete in a structure in situ, by: directing a succession of pulses of laser radiation at a point on the structure so that each pulse effects removal of a quantity of concrete and transfers energy to the concrete; detecting a characteristic of energy which has been transferred to the concrete; determining, separately from the detecting step, the total quantity of concrete removed by the succession of pulses; and calculating a property of the concrete on the basis of the detected energy characteristic and the determined total quantity of concrete removed.

Abstract: A method and apparatus for testing the load-bearing capacity of a subterranean formation surrounding a concrete shaft and is made up of an expansion chamber at the bottom of the hole containing the shaft and fluid pressure and return lines which extend downwardly into communication with spaced outer peripheral portions of the expansion chamber so that when fluid is pumped into the chamber any entrapped air can be removed through the return line, and when grout is subsequently pumped into the chamber any fluid can be displaced through the return line. Telltale measuring rods extend downwardly into contact with spaced outer peripheral portions of the expansion chamber to measure displacement of the chamber when pressurized fluid is delivered into the chamber. The method of testing may be applied also in cyclical loading of the formation beneath the shaft to simulate a support structure which undergoes large fluctuations in loading, for example, of the type induced by an earthquake.

Abstract: A rotating testing device can be connected to a base unit. A temperature sensor can also be connected to the base unit. The testing device has probe heads. The probe heads are immersed and rotated in the liquid concrete and the force required for rotation is measured in the base unit. Various concrete recipes are stored in a memory of the base unit. Data concerning the concrete are calculated by comparison with the force required to rotate the testing device with the force derived from a respective stored characteristic line and are read from a display field. A concrete recipe and specific measurements are selected by actuating keys which select the respective electronic processes in the base unit for measurement and comparison with stored characteristic data.

Abstract: A method and apparatus is disclosed for measuring on-site expansive volumetric changes in hardened, shrinkage-compensated concrete samples. The sample is disposed in a cylindrical container having a strain gauge for measuring hoop stress which is correlated with expansion of the sample.

Abstract: The present invention relates to a method of instrumenting an already erected concrete or rock structure in order to determine the state of deformation of that structure. A cylindrical inclusion made of concrete having substantially the same mechanical properties as the concrete or the rock of the structure is inserted into a hole drilled into the concrete or rock. Sensors capable of detecting deformations are embedded in the concrete of the inclusion. The empty space between the inclusion and the hole is tightly filled with a grout whereby any deformation of the concrete or rock structure also deforms the inclusion and is therefore detected by the sensors embedded therein. The invention also extends to the inclusion and the so instrumented concrete or rock structure.

Abstract: It is described a process and an apparatus in which the cure of the concrete is accelerated by raising the temperature and moisture values in the environment in which the cure is taking place. The process comprises the following steps: making up at least a test piece obtained through the casting of a predetermined amount of concrete to be tested into a hollow mold; introducing the made up test piece into a vessel; adjusting the chemico-physical parameters of the environment in the vessel, following predetermined operating steps; operating a device adapted to measure the compression strength of the test piece, which brings about the generation of signals depending upon the measured compression strength; processing and displaying the signals.

Abstract: A method for predicting and controlling the strength development of concrete includes placing test concrete having the same composition as the subject concrete in a vessel which may be temperature regulated. The temperature inside the vessel is measured and recorded in a data memory and a data processor. The data is transmitted either in real time or from the data memory and data processor by way of a data transmission line to a temperature regulator for regulating the temperature inside the vessel. The temperature history of the test concrete can then simulate the temperature history of the reference concrete. The strength of the test concrete is measured at different times and the strength data of the test concrete is collected, processed and interpreted. A vessel for receiving the test concrete, a temperature regulator, a temperature controlling unit, a data recorder, a data transmitter and a computer are included.

Abstract: The method and apparatus for the non-destructive evaluation of a concrete mass uses the maturity method for evaluating the strength and durability of the concrete mass. The apparatus employs sensors which are implanted in the concrete along with a microprocessor and non-volatile RAM or EEPROM. A microcomputer is used periodically to up load the RAM and to make an evaluation of the concrete mass.

Abstract: A method of measuring the compactibility of a fresh concrete mass, for obtaining information of the applicability of the mass with respect to the strength properties of the cast product. A sample (20) having a determined weight (m) is taken from the mass and compressed in two opposite directions with a constant force (P) and subjected to a shearing compaction between two slanting planes (13, 14) which extend in parallel with each other and alter their positions through rotation. The volume (V, V.sub.t) of the sample is determined at the beginning of the compaction and after a pre-determined compaction work, whereafter the volume change of the sample is compared with experimentally defined limit values. The apparatus comprises a compacting device for subjecting the sample in a container to a shearing compaction, and elements for maintaining the sample under compression during the compaction.

Abstract: This invention is a testing device for concrete having a cylindrical housing adapted to be inserted in a preformed or drilled cylindrical hole in the concrete. The lower end of the cylindrical housing has one or more openings equi-distantly spaced. These openings have bearing shoes therein which are forced outwardly against the concrete by eccentric cams or a force rod which bears against the bearing shoes. A measuring device connected to the cams or force rod measures the pressure on the shoes and a distance which they extend into the concrete to measure the modulus of elasticity of the concrete from which the ultimate compressive strength of the concrete and other parameters may be determined. The device may be calibrated to yield the ultimate compressive strength directly.

Abstract: The measuring-value sensor according to the present invention for the measurement of extensions, for example in concrete or shotcrete, consists of a support member, having an extension stiffness value that is lower than the extension stiffness value of the material diameter displaced by the sensor. Transverse elements are located at either end of the support member, which induce the impact. By combining sufficiently large transverse elements that have a relatively high flexural strength and a support member that has the above-mentioned very low extension stiffness value it is made sure that extensions in the concrete are forced completely and without obstruction upon the support member by means of the transverse elements, so that when measuring the extension of the support member, the extension of the concrete is measured directly and without any distortion. The support member is suitably a hollow profile of aluminum or a plastic material, into which an additional profile, e.g.

Abstract: A fluid chamber assembly having an improved shape to enhance the reception of the first arrival of the signal from the transmitter transducer which has passed through the cement or fluid sample within the fluid chamber assembly and an improved sealing arrangement for the fluid chamber assembly.

Abstract: A method and apparatus for measuring the in situ strength of concrete containing aggregate particles of varying sizes in which a test member having at least one reacting surface is placed in the path of the concrete when the concrete is in the plastic state so that when the concrete is hardened, the test member is embedded therein. A force is then applied to the test member after the concrete has hardened tending to move the test member so as to cause the reacting surface to exert a compressive force on a portion of the hardened concrete of sufficient magnitude to create a rupture surface in the concrete. The large aggregate particles are screened out of the expected location in the concrete of the rupture surface so that large aggregate will not affect the test results.

Abstract: The ultra-flat pressure plate material tester for sounding concrete, comprises two facing side plates in the form of circular segments, of which the circular edges are turned back inwards by more than 90.degree. and assembled against one another by a flexible weld. The rectilinear edges of the side plates are assembled by using a U shaped obturator. Two elements for coupling to the hydraulic circuit are provided.

Abstract: A test machine for determining the strength of concrete which is suitable to perform quality tests of structures or structural elements within the plant or at the site. The machine has a loading unit provided with a force measuring means. A breaking cup is embedded in the concrete to be tested when it is wet, an extractor head being fixed to the breaking cup, serving for extraction thereof from the solidified concrete, and between the force measuring means and the extractor head there is inserted a joint ending in a releasable connecting piece.

Abstract: A device and procedure for measuring the strength of brittle material such as concrete in which a measurable torque is applied to a body member embedded in the material. The body member has a reacting surface which contacts a portion of the material to be tested and exerts a compressive force thereon in response to the application of torque to the body member. A thin layer of compressible material is provided on the body member adjacent the reacting surface to ensure unimpeded localized rupture of the material during the test. Torque is applied to the body member through an elongated rod which has one end secured to the body member and the opposite end extending outwardly from a surface of the material. In a preferred embodiment, the elongated rod is first turned in one direction to break the bond between the material and the device and turned in the opposite direction to apply the compressive force to a portion of the material.

Abstract: A device for measuring movements or deformations has at least one pair of variable reactance movement pick-ups, each pick-up comprising transducer elements whereby a modified inductive or capacitive reactance signal is generated by each pick-up in response to the movements or deformations. The variations of the reactances of the two pick-ups are arranged to be equal but opposite. An electrical oscillator is connected alternately to the two pick-ups by automatic switching elements, and each pick-up alters the oscillation frequency in dependence upon the variation of its reactance. The required measurement is derived from the difference between the two altered frequencies.

Abstract: Immediate estimation of compressive strength of concrete at the standard curing age of concrete of 28 days being not affected by the weathering of cement used in the concrete is carried out by the addition of an alkali hydroxide as well as a setting accelerator to the mortar portion obtained by wet screening of fresh concrete.

Abstract: A method and apparatus for testing the impact strength of materials which is especially effective for testing the impact strength of fiber reinforced concrete.