Abstract: A robotic assembly (20) is provided which is adapted to traverse the surface of a member (138) for inspection and/or work on or about the surface of the member (138). The preferred assembly (20) includes two or more robots (10a-10c) spaced about the body (138) with a tether assembly (140) interconnecting the robots (10a-10c) in order to hold the latter in tractive engagement with the surface of the body (138). Each of the robots (10a-10c) includes rotatable traction wheel assemblies (16) which are independently controllable through respective drive motors (86), as well as independently controllable takeup reels (98) for adjusting the tension of the tether assembly (140). Each robot (10a-10c) preferably includes an elongated body (12) having four corner-mounted wheel assemblies (16) pivotally secured thereto, and a carriage (14) pivotally coupled to the body for pivoting thereof independently of the wheel assemblies (16) and about an axis transverse to the wheel assembly pivot axes.

Abstract: A prefabricated roadway expansion joint/load transfer assembly (10) is provided which accommodates normal expansion and contraction between adjacent slabs (90a, 90b) while transferring vertical shear loads and minimizing stress cracking of the surrounding concrete (90). The assembly (10) includes a plurality of X-configuration bar units (12) including crossed, unconnected metallic bars (20, 22) whose ends (24, 30, 28, 26) are embedded within the adjacent slabs (90a, 90b). The bar ends (24, 30, 28, 26) are coupled within the corresponding slabs (90a, 90b) through use of respective U-shaped coupling assemblies (14) each having spaced legs (38, 40) and a bight (42), and vertical tie rods (44). The individual bar units (12) are joined by laterally extending connecting rods (56-70). A central spacer (18) is supported by the bar units (12) and supplementary spring supports (76) and extends the full width of the assembly (10).

Abstract: An improved turbidimeter apparatus (10) is provided for accurate, rapid, field testing of fresh concrete mixes in order to determine the water-cement ratios thereof. The apparatus (10) includes an upright sieve chamber (12) adapted to receive a concrete sample (56), together with a turbidimeter (14); a recirculation system (16) is interposed between the chamber (12) and turbidimeter (14), and permits separation of the aggregate from the concrete sample (56) and formation of a dilute dispersion suitable for turbidimetric determinations. In use, dilute water-cement dispersions are created using the apparatus (10) and turbidimeter determinations are made via turbidimeter (14); these readings can then be used with standard, previously developed water-cement ratio versus turbidimeter reading curves to accurately measure the initial water-cement ratios of concrete mixes.

Abstract: A prefabricated roadway expansion joint/load transfer assembly (10) is provided which accommodates normal expansion and contraction between adjacent slabs (90a, 90b) while transferring vertical shear loads and minimizing stress cracking of the surrounding concrete (90). The assembly (10) includes a plurality of X-configuration bar units (12) including crossed, unconnected metallic bars (20, 22) whose ends (24, 30, 28, 26) are embedded within the adjacent slabs (90a, 90b). The bar ends (24, 30, 28, 26) are coupled within the corresponding slabs (90a, 90b) through use of respective U-shaped coupling assemblies (14) each having spaced legs (38, 40) and a bight (42) and vertical tie rods (44). The individual bar units (12) are joined by laterally extending connecting rods (56-70). A central spacer (18) is supported by the bar units (12) and supplementary spring supports (76) and extends the full width of the assembly (10).