Abstract: A joint between adjacent concrete slabs for overcoming existing problems which occur due to large scale relative movement of adjacent concrete slabs which results from the slabs shrinking when aging. More specifically, a resilient finger joint for concrete slabs is provided which allows and adjusts for relative vertical movements of adjoining slabs with the joint including an arrangement for absorbing vibrations and impact loads encountered which result from traffic passing over the joint between adjacent slabs. The joint includes a plurality of fingers supported by a resilient bed. The fingers are positioned in staggered, interdigitated relation and each finger is associated with an anchor alongside of and partially overlapping one end of the adjacent finger with a pivot pin or shaft interconnecting the anchors and fingers with each finger including an end that is free of an opposing anchor but supported by the resilient bed.

Abstract: A concrete joint in concrete slab structures in which the joint includes an insert that is retained in centered position in a slot or recess formed in the upper surface of a concrete slab generally in alignment with a crack or fracture line extending downwardly from the slot or recess formed in the concrete slab. The bottom of the slot or recess is provided with a seal of cementitious material which extends completely across the bottom of the slot or recess and fills the crack or fracture line with the lower edge of the insert being inserted partially into the cementitious seal which is in the form of a quick setting sand and cement mixture which has high compression strength and low tensile strength and which will adhere to concrete surfaces but will not adhere to the insert. The space above the bottom seal on each side of the insert is then filled with a filler of an epoxy or similar material which encapsulates the spring clips and fills the slot or recess on both sides of the insert.

Abstract: A data processing system associated with a surface flatness measuring device, distinguishes between differential elevation signals respectively generated by an accelerometer type sensor while at rest and in motion. The readout of time-spaced data is thereby limited to those generated while the device is in steady state condition at rest in measuring positions, for collection of accurate data.