At the second stage were obtained diagrams for load- crack opening displacement for breaking homogeneously reinforced and layered fiber concrete prisms (with dimensions 10x10x40 cm) subjected to 4-point bending. Surface of fiber channel in concrete matrix after pull-out test (fiber angle to pulling out force direction 70°). For such mechanical behavior explanation, fiber channel in concrete surface microscopical experimental investigation, using microscope KEYENCE VHX2000, was performed. On the obtained force- displacement diagrams were observed jumps. Length of steel fiber was 26 mm, diameter 0.5 mm. In the first stage was examined pull-out process for steel fiber was embedded into a concrete by one end and was pulled out of concrete under the angle to pulling out force direction. Keywords: lightweight aggregate concrete,

As a result, the Crack Mouth Opening Displacement (CMOD) from the experimental tests was constructed and the fracture energy using inverse problem analysis was developed from the force-CMOD relationship in this study, respectively. Also, this study conducted the experimental tests with respect to normal and lightweight aggregate materials, in order to indentify the tensile crack failure of the concrete structures. Consequently, this study presents the performance characteristics of light-weight aggregate concrete materials due to the material properties and strength. On the other hand, the study of light-weight aggregate concrete materials has lack of data in comparison to the concrete structure using high strength materials, relatively. Therefore, in order to improve such problems, the light-weight aggregate concrete and high strength concrete materials have been studied during the past decades. Typically, the concrete structures has disadvantage of increasing the weight due to its mass in comparison to the strength of the materials. In recent years, with increase of construction of skyscraper structures, the study of concrete materials to improve their weight and performance has been emerging as a key of research area. It was seen that the CMOD and vertical load-point displacement computed using DIC analysis matches well with those measured experimentally. Digital images were captured before loading (unreformed state) and at different instances of loading and were analyzed using correlation techniques to compute the surface displacements, crack opening and sliding displacements, load-point displacement, crack length and crack tip location. For this study, nine geometrically similar beam specimens of different sizes with (steel fibers and glass fibers) and without fibers were tested under three-point bending in a closed loop servo-controlled machine with crack mouth opening displacement control with a rate of opening of 0.0005 mm/sec. This powerful innovative technique which is used to correlate two image segments to determine the similarity between them. DIC is advance measurement technique use to measure displacement of particle with very high accuracy. The main of objective of this paper is to develop new measurement technique without touching the object.

Two point hospital crack status