Developing three-dimensional digital image correlation techniques to detect the surface smoothness of construction materials

A low-cost three-dimensional digital image correlation coefficient method, 3-D DIC equipped with one advanced digital camera and high-speed computer to detect the flatness of plaster of Paris casts is proposed in this research. The test and analysis results show that this proposed method can easily reveal the rugged surface of plaster cast. No matter what the absolute displacement, rotate on z-axis, strain on z-axis and von Mises strain of analysis results are extremely close to the real situation of this test sample. Then, the joint roughness coefficient (JRC) is used to compare the test results of 3-D DIC with the test results of laser scanner. These results indicate that the JRC values measured by laser scanner are very similar to that measured by 3-D DIC. Therefore, the accuracy degree of this 3-D DIC method is high enough for applying it to achieve the three-dimensional surface smoothness of construction material.