Applying flow measurement theory and the structural characteristics of optical fiber, flow measurement of paste can be achieved through a combined laser Doppler and optical fiber sensing system based on the principle of optical fiber grating sensors and flow sensors. The system is developed to. However, they are prone to decay from cement paste carbonation. In. In this study, a home-built Rayleigh scattering based optical frequency domain reflectometry (OFDR) technique is used for the measurement of strain distribution in a loaded cement paste.