Experimental study on the monitoring of concrete shrinkage based on intelligent string strain sensors

Abstract

Aiming at the phenomenon that shrinkage will generate tensile stresses inside the concrete structure and cause damage, thus forming a potential hazard to the engineering structure, as well as current incomplete research on the influence of reinforcement on the shrinkage of concrete, the study was carried out using intelligent string strain sensors to monitor the shrinkage of three specimens with different reinforcement ratios in a natural environment for nine months. The results show that: the intelligent string strain sensor can automatically record the strain and temperature, as well as the temperature correction in the shrinkage monitoring; in the natural environment, the effect of humidity on the concrete shrinkage is more obvious than the temperature, and when the coefficient of thermal expansion of the concrete and the sensor is closer to each other, it can offset the effect of the temperature on the shrinkage of the concrete; the shrinkage of reinforced concrete is not linearly decreasing with the increase in reinforcement rate at all ages. The shrinkage inhibition effect of steel reinforcement on concrete is obvious only when the reinforcement ratio reaches a certain amount.