养护湿度对混凝土微观结构和细观结构的影响OA

This study systematically discussed the influence mechanism of curing humidity on the microstructure and microstructure of concrete.A multi-scale comparative analysis was conducted on concrete under different curing humidity conditions.The tests included pore structure analysis,scanning electron microscopy(SEM),microhardness measurement,impermeability,and compressive strength tests,aiming to investigate the influence of microstructure on macro-mechanical properties.The test results showed that with the decrease of curing humidity,the pore structure parameters of concrete showed a significant downward trend.Compared with the standard curing environment,the pore structure parameters of concrete under outdoor natural curing condition deteriorated significantly.The test results of SEM showed that the structure of the interface transition zone under standard curing humidity was dense,and the number of micro cracks was less.There were more micro cracks and defects in the interface transition zone under outdoor curing environment,and the degree of structural porosity was significantly increased.The microhardness test further proved that the microhardness value of the interface transition zone in the standard curing environment was higher than that in the outdoor curing environment.The macro performance test data showed that the curing humidity had a decisive effect on the mechanical properties of concrete.In the impermeability test,the test block under the standard curing humidity had excellent impermeability,reaching 1.2 MPa water pressure without water seepage,while the test block under the outdoor environment reached 0.4 MPa water pressure.At the same time,the compressive strength of the test block in the standard curing humidity was 36.2 MPa,while the compressive strength of the test block in the outdoor curing humidity was only 24.5 MPa.To sum up,the change of curing humidity not only significantly affected the micro and structural characteristics of concrete,but also showed obvious response differences in the macro mechanical properties.